Lamictal Drug Information

Generic name: LAMOTRIGINE

Anti-epileptic Agent [EPC] Mood Stabilizer [EPC]

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Uses of Lamictal

is indicated for:
adjunctive therapy for primary generalized tonic-clonic seizures (PGTC) and partial-onset seizures with or without secondary generalization in patients aged 13 years and older. ( 1.1 )
conversion to monotherapy in patients aged 13 years and older with partial-onset seizures who are receiving treatment with a single antiepileptic drug (AED). ( 1.2 ) Limitation of use: Safety and effectiveness in patients younger than 13 years have not been established. ( 1.3 ) 1.1 Adjunctive Therapy LAMICTAL XR is indicated as adjunctive therapy for primary generalized tonic-clonic (PGTC) seizures and partial-onset seizures with or without secondary generalization in patients aged 13 years and older. 1.2 Monotherapy LAMICTAL XR is indicated for conversion to monotherapy in patients aged 13 years and older with partial-onset seizures who are receiving treatment with a single antiepileptic drug (AED). Safety and effectiveness of LAMICTAL XR have not been established (1) as initial monotherapy or (2) for simultaneous conversion to monotherapy from 2 or more concomitant AEDs. 1.3 Limitation of Use Safety and effectiveness of LAMICTAL XR for use in patients younger than 13 years have not been established.

Dosage & Administration of Lamictal

^a Valproate has been shown to inhibit glucuronidation and decrease the apparent clearance of lamotrigine [see Drug Interactions (7), Clinical Pharmacology (12.3)]. ^b Drugs that induce lamotrigine glucuronidation and increase clearance, other than the specified AEDs, include estrogen-containing oral contraceptives, rifampin, and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir. Dosing recommendations for estrogen-containing products, including oral contraceptives, and the protease inhibitor atazanavir/ritonavir can be found in General Dosing Considerations [see Dosage and Administration (2.1)]. Patients on rifampin and the protease inhibitor lopinavir/ritonavir should follow the same dosing titration/maintenance regimen used with AEDs that induce glucuronidation and increase clearance [see Dosage and Administration (2.1), Drug Interactions (7), Clinical Pharmacology (12.3)]. ^c Dose increases at Week 8 or later should not exceed 100 mg daily at weekly intervals.
	In Patients TAKING Valproate^a	In Patients NOT TAKING Carbamazepine, Phenytoin, Phenobarbital, Primidone,^b or Valproate^a
Weeks 1 and 2	25 mg every other day
Weeks 3 and 4	25 mg every day
Week 5	50 mg every day
Week 6	100 mg every day
Week 7	150 mg every day
Maintenance range (Week 8 and onward)	200 to 250 mg every day^c

Side Effects of Lamictal

The following serious adverse reactions are described in more detail in the Warnings and Precautions section of the labeling:
Serious Skin Rashes [see Warnings and Precautions ( 5.1 )]
Hemophagocytic Lymphohistiocytosis [see Warnings and Precautions ( 5.2 )]
Multiorgan Hypersensitivity Reactions and Organ Failure [see Warnings and Precautions ( 5.3 )]
Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions ( 5.4 )]
Blood Dyscrasias [see Warnings and Precautions ( 5.5 )]
Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.6 )]
Aseptic Meningitis [see Warnings and Precautions ( 5.7 )]
Withdrawal Seizures [see Warnings and Precautions ( 5.10 )]
Status Epilepticus [see Warnings and Precautions ( 5.11 )]
Most common adverse reactions with use as adjunctive therapy (treatment difference between LAMICTAL XR and placebo ≥4%) were dizziness, tremor/intention tremor, vomiting, and diplopia. ( 6.1 )
Most common adverse reactions with use as monotherapy were similar to those seen with previous trials conducted with immediate-release lamotrigine and LAMICTAL XR. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact GlaxoSmithKline at 1-888-825-5249 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trial Experience with LAMICTAL XR for Treatment of Primary Generalized Tonic-Clonic and Partial-Onset Seizures Most Common Adverse Reactions in Clinical Trials Adjunctive Therapy in Patients with Epilepsy: Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. In these 2 trials, adverse reactions led to withdrawal of 4 (2%) patients in the group receiving placebo and 10 (5%) patients in the group receiving LAMICTAL XR. Dizziness was the most common reason for withdrawal in the group receiving LAMICTAL XR (5 patients [3%]). The next most common adverse reactions leading to withdrawal in 2 patients each (1%) were rash, headache, nausea, and nystagmus. Table 4 displays the incidence of adverse reactions in these two 19-week, double-blind, placebo-controlled trials of patients with PGTC and partial onset seizures. Table 4. Adverse Reactions in Pooled, Placebo-Controlled, Adjunctive Trials in Patients with Epilepsy a a Adverse reactions that occurred in at least 2% of patients treated with LAMICTAL XR and at a greater incidence than placebo. Body System/ Adverse Reaction Percent of Patients Receiving Adjunctive LAMICTAL XR (n = 190) Percent of Patients Receiving Adjunctive Placebo (n = 195) Ear and labyrinth disorders Vertigo 3 <1 Eye disorders Diplopia 5 <1 Vision blurred 3 2 Gastrointestinal disorders Nausea 7 4 Vomiting 6 3 Diarrhea 5 3 Constipation 2 <1 Dry mouth 2 1 General disorders and administration site conditions Asthenia and fatigue 6 4 Infections and infestations Sinusitis 2 1 Metabolic and nutritional disorders Anorexia 3 2 Musculoskeletal and connective tissue disorder Myalgia 2 0 Nervous system Dizziness 14 6 Tremor and intention tremor 6 1 Somnolence 5 3 Cerebellar coordination and balance disorder 3 0 Nystagmus 2 <1 Psychiatric disorders Depression 3 <1 Anxiety 3 0 Respiratory, thoracic, and mediastinal disorders Pharyngolaryngeal pain 3 2 Vascular disorder Hot flush 2 0 Note: In these trials the incidence of nonserious rash was 2% for LAMICTAL XR and 3% for placebo. In clinical trials evaluating immediate-release lamotrigine, the rate of serious rash was 0.3% in adults on adjunctive therapy for epilepsy [see Boxed Warning ] . Adverse reactions were also analyzed to assess the incidence of the onset of an event in the titration period, and in the maintenance period, and if adverse reactions occurring in the titration phase persisted in the maintenance phase. The incidence for many adverse reactions caused by treatment with LAMICTAL XR was increased relative to placebo (i.e., treatment difference between LAMICTAL XR and placebo ≥2%) in either the titration or maintenance phases of the trial. During the titration phase, an increased incidence (shown in descending order of percent treatment difference) was observed for diarrhea, nausea, vomiting, somnolence, vertigo, myalgia, hot flush, and anxiety. During the maintenance phase, an increased incidence was observed for dizziness, tremor, and diplopia. Some adverse reactions developing in the titration phase were notable for persisting (>7 days) into the maintenance phase. These persistent adverse reactions included somnolence and dizziness. There were inadequate data to evaluate the effect of dose and/or concentration on the incidence of adverse reactions because, although patients were randomized to different target doses based upon concomitant AEDs, the plasma exposure was expected to be generally similar among all patients receiving different doses. However, in a randomized, parallel trial comparing placebo with 300 and 500 mg/day of immediate-release lamotrigine, the incidence of the most common adverse reactions ( > 5%) such as ataxia, blurred vision, diplopia, and dizziness were dose related. Less common adverse reactions (<5%) were not assessed for dose-response relationships. Monotherapy in Patients with Epilepsy: Adverse reactions observed in this trial were generally similar to those observed and attributed to drug in adjunctive and monotherapy immediate-release lamotrigine and adjunctive LAMICTAL XR placebo-controlled trials. Only 2 adverse events, nasopharyngitis and upper respiratory tract infection, were observed at a rate of > 3% and not reported at a similar rate in previous trials. Because this trial did not include a placebo control group, causality could not be established [see Clinical Studies ( 14.3 )] . 6.2 Other Adverse Reactions Observed during the Clinical Development of Immediate-Release Lamotrigine All reported reactions are included except those already listed in the previous tables or elsewhere in the labeling, those too general to be informative, and those not reasonably associated with the use of the drug. Adjunctive Therapy in Adults with Epilepsy In addition to the adverse reactions reported above from the development of LAMICTAL XR, the following adverse reactions with an uncertain relationship to lamotrigine were reported during the clinical development of immediate-release lamotrigine for treatment of epilepsy in adults. These reactions occurred in ≥2% of patients receiving immediate-release lamotrigine and more frequently than in the placebo group. Body as a Whole: Headache, flu syndrome, fever, neck pain. Musculoskeletal: Arthralgia. Nervous: Insomnia, convulsion, irritability, speech disorder, concentration disturbance. Respiratory: Pharyngitis, cough increased. Skin and Appendages: Rash, pruritus. Urogenital (female patients only): Vaginitis, amenorrhea, dysmenorrhea. Monotherapy in Adults with Epilepsy In addition to the adverse reactions reported above from the development of LAMICTAL XR, the following adverse reactions with an uncertain relationship to lamotrigine were reported during the clinical development of immediate-release lamotrigine for treatment of epilepsy in adults. These reactions occurred in >2% of patients receiving immediate-release lamotrigine and more frequently than in the placebo group. Body as a Whole: Chest pain. Digestive: Rectal hemorrhage, peptic ulcer. Metabolic and Nutritional: Weight decrease, peripheral edema. Nervous: Hypesthesia, libido increase, decreased reflexes. Respiratory: Epistaxis, dyspnea. Skin and Appendages: Contact dermatitis, dry skin, sweating. Special Senses: Vision abnormality. Urogenital (female patients only): Dysmenorrhea. Other Clinical Trial Experience Immediate-release lamotrigine has been administered to 6,694 individuals for whom complete adverse reaction data was captured during all clinical trials, only some of which were placebo controlled. Adverse reactions are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse reactions are defined as those occurring in at least 1/100 patients; infrequent adverse reactions are those occurring in 1/100 to 1/1,000 patients; rare adverse reactions are those occurring in fewer than 1/1,000 patients. Cardiovascular System: Infrequent: Hypertension, palpitations, postural hypotension, syncope, tachycardia, vasodilation. Dermatological: Infrequent: Acne, alopecia, hirsutism, maculopapular rash, urticaria. Rare: Leukoderma, multiforme erythema, petechial rash, pustular rash. Digestive System: Infrequent: Dysphagia, liver function tests abnormal, mouth ulceration. Rare: Gastrointestinal hemorrhage, hemorrhagic colitis, hepatitis, melena, stomach ulcer. Endocrine System: Rare: Goiter, hypothyroidism. Hematologic and Lymphatic System: Infrequent: Ecchymosis, leukopenia. Rare: Anemia, eosinophilia, fibrin decrease, fibrinogen decrease, iron deficiency anemia, leukocytosis, lymphocytosis, macrocytic anemia, petechia, thrombocytopenia. Metabolic and Nutritional Disorders: Infrequent: Aspartate transaminase increased. Rare: Alcohol intolerance, alkaline phosphatase increase, alanine transaminase increase, bilirubinemia, gamma glutamyl transpeptidase increase, hyperglycemia. Musculoskeletal System: Rare: Muscle atrophy, pathological fracture, tendinous contracture. Nervous System: Frequent: Confusion. Infrequent: Akathisia, apathy, aphasia, depersonalization, dysarthria, dyskinesia, euphoria, hallucinations, hostility, hyperkinesia, hypertonia, libido decreased, memory decrease, mind racing, movement disorder, myoclonus, panic attack, paranoid reaction, personality disorder, psychosis, stupor. Rare: Choreoathetosis, delirium, delusions, dysphoria, dystonia, extrapyramidal syndrome, hemiplegia, hyperalgesia, hyperesthesia, hypokinesia, hypotonia, manic depression reaction, neuralgia, paralysis, peripheral neuritis. Respiratory System: Rare: Hiccup, hyperventilation. Special Senses: Frequent: Amblyopia. Infrequent: Abnormality of accommodation, conjunctivitis, dry eyes, ear pain, photophobia, taste perversion, tinnitus. Rare: Deafness, lacrimation disorder, oscillopsia, parosmia, ptosis, strabismus, taste loss, uveitis, visual field defect. Urogenital System: Infrequent: Abnormal ejaculation, hematuria, impotence, menorrhagia, polyuria, urinary incontinence. Rare: Acute kidney failure, breast neoplasm, creatinine increase, female lactation, kidney failure, kidney pain, nocturia, urinary retention, urinary urgency. 6.3 Postmarketing Experience with Immediate-Release Lamotrigine The following adverse reactions have been identified during postapproval use of immediate-release lamotrigine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic Agranulocytosis, hemolytic anemia, lymphadenopathy not associated with hypersensitivity disorder, pseudolymphoma. Gastrointestinal Esophagitis. Hepatobiliary Tract and Pancreas Pancreatitis. Immunologic Hypogammaglobulinemia, lupus-like reaction, vasculitis. Lower Respiratory Apnea. Musculoskeletal Rhabdomyolysis has been observed in patients experiencing hypersensitivity reactions. Nervous System Aggression, exacerbation of Parkinsonian symptoms in patients with pre-existing Parkinson’s disease, tics. Non-site Specific Progressive immunosuppression. Renal and Urinary Disorders Tubulointerstitial nephritis (has been reported alone and in association with uveitis). Skin and subcutaneous tissue disorders Photosensitivity reaction

Warnings & Cautions for Lamictal

Life-threatening serious rash and/or rash-related death: Discontinue at the first sign of rash, unless the rash is clearly not drug related. ( Boxed Warning , 5.1 )
Hemophagocytic lymphohistiocytosis: Consider this diagnosis and evaluate patients immediately if they develop signs or symptoms of systemic inflammation. Discontinue LAMICTAL XR if an alternative etiology is not established. ( 5.2 )
Fatal or life-threatening hypersensitivity reaction: Multiorgan hypersensitivity reactions, also known as drug reaction with eosinophilia and systemic symptoms (DRESS), may be fatal or life threatening. Early signs may include rash, fever, and lymphadenopathy. These reactions may be associated with other organ involvement, such as hepatitis, hepatic failure, blood dyscrasias, or acute multiorgan failure. LAMICTAL XR should be discontinued if alternate etiology for this reaction is not found. ( 5.3 )
Cardiac rhythm and conduction abnormalities: Based on in vitro findings, LAMICTAL XR could cause serious arrhythmias and/or death in patients with certain underlying cardiac disorders or arrhythmias. Any expected or observed benefit of LAMICTAL XR in an individual patient with clinically important structural or functional heart disease must be carefully weighed against the risk for serious arrythmias and/or death for that patient. ( 5.4 )
Blood dyscrasias (e.g., neutropenia, thrombocytopenia, pancytopenia): May occur, either with or without an associated hypersensitivity syndrome. Monitor for signs of anemia, unexpected infection, or bleeding. ( 5.5 )
Suicidal behavior and ideation: Monitor for suicidal thoughts or behaviors. ( 5.6 )
Aseptic meningitis: Monitor for signs of meningitis. ( 5.7 )
Medication errors due to product name confusion: Strongly advise patients to visually inspect tablets to verify the received drug is correct. ( 5.8 , 16 , 17 ) 5.1 Serious Skin Rashes [see Boxed Warning] The risk of serious rash caused by treatment with LAMICTAL XR is not expected to differ from that with immediate-release lamotrigine [see Boxed Warning ] . However, the relatively limited treatment experience with LAMICTAL XR makes it difficult to characterize the frequency and risk of serious rashes caused by treatment with LAMICTAL XR. Pediatric Population The incidence of serious rash associated with hospitalization and discontinuation of immediate-release lamotrigine in a prospectively followed cohort of pediatric patients (aged 2 to 16 years) with epilepsy receiving adjunctive therapy with immediate-release lamotrigine was approximately 0.8% (16 of 1,983). When 14 of these cases were reviewed by 3 expert dermatologists, there was considerable disagreement as to their proper classification. To illustrate, 1 dermatologist considered none of the cases to be Stevens-Johnson syndrome; another assigned 7 of the 14 to this diagnosis. There was 1 rash-related death in this 1,983-patient cohort. Additionally, there have been rare cases of toxic epidermal necrolysis with and without permanent sequelae and/or death in U.S. and foreign postmarketing experience. There is evidence that the inclusion of valproate in a multidrug regimen increases the risk of serious, potentially life-threatening rash in pediatric patients. In pediatric patients who used valproate concomitantly, 1.2% (6 of 482) experienced a serious rash compared with 0.6% (6 of 952) patients not taking valproate. LAMICTAL XR is not approved in patients younger than 13 years. Adult Population Serious rash associated with hospitalization and discontinuation of immediate-release lamotrigine occurred in 0.3% (11 of 3,348) of adult patients who received immediate-release lamotrigine in premarketing clinical trials of epilepsy. In worldwide postmarketing experience, rare cases of rash-related death have been reported, but their numbers are too few to permit a precise estimate of the rate. Among the rashes leading to hospitalization were Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, and those associated with multiorgan hypersensitivity [see Warnings and Precautions ( 5.3 )] . Risk Factors Concomitant Use of Valproate There is evidence that the inclusion of valproate in a multidrug regimen increases the risk of serious, potentially life-threatening rash in adults. Specifically, of 584 patients administered immediate-release lamotrigine with valproate in epilepsy clinical trials, 6 (1%) were hospitalized in association with rash; in contrast, 4 (0.16%) of 2,398 clinical trial patients and volunteers administered immediate-release lamotrigine in the absence of valproate were hospitalized. Patients with History of Allergy or Rash to Other Antiepileptic Drugs The risk of rash may be increased in patients with a history of allergy or rash to other AEDs. Not Adhering to the Recommended Dosage The risk of rash is increased by both exceeding the recommended initial dose of LAMICTAL XR and exceeding the recommended dose escalation for LAMICTAL XR. Patients with Genetic Variant Human Leukocyte Antigen (HLA)‑B*1502 Allele Retrospective case-control studies in patients of certain Asian ancestry (e.g., Han Chinese and Thai) suggest that the HLA-B*1502 allele is associated with an increased risk (approximately 2‑3 times higher) of developing Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) in patients using lamotrigine. The risks and benefits of therapy should be weighed when considering use of LAMICTAL XR in patients known to be positive for HLA-B*1502. Application of HLA genotyping as a screening tool has important limitations and must never substitute for appropriate clinical vigilance and patient management. Many HLA‑B*1502‑positive patients treated with LAMICTAL XR will not develop SJS/TEN or other hypersensitivity reactions, and these reactions can still occur in HLA‑B*1502‑negative patients of any ethnicity. 5.2 Hemophagocytic Lymphohistiocytosis Hemophagocytic lymphohistiocytosis (HLH) has occurred in pediatric and adult patients taking LAMICTAL XR for various indications. HLH is a life-threatening syndrome of pathologic immune activation characterized by clinical signs and symptoms of extreme systemic inflammation. It is associated with high mortality rates if not recognized early and treated. Common findings include fever, hepatosplenomegaly, rash, lymphadenopathy, neurologic symptoms, cytopenias, high serum ferritin, hypertriglyceridemia, and liver function and coagulation abnormalities. In cases of HLH reported with LAMICTAL XR, patients have presented with signs of systemic inflammation (fever, rash, hepatosplenomegaly, and organ system dysfunction) and blood dyscrasias. Symptoms have been reported to occur within 8 to 24 days following the initiation of treatment. Patients who develop early manifestations of pathologic immune activation should be evaluated immediately, and a diagnosis of HLH should be considered. LAMICTAL XR should be discontinued if an alternative etiology for the signs or symptoms cannot be established. 5.3 Multiorgan Hypersensitivity Reactions and Organ Failure Multiorgan hypersensitivity reactions, also known as drug reaction with eosinophilia and systemic symptoms (DRESS), have occurred with lamotrigine. Some have been fatal or life threatening. DRESS typically, although not exclusively, presents with fever, rash, and/or lymphadenopathy in association with other organ system involvement, such as hepatitis, nephritis, hematologic abnormalities, myocarditis, or myositis, sometimes resembling an acute viral infection. Eosinophilia is often present. This disorder is variable in its expression and other organ systems not noted here may be involved. Fatalities associated with acute multiorgan failure and various degrees of hepatic failure have been reported in 2 of 3,796 adult patients and 4 of 2,435 pediatric patients who received lamotrigine in epilepsy clinical trials. Rare fatalities from multiorgan failure have also been reported in postmarketing use. Isolated liver failure without rash or involvement of other organs has also been reported with lamotrigine. It is important to note that early manifestations of hypersensitivity (e.g., fever, lymphadenopathy) may be present even though a rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. LAMICTAL XR should be discontinued if an alternative etiology for the signs or symptoms cannot be established. Prior to initiation of treatment with LAMICTAL XR, the patient should be instructed that a rash or other signs or symptoms of hypersensitivity (e.g., fever, lymphadenopathy) may herald a serious medical event and that the patient should report any such occurrence to a healthcare provider immediately. 5.4 Cardiac Rhythm and Conduction Abnormalities In vitro testing showed that LAMICTAL XR exhibits Class IB antiarrhythmic activity at therapeutically relevant concentrations [see Clinical Pharmacology ( 12.2 )] . Based on these in vitro findings, LAMICTAL XR could slow ventricular conduction (widen QRS) and induce proarrhythmia, which can lead to sudden death, in patients with clinically important structural or functional heart disease (i.e., patients with heart failure, valvular heart disease, congenital heart disease, conduction system disease, ventricular arrhythmias, cardiac channelopathies [e.g., Brugada syndrome], clinically important ischemic heart disease, or multiple risk factors for coronary artery disease). Any expected or observed benefit of LAMICTAL XR in an individual patient with clinically important structural or functional heart disease must be carefully weighed against the risks for serious arrythmias and/or death for that patient. Concomitant use of other sodium channel blockers may further increase the risk of proarrhythmia. 5.5 Blood Dyscrasias There have been reports of blood dyscrasias with immediate-release lamotrigine that may or may not be associated with multiorgan hypersensitivity (also known as DRESS) [see Warnings and Precautions ( 5.3 )] . These have included neutropenia, leukopenia, anemia, thrombocytopenia, pancytopenia, and, rarely, aplastic anemia and pure red cell aplasia. 5.6 Suicidal Behavior and Ideation AEDs, including LAMICTAL XR, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. Pooled analyses of 199 placebo-controlled clinical trials (monotherapy and adjunctive therapy) of 11 different AEDs showed that patients randomized to 1 of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI: 1.2, 2.7) of suicidal thinking or behavior compared with patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared with 0.24% among 16,029 placebo-treated patients, representing an increase of approximately 1 case of suicidal thinking or behavior for every 530 patients treated. There were 4 suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number of events is too small to allow any conclusion about drug effect on suicide. The increased risk of suicidal thoughts or behavior with AEDs was observed as early as 1 week after starting treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed. The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanism of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5 to 100 years) in the clinical trials analyzed. Table 3 shows absolute and relative risk by indication for all evaluated AEDs. Table 3. Risk by Indication for Antiepileptic Drugs in the Pooled Analysis Indication Placebo Patients with Events per 1,000 Patients Drug Patients with Events per 1,000 Patients Relative Risk: Incidence of Events in Drug Patients/ Incidence in Placebo Patients Risk Difference: Additional Drug Patients with Events per 1,000 Patients Epilepsy 1.0 3.4 3.5 2.4 Psychiatric 5.7 8.5 1.5 2.9 Other 1.0 1.8 1.9 0.9 Total 2.4 4.3 1.8 1.9 The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications. Anyone considering prescribing LAMICTAL XR or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated. Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, the emergence of suicidal thoughts or suicidal behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers. 5.7 Aseptic Meningitis Therapy with lamotrigine increases the risk of developing aseptic meningitis. Because of the potential for serious outcomes of untreated meningitis due to other causes, patients should also be evaluated for other causes of meningitis and treated as appropriate. Postmarketing cases of aseptic meningitis have been reported in pediatric and adult patients taking lamotrigine for various indications. Symptoms upon presentation have included headache, fever, nausea, vomiting, and nuchal rigidity. Rash, photophobia, myalgia, chills, altered consciousness, and somnolence were also noted in some cases. Symptoms have been reported to occur within 1 day to one and a half months following the initiation of treatment. In most cases, symptoms were reported to resolve after discontinuation of lamotrigine. Re-exposure resulted in a rapid return of symptoms (from within 30 minutes to 1 day following re-initiation of treatment) that were frequently more severe. Some of the patients treated with lamotrigine who developed aseptic meningitis had underlying diagnoses of systemic lupus erythematosus or other autoimmune diseases. Cerebrospinal fluid (CSF) analyzed at the time of clinical presentation in reported cases was characterized by a mild to moderate pleocytosis, normal glucose levels, and mild to moderate increase in protein. CSF white blood cell count differentials showed a predominance of neutrophils in a majority of the cases, although a predominance of lymphocytes was reported in approximately one third of the cases. Some patients also had new onset of signs and symptoms of involvement of other organs (predominantly hepatic and renal involvement), which may suggest that in these cases the aseptic meningitis observed was part of a hypersensitivity reaction [see Warnings and Precautions ( 5.3 )] . 5.8 Potential Medication Errors Medication errors involving LAMICTAL XR have occurred. In particular, the names LAMICTAL or lamotrigine can be confused with the names of other commonly used medications. Medication errors may also occur between the different formulations of LAMICTAL. To reduce the potential of medication errors, write and say LAMICTAL XR clearly. Depictions of the LAMICTAL XR extended-release tablets can be found in the Medication Guide. Each LAMICTAL XR tablet has a distinct color and white center, and is printed with “LAMICTAL XR” and the tablet strength. These distinctive features serve to identify the different presentations of the drug and thus may help reduce the risk of medication errors. LAMICTAL XR is supplied in round, unit-of-use bottles with orange caps containing 30 tablets. The label on the bottle includes a depiction of the tablets that further communicates to patients and pharmacists that the medication is LAMICTAL XR and the specific tablet strength included in the bottle. The unit-of-use bottle with a distinctive orange cap and distinctive bottle label features serves to identify the different presentations of the drug and thus may help to reduce the risk of medication errors. To avoid the medication error of using the wrong drug or formulation, patients should be strongly advised to visually inspect their tablets to verify that they are LAMICTAL XR each time they fill their prescription. 5.9 Concomitant Use with Estrogen-Containing Products, Including Oral Contraceptives Some estrogen-containing oral contraceptives have been shown to decrease serum concentrations of lamotrigine [see Clinical Pharmacology ( 12.3 )] . Dosage adjustments will be necessary in most patients who start or stop estrogen-containing oral contraceptives while taking LAMICTAL XR [see Dosage and Administration ( 2.1 )] . During the week of inactive hormone preparation (pill-free week) of oral contraceptive therapy, plasma lamotrigine levels are expected to rise, as much as doubling at the end of the week. Adverse reactions consistent with elevated levels of lamotrigine, such as dizziness, ataxia, and diplopia, could occur. Other oral contraceptive and other estrogen-containing therapies (such as HRT) have not been studied, though they may similarly affect lamotrigine pharmacokinetic parameters. 5.10 Withdrawal Seizures As with other AEDs, LAMICTAL XR should not be abruptly discontinued. In patients with epilepsy there is a possibility of increasing seizure frequency. Unless safety concerns require a more rapid withdrawal, the dose of LAMICTAL XR should be tapered over a period of at least 2 weeks (approximately 50% reduction per week) [see Dosage and Administration ( 2.1 )] . 5.11 Status Epilepticus Valid estimates of the incidence of treatment-emergent status epilepticus among patients treated with immediate-release lamotrigine are difficult to obtain because reporters participating in clinical trials did not all employ identical rules for identifying cases. At a minimum, 7 of 2,343 adult patients had episodes that could unequivocally be described as status epilepticus. In addition, a number of reports of variably defined episodes of seizure exacerbation (e.g., seizure clusters, seizure flurries) were made. 5.12 Addition of LAMICTAL XR to a Multidrug Regimen that Includes Valproate Because valproate reduces the clearance of lamotrigine, the dosage of lamotrigine in the presence of valproate is less than half of that required in its absence [see Dosage and Administration ( 2.1 , 2.2 ), Drug Interactions ( 7 )] . 5.13 Binding in the Eye and Other Melanin-Containing Tissues Because lamotrigine binds to melanin, it could accumulate in melanin-rich tissues over time. This raises the possibility that lamotrigine may cause toxicity in these tissues after extended use. Although ophthalmological testing was performed in 1 controlled clinical trial, the testing was inadequate to exclude subtle effects or injury occurring after long-term exposure. Moreover, the capacity of available tests to detect potentially adverse consequences, if any, of lamotrigine’s binding to melanin is unknown. Accordingly, although there are no specific recommendations for periodic ophthalmological monitoring, prescribers should be aware of the possibility of long-term ophthalmologic effects. 5.14 Laboratory Tests False-Positive Drug Test Results Lamotrigine has been reported to interfere with the assay used in some rapid urine drug screens, which can result in false-positive readings, particularly for phencyclidine (PCP). A more specific analytical method should be used to confirm a positive result. Plasma Concentrations of Lamotrigine The value of monitoring plasma concentrations of lamotrigine in patients treated with LAMICTAL XR has not been established. Because of the possible pharmacokinetic interactions between lamotrigine and other drugs, including AEDs (see Table 6 ), monitoring of the plasma levels of lamotrigine and concomitant drugs may be indicated, particularly during dosage adjustments. In general, clinical judgment should be exercised regarding monitoring of plasma levels of lamotrigine and other drugs and whether or not dosage adjustments are necessary. Effect on Leukocytes Treatment with LAMICTAL XR caused an increased incidence of subnormal (below the reference range) values in some hematology analytes (e.g., total white blood cells, monocytes). The treatment effect (LAMICTAL XR % - Placebo %) incidence of subnormal counts was 3% for total white blood cells and 4% for monocytes.

Drug Interactions with Lamictal

Significant drug interactions with lamotrigine are summarized in this section. Additional details of these drug interaction studies, which were conducted using immediate-release lamotrigine, are provided in the Clinical Pharmacology section [see Clinical Pharmacology ( 12.3 )] . Uridine 5´-diphospho-glucuronyl transferases (UGT) have been identified as the enzymes responsible for metabolism of lamotrigine. Drugs that induce or inhibit glucuronidation may, therefore, affect the apparent clearance of lamotrigine. Strong or moderate inducers of the cytochrome P450 3A4 (CYP3A4) enzyme, which are also known to induce UGT, may also enhance the metabolism of lamotrigine. Those drugs that have been demonstrated to have a clinically significant impact on lamotrigine metabolism are outlined in Table 13. Specific dosing guidance for these drugs is provided in the Dosage and Administration section, and, for women taking estrogen-containing products, including oral contraceptives, in the Warnings and Precautions section [see Dosage and Administration ( 2.1 ), Warnings and Precautions, ( 5.9 )] . Table 5. Established and Other Potentially Significant Drug Interactions ↓ = Decreased (induces lamotrigine glucuronidation). ↑ = Increased (inhibits lamotrigine glucuronidation). ? = Conflicting data. Concomitant Drug Effect on Concentration of Lamotrigine or Concomitant Drug Clinical Comment Estrogen-containing oral contraceptive preparations containing 30 mcg ethinylestradiol and 150 mcg levonorgestrel ↓ lamotrigine Decreased lamotrigine concentrations approximately 50%. ↓ levonorgestrel Decrease in levonorgestrel component by 19%. Carbamazepine and carbamazepine epoxide ↓ lamotrigine Addition of carbamazepine decreases lamotrigine concentration approximately 40%. ? carbamazepine epoxide May increase carbamazepine epoxide levels. Lopinavir/ritonavir ↓ lamotrigine Decreased lamotrigine concentration approximately 50%. Atazanavir/ritonavir ↓ lamotrigine Decreased lamotrigine AUC approximately 32%. Phenobarbital/primidone ↓ lamotrigine Decreased lamotrigine concentration approximately 40%. Phenytoin ↓ lamotrigine Decreased lamotrigine concentration approximately 40%. Rifampin ↓ lamotrigine Decreased lamotrigine AUC approximately 40%. Valproate ↑ lamotrigine Increased lamotrigine concentrations slightly more than 2-fold. ? valproate There are conflicting study results regarding effect of lamotrigine on valproate concentrations: 1) a mean 25% decrease in valproate concentrations in healthy volunteers, 2) no change in valproate concentrations in controlled clinical trials in patients with epilepsy. Effect of LAMICTAL XR on Organic Cationic Transporter 2 Substrates Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins [see Clinical Pharmacology ( 12.3 )] . This may result in increased plasma levels of certain drugs that are substantially excreted via this route. Coadministration of LAMICTAL XR with OCT2 substrates with a narrow therapeutic index (e.g., dofetilide) is not recommended.
Valproate increases lamotrigine concentrations more than 2-fold. ( 7 , 12.3 )
Carbamazepine, phenytoin, phenobarbital, primidone, and rifampin decrease lamotrigine concentrations by approximately 40%. ( 7 , 12.3 )
Estrogen-containing oral contraceptives decrease lamotrigine concentrations by approximately 50%. ( 7 , 12.3 )
Protease inhibitors lopinavir/ritonavir and atazanavir/lopinavir decrease lamotrigine exposure by approximately 50% and 32%, respectively. ( 7 , 12.3 )
Coadministration with organic cationic transporter 2 (OCT2) substrates with narrow therapeutic index is not recommended ( 7 , 12.3 )

Pregnancy Safety for Lamictal

Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, including LAMICTAL XR, during pregnancy. Encourage women who are taking LAMICTAL XR during pregnancy to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling 1-888-233-2334 or visiting http://www.aedpregnancyregistry.org/. Risk Summary Data from several prospective pregnancy exposure registries and epidemiological studies of pregnant women have not detected an increased frequency of major congenital malformations or a consistent pattern of malformations among women exposed to lamotrigine compared with the general population (see Data). In animal studies, administration of lamotrigine during pregnancy resulted in developmental toxicity (increased mortality, decreased body weight, increased structural variation, neurobehavioral abnormalities) at doses lower than those administered clinically. Lamotrigine decreased fetal folate concentrations in rats, an effect known to be associated with adverse pregnancy outcomes in animals and humans (see Data). In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations Disease-associated Maternal and/or Embryofetal Risk Epilepsy, with or without exposure to antiepileptic drugs, has been associated with several adverse outcomes during pregnancy, including preeclampsia, preterm labor, antepartum and postpartum hemorrhage, placental abruption, poor fetal growth, prematurity, fetal death, and maternal mortality. The risk of maternal or fetal injury may be greatest for patients with untreated or poorly controlled convulsive seizures. Women with epilepsy who become pregnant should not abruptly discontinue antiepileptic drugs, including LAMICTAL XR, due to the risk of status epilepticus or severe seizures, which may be life-threatening.

Dose Adjustments During Pregnancy and the Postpartum Period As with other AEDs, physiological changes during pregnancy may affect lamotrigine concentrations and/or therapeutic effect. There have been reports of decreased lamotrigine concentrations during pregnancy and restoration of pre-pregnancy concentrations after delivery. Dose adjustments may be necessary to maintain clinical response.

Data Human Data: Data from several international pregnancy registries have not shown an increased risk for malformations overall. The International Lamotrigine Pregnancy Registry reported major congenital malformations in 2.2% (95% CI: 1.6%, 3.1%) of 1,558 infants exposed to lamotrigine monotherapy in the first trimester of pregnancy. The NAAED Pregnancy Registry reported major congenital malformations among 2.0% of 1,562 infants exposed to lamotrigine monotherapy in the first trimester.

EURAP, a large international pregnancy registry focused outside of North America, reported major birth defects in 2.9% (95% CI: 2.3%, 3.7%) of 2,514 exposures to lamotrigine monotherapy in the first trimester. The frequency of major congenital malformations was similar to estimates from the general population. The NAAED Pregnancy Registry observed an increased risk of isolated oral clefts: among 2,200 infants exposed to lamotrigine early in pregnancy, the risk of oral clefts was 3.2 per 1,000 (95% CI: 1.4, 6.3), a 3-fold increased risk versus unexposed healthy controls.

This finding has not been observed in other large international pregnancy registries. Furthermore, a case-control study based on 21 congenital anomaly registries covering over 10 million births in Europe reported an adjusted odds ratio for isolated oral clefts with lamotrigine exposure of 1.45 (95% CI: 0.8, 2.63). Several meta-analyses have not reported an increased risk of major congenital malformations following lamotrigine exposure in pregnancy compared with healthy and disease-matched controls. No patterns of specific malformation types were observed.

The same meta-analyses evaluated the risk of additional maternal and infant outcomes including fetal death, stillbirth, preterm birth, small for gestational age, and neurodevelopmental delay. Although there are no data suggesting an increased risk of these outcomes with lamotrigine monotherapy exposure, differences in outcome definition, ascertainment methods, and comparator groups limit the conclusions that can be drawn. Animal Data: When lamotrigine was administered to pregnant mice, rats, or rabbits during the period of organogenesis (oral doses of up to 125, 25, and 30 mg/kg, respectively), reduced fetal body weight and increased incidences of fetal skeletal variations were seen in mice and rats at doses that were also maternally toxic.

The no-effect doses for embryofetal developmental toxicity in mice, rats, and rabbits (75, 6.25, and 30 mg/kg, respectively) are similar to (mice and rabbits) or less than (rats) the human dose of 400 mg/day on a body surface area (mg/m 2 ) basis. In a study in which pregnant rats were administered lamotrigine (oral doses of 0, 5, or 25 mg/kg) during the period of organogenesis and offspring were evaluated postnatally, neurobehavioral abnormalities were observed in exposed offspring at both doses. The lowest effect dose for developmental neurotoxicity in rats is less than the human dose of 400 mg/day on a mg/m 2 basis.

Maternal toxicity was observed at the higher dose tested. When pregnant rats were administered lamotrigine (oral doses of 0, 5, 10, or 20 mg/kg) during the latter part of gestation and throughout lactation, increased offspring mortality (including stillbirths) was seen at all doses. The lowest effect dose for pre- and post-natal developmental toxicity in rats is less than the human dose of 400 mg/day on a mg/m 2 basis.

Maternal toxicity was observed at the 2 highest doses tested. When administered to pregnant rats, lamotrigine decreased fetal folate concentrations at doses greater than or equal to 5 mg/kg/day, which is less than the human dose of 400 mg/day on a mg/m 2 basis.

Pediatric Use of Lamictal

Pediatric Use LAMICTAL XR is indicated as adjunctive therapy for PGTC and partial-onset seizures with or without secondary generalization in patients aged 13 years and older. Safety and effectiveness of LAMICTAL XR for any use in patients younger than 13 years have not been established. Immediate-release lamotrigine is indicated as adjunctive therapy in patients aged 2 years and older for partial-onset seizures, the generalized seizures of Lennox-Gastaut syndrome, and PGTC seizures.

Safety and efficacy of immediate-release lamotrigine used as adjunctive treatment for partial-onset seizures were not demonstrated in a small, randomized, double-blind, placebo-controlled withdrawal trial in very young pediatric patients (aged 1 to 24 months). Immediate-release lamotrigine was associated with an increased risk for infectious adverse reactions (lamotrigine 37%, placebo 5%), and respiratory adverse reactions (lamotrigine 26%, placebo 5%). Infectious adverse reactions included bronchiolitis, bronchitis, ear infection, eye infection, otitis externa, pharyngitis, urinary tract infection, and viral infection. Respiratory adverse reactions included nasal congestion, cough, and apnea. Juvenile Animal Data In a juvenile animal study in which lamotrigine (oral doses of 0, 5, 15, or 30 mg/kg) was administered to young rats from postnatal day 7 to 62, decreased viability and growth were seen at the highest dose tested and long-term neurobehavioral abnormalities (decreased locomotor activity, increased reactivity, and learning deficits in animals tested as adults) were observed at the 2 highest doses.

The no-effect dose for adverse developmental effects in juvenile animals is less than the human dose of 400 mg/day on a mg/m 2 basis.

Contraindications for Lamictal

is contraindicated in patients who have demonstrated hypersensitivity (e.g., rash, angioedema, acute urticaria, extensive pruritus, mucosal ulceration) to the drug or its ingredients . Hypersensitivity to the drug or its ingredients. ( Boxed Warning, 4 )

Overdosage Information for Lamictal

Human Overdose Experience Overdoses involving quantities up to 15 g have been

reported for immediate-release lamotrigine, some of which have been fatal. Overdose has resulted in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma, and intraventricular conduction delay.

Management of Overdose

There are no specific antidotes for lamotrigine. Following a suspected overdose, hospitalization of the patient is advised. General supportive care is indicated, including frequent monitoring of vital signs and close observation of the patient.

If indicated, emesis should be induced; usual precautions should be taken to protect the airway. It is uncertain whether hemodialysis is an effective means of removing lamotrigine from the blood. In 6 renal failure patients, about 20% of the amount of lamotrigine in the body was removed by hemodialysis during a 4-hour session.

A Poison Control Center should be contacted for information on the management of overdosage of LAMICTAL XR.

Clinical Studies of Lamictal

Adjunctive Therapy for Primary Generalized Tonic-Clonic Seizures

The effectiveness of LAMICTAL XR as adjunctive therapy in subjects with PGTC seizures was established in a 19-week, international, multicenter, double-blind, randomized, placebo-controlled trial in 143 patients aged 13 years and older (n = 70 on LAMICTAL XR, n = 73 on placebo). Patients with at least 3 PGTC seizures during an 8-week baseline phase were randomized to 19 weeks of treatment with LAMICTAL XR or placebo added to their current AED regimen of up to 2 drugs. Patients were dosed on a fixed-dose regimen, with target doses ranging from 200 to 500 mg/day of LAMICTAL XR based on concomitant AEDs (target dose = 200 mg for valproate, 300 mg for AEDs not altering plasma lamotrigine levels, and 500 mg for enzyme-inducing AEDs). The primary efficacy endpoint was percent change from baseline in PGTC seizure frequency during the double-blind treatment phase. For the intent-to-treat population, the median percent reduction in PGTC seizure frequency was 75% in patients treated with LAMICTAL XR and 32% in patients treated with placebo, a difference that was statistically significant, defined as a 2-sided P value < 0.05. Figure 1 presents the percentage of patients (X-axis) with a percent reduction in PGTC seizure frequency (responder rate) from baseline through the entire treatment period at least as great as that represented on the Y-axis.

A positive value on the Y-axis indicates an improvement from baseline (i.e., a decrease in seizure frequency), while a negative value indicates a worsening from baseline (i.e., an increase in seizure frequency). Thus, in a display of this type, a curve for an effective treatment is shifted to the left of the curve for placebo. The proportion of patients achieving any particular level of reduction in PGTC seizure frequency was consistently higher for the group treated with LAMICTAL XR compared with the placebo group. For example, 70% of patients randomized to LAMICTAL XR experienced a 50% or greater reduction in PGTC seizure frequency, compared with 32% of patients randomized to placebo.

Patients with an increase in seizure frequency >100% are represented on the Y-axis as ≥-100%. Figure 1. Proportion of Patients by Responder Rate for LAMICTAL XR and Placebo Group (Primary Generalized Tonic-Clonic Seizures Study) Figure 1. Proportion of Patients by Responder Rate for LAMICTAL XR and Placebo Group (Primary Generalized Tonic-Clonic Seizures Study)

Adjunctive Therapy for Partial-Onset Seizures

The effectiveness of immediate-release lamotrigine as adjunctive therapy was initially established in 3 pivotal, multicenter, placebo-controlled, double-blind clinical trials in 355 adults with refractory partial-onset seizures. The effectiveness of LAMICTAL XR as adjunctive therapy in partial-onset seizures, with or without secondary generalization, was established in a 19-week, multicenter, double-blind, placebo-controlled trial in 236 patients aged 13 years and older (approximately 93% of patients were aged 16 to 65 years). Approximately 36% were from the U.S. and approximately 64% were from other countries including Argentina, Brazil, Chile, Germany, India, Korea, Russian Federation, and Ukraine. Patients with at least 8 partial-onset seizures during an 8-week prospective baseline phase (or 4-week prospective baseline coupled with a 4-week historical baseline documented with seizure diary data) were randomized to treatment with LAMICTAL XR (n = 116) or placebo (n = 120) added to their current regimen of 1 or 2 AEDs.

Approximately half of the patients were taking 2 concomitant AEDs at baseline. Target doses ranged from 200 to 500 mg/day of LAMICTAL XR based on concomitant AED (target dose = 200 mg for valproate, 300 mg for AEDs not altering plasma lamotrigine, and 500 mg for enzyme-inducing AEDs). The median partial seizure frequency per week at baseline was 2.3 for LAMICTAL XR and 2.1 for placebo. The primary endpoint was the median percent change from baseline in partial-onset seizure frequency during the entire double-blind treatment phase.

The median percent reductions in weekly partial-onset seizures were 47% in patients treated with LAMICTAL XR and 25% on placebo, a difference that was statistically significant, defined as a 2-sided P value ≤ 0.05. Figure 2 presents the percentage of patients (X-axis) with a percent reduction in partial-onset seizure frequency (responder rate) from baseline through the entire treatment period at least as great as that represented on the Y-axis. The proportion of patients achieving any particular level of reduction in partial-onset seizure frequency was consistently higher for the group treated with LAMICTAL XR compared with the placebo group. For example, 44% of patients randomized to LAMICTAL XR experienced a 50% or greater reduction in partial-onset seizure frequency compared with 21% of patients randomized to placebo.

Figure 2. Proportion of Patients by Responder Rate for LAMICTAL XR and Placebo Group (Partial-Onset Seizure Study) Figure 2. Proportion of Patients by Responder Rate for LAMICTAL XR and Placebo Group (Partial-Onset Seizure Study)

Conversion to Monotherapy for Partial-Onset Seizures

The effectiveness of LAMICTAL XR as monotherapy for partial-onset seizures was established in a historical control trial in 223 adults with partial-onset seizures. The historical control methodology is described in a publication by French, et al. . Briefly, in this study, patients were randomized to ultimately receive either LAMICTAL XR 300 or 250 mg once a day, and their responses were compared with those of a historical control group. The historical control consisted of a pooled analysis of the control groups from 8 studies of similar design, which utilized a subtherapeutic dose of an AED as a comparator.

Statistical superiority to the historical control was considered to be demonstrated if the upper 95% confidence interval for the proportion of patients meeting escape criteria in patients receiving LAMICTAL XR remained below the lower 95% prediction interval of 65.3% derived from the historical control data. In this study, patients aged 13 years and older experienced at least 4 partial-onset seizures during an 8-week baseline period with at least 1 seizure occurring during each of 2 consecutive 4-week periods while receiving valproate or a non–enzyme-inducing AED. LAMICTAL XR was added to either valproate or a non–enzyme-inducing AED over a 6- to 7-week period followed by the gradual withdrawal of the background AED. Patients were then continued on monotherapy with LAMICTAL XR for 12 weeks. The escape criteria were 1 or more of the following: doubling of average monthly seizure count during any 28 consecutive days, doubling of highest consecutive 2-day seizure frequency during the entire treatment phase, emergence of a new seizure type compared with baseline clinically significant prolongation of generalized tonic-clonic seizures or worsening of seizure considered by the investigator to require intervention.

These criteria were similar to those in the 8 controlled trials from which the historical control group was constituted. The upper 95% confidence limits of the proportion of subjects meeting escape criteria (40.2% at 300 mg/day and 44.5% at 250 mg/day) were below the threshold of 65.3% derived from the historical control data. Although the study population was not fully comparable with the historical control population and the study was not fully blinded, numerous sensitivity analyses supported the primary results.

Efficacy was further supported by the established effectiveness of the immediate-release formulation as monotherapy.

Drug information sourced from the FDA. This content is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before making any medication decisions.

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