Tuxarin Drug Information

Important Dosage and

Administration Instructions Administer TUXARIN ER by the oral route only. Advise patients not to increase the dose or dosing frequency of TUXARIN ER because serious adverse events such as respiratory depression may occur with overdosage. The dosage of TUXARIN ER should not be increased if cough fails to respond; an unresponsive cough should be reevaluated for possible underlying pathology.

Recommended Dosage Adults 18 years of age and older: one tablet every

12 hours as needed, not to exceed 2 tablets in 24 hours.

Monitoring, Maintenance, and Discontinuation of Therapy Prescribe

TUXARIN ER for the shortest duration that is consistent with individual patient treatment goals Monitor patients closely for respiratory depression, especially within the first 24-72 hours of initiating therapy . Reevaluate patients with unresponsive cough in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease. If a patient requires a refill, reevaluate the cause of the cough and assess the need for continued treatment with TUXARIN ER, the relative incidence of adverse reactions, and the development of addiction, abuse, or misuse. Do not abruptly discontinue TUXARIN ER in a physically-dependent patient.

When a patient who has been taking TUXARIN ER regularly and may be physically dependent no longer requires therapy with TUXARIN ER, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both.

The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, abuse, and misuse Life-threatening respiratory depression Ultra-rapid metabolism of codeine and other risk factors for life-threatening respiratory depression in children Accidental overdose and death due to medication errors Decreased mental alertness with impaired mental and/or physical abilities Interactions with benzodiazepines and other CNS depressants Paralytic ileus, gastrointestinal adverse reactions Increased intracranial pressure Obscured clinical course in patients with head injuries Seizures Interactions with MAOI Severe hypotension Neonatal Opioid Withdrawal Syndrome Adrenal insufficiency The following adverse reactions have been identified during clinical studies, or during post-approval use of codeine and/or chlorpheniramine. Because these reactions may be 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. The most common adverse reactions to TUXARIN ER include: Sedation (somnolence, mental clouding, lethargy), impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, constipation, shortness of breath, and sweating.

Other reactions include: Anaphylaxis : Anaphylaxis has been reported with codeine, one of the ingredients in TUXARIN ER. Body as a whole : Coma, death, fatigue, falling injuries, lethargy. Cardiovascular : Peripheral edema, increased blood pressure, decreased blood pressure, tachycardia, chest pain, palpitation, syncope, orthostatic hypotension, prolonged QT interval, hot flush. Central Nervous System : Ataxia, facial dyskinesia, insomnia, increased intracranial pressure, migraine, seizure, tremor, tinnitus, vertigo.

Dermatologic : Flushing, hyperhidrosis, pruritus, rash. Endocrine/Metabolic : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.

Cases of androgen deficiency have occurred with chronic use of opioids. Gastrointestinal : Abdominal pain, bowel obstruction, decreased appetite, diarrhea, difficulty swallowing, GERD, indigestion, pancreatitis, paralytic ileus, biliary tract spasm (spasm of the sphincter of Oddi). Genitourinary : Urinary tract infection, ureteral spasm, spasm of vesicle sphincters, urinary retention. Hematologic : Agranulocytosis, aplastic anemia, and thrombocytopenia have been reported.

Laboratory: Increases in serum amylase. Musculoskeletal : Arthralgia, backache, muscle spasm. Ophthalmic : Blurred vision, diplopia, miosis (constricted pupils), visual disturbances.

Psychiatric : Agitation, anxiety, confusion, fear, dysphoria, depression, hallucinations. Reproductive : Hypogonadism, infertility. Respiratory : Bronchitis, cough, dry nose, dry throat, dyspnea, nasal congestion, nasopharyngitis, respiratory depression, sinusitis, thickening of bronchial secretions, tightness of chest and wheezing, upper respiratory tract infection.

Other : Drug abuse, drug dependence, opioid withdrawal syndrome. Hypoglycemia: Cases of hypoglycemia have been reported in patients taking opioids. Most reports were in patients with at least one predisposing risk factor (e.g., diabetes). Common adverse reactions of TUXARIN ER include: Sedation (somnolence, mental clouding, lethargy), impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, constipation, shortness of breath, and sweating.

To report SUSPECTED ADVERSE REACTIONS, contact MainPointe Pharmaceuticals, LLC at 502-709-7544 or go to mainpointepharmaceuticals.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Inhibitors of

CYP3A4 The concomitant use of TUXARIN ER with CYP3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), or protease inhibitors (e.g., ritonavir), may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of TUXARIN ER is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, it may result in lower codeine levels, greater norcodeine levels, and less metabolism via CYP2D6 with resultant lower morphine levels, resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to codeine. Avoid the use of TUXARIN ER while taking a CYP3A4 inhibitor.

If concomitant use is necessary, monitor patients for respiratory depression and sedation at frequent intervals.

CYP3A4 Inducers

The concomitant use of TUXARIN ER and CYP3A4 inducers, such as rifampin, carbamazepine, or phenytoin, can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels, resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. After stopping a CYP3A4 inducer, as the effects of the inducer decline, codeine plasma concentrations may increase with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. Avoid the use of TUXARIN ER in patients who are taking CYP3A4 inducers.

If concomitant use of a CYP3A4 inducer is necessary, follow the patient for reduced efficacy.

Phenytoin Adverse event reports in the literature suggest a possible drug interaction

involving increased serum phenytoin levels and phenytoin toxicity when chlorpheniramine and phenytoin are co-administered. The exact mechanism for this interaction is not known, however it is believed that chlorpheniramine may inhibit the hepatic metabolism of phenytoin. Avoid the use of TUXARIN ER while taking phenytoin.

Inhibitors of

CYP2D6 Codeine is metabolized by CYP2D6 to form morphine. The concomitant use of TUXARIN ER and CYP2D6 inhibitors, such as paroxetine, fluoxetine, bupropion, or quinidine, can increase the plasma concentration of codeine, but can decrease the plasma concentration of active metabolite morphine, which could result in reduced efficacy. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the codeine plasma concentration will decrease but the active metabolite morphine plasma concentration will increase, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression.

Avoid the use of TUXARIN ER in patients who are taking inhibitors of CYP2D6.

Benzodiazepines and Other

CNS Depressants Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Avoid the use of TUXARIN ER in patients who are taking benzodiazepines or other CNS depressants. .

Serotonergic Drugs

The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation. Discontinue TUXARIN ER if serotonin syndrome is suspected.

Monoamine Oxidase Inhibitors (MAOIs)

TUXARIN ER is contraindicated in patients who are taking MAOIs (i.e., certain drugs used for depression, psychiatric or emotional conditions, or Parkinson's disease) or have taken MAOIs within 14 days. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma) .

Muscle Relaxants Codeine may enhance the neuromuscular blocking action of skeletal muscle

relaxants and produce an increased degree of respiratory depression. Avoid the use of TUXARIN ER in patients taking muscle relaxants. If concomitant use is necessary, monitor patients for signs of respiratory depression that may be greater than otherwise expected.

Diuretics Opioids can reduce the efficacy of diuretics by inducing the release

of antidiuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. 7.10 Anticholinergic Drugs The concomitant use of anticholinergic drugs with TUXARIN ER may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of urinary retention or reduced gastric motility when TUXARIN ER is used concomitantly with anticholinergic drugs.

Additive adverse effects resulting from cholinergic blockade (e.g., xerostomia, blurred vision, or constipation) may occur when anticholinergic drugs are administered with chlorpheniramine.

Pregnancy Risk Summary TUXARIN ER is not recommended for use in pregnant women, including during or immediately prior to labor. Prolonged use of opioids during pregnancy may cause neonatal opioid withdrawal syndrome. There are no available data with TUXARIN ER use in pregnant women to inform a drug-associated risk for adverse developmental outcomes.

Published studies with codeine have reported inconsistent findings and have important methodological limitations ( see Data ). There are reports of respiratory depression when codeine is used during labor and delivery (see Clinical Considerations ). Reproductive toxicity studies have not been conducted with TUXARIN ER; however, studies are available with individual active ingredients ( see Data ). In animal reproduction studies, codeine administered by the oral route to pregnant rats during the period of organogenesis increased resorptions and decreased fetal weights at a dose approximately 15 times the maximum recommended human dose (MRHD) in the presence of maternal toxicity ( see Data ). Chlorpheniramine administered by the oral route to mice throughout pregnancy was embryolethal at a dose approximately 9 times the MRHD and decreased postnatal survival when dosing was continued after parturition. Chlorpheniramine administered by the oral route to male and female rats prior to mating produced embryolethality at a dose approximately 9 times the MRHD ( see Data ). Based on the animal data, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. 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 Fetal/Neonatal Adverse Reactions Prolonged use of opioid analgesics during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth.

Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly.

Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. Opioids, including TUXARIN ER, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions.

However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioids during labor for signs of excess sedation and respiratory depression. Data Human Data No new primary pharmacodynamic studies were conducted.

Codeine is a well-established antitussive and chlorpheniramine maleate is a recognized antihistamine. Both drugs have been used at these strengths in combination for several years. Codeine Published data from case-control and observational studies on codeine use during pregnancy are inconsistent in their findings.

Some studies of codeine exposure showed an increased risk of overall congenital malformations while others did not. An increased risk of specific malformations with codeine exposure such as respiratory malformations, spina bifida and congenital heart defects were reported in some studies. Most of the studies, both positive and negative, were limited by small sample size, recall bias and lack of information regarding dose and timing of exposure.

Chlorpheniramine The majority of studies examining the use of chlorpheniramine in pregnancy did not find an association with an increased risk of congenital anomalies. In the few studies reporting an association, there was no consistent pattern of malformations noted. Animal Data Reproductive toxicity studies have not been conducted with TUXARIN ER; however, studies are available with individual active ingredients.

Codeine In an embryofetal development study in pregnant rats dosed throughout the period of organogenesis, codeine increased resorptions and decreased fetal weights at a dose approximately 15 times the MRHD (on a mg/m 2 basis with a maternal oral dose of 120 mg/kg/day); however, these effects occurred in the presence of maternal toxicity. In embryofetal development studies with pregnant rabbits and mice dosed throughout the period of organogenesis, codeine produced no adverse developmental effects at doses approximately 7 and 35 times, respectively, the MRHD (on a mg/m 2 basis with maternal oral doses of 30 mg/kg/day in rabbits and 600 mg/kg/day in mice). Chlorpheniramine In embryofetal development studies with pregnant rats and rabbits dosed throughout the period of organogenesis, chlorpheniramine produced no adverse developmental effects at oral doses up to approximately 35 and 45 times, respectively, the MRHD on a mg/m 2 basis. However, in a reproduction study with pregnant mice dosed throughout pregnancy, chlorpheniramine produced embryolethality at a dose approximately 9 times the MRHD (on a mg/m 2 basis with a maternal oral dose of 20 mg/kg/day) and decreased postnatal survival when dosing was continued after parturition.

In a fertility and reproduction study with male and female rats dosed prior to mating, chlorpheniramine produced embryolethality at a dose approximately 9 times the MRHD (on a mg/m 2 basis with an oral parental dose of 10 mg/kg/day).

Pediatric Use TUXARIN ER is not indicated for use in patients younger than 18 years of age because the benefits of symptomatic treatment of cough associated with allergies or the common cold do not outweigh the risks for use of codeine in these patients. Life-threatening respiratory depression and death have occurred in children who received codeine. In most of the reported cases, these events followed tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of codeine (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6 or high morphine concentrations). Children with sleep apnea may be particularly sensitive to the respiratory depressant effects of codeine.

Because of the risk of life-threatening respiratory depression and death: TUXARIN ER is contraindicated in all children younger than 12 years of age . TUXARIN ER is contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy . Avoid the use of TUXARIN ER in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression. .

is contraindicated for: All children younger than 12 years of age. Postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy. TUXARIN ER is also contraindicated in patients with: Significant respiratory depression Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment.

Known or suspected gastrointestinal obstruction, including paralytic ileus. Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within 14 days. Hypersensitivity to codeine, chlorpheniramine, or any of the inactive ingredients in TUXARIN ER. Persons known to be hypersensitive to certain other opioids may exhibit cross-reactivity to codeine.

Children younger than 12 years of age Significant respiratory depression. Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment. Known or suspected gastrointestinal obstruction, including paralytic ileus.

Concurrent use of monoamine oxidase inhibitor (MAOI) therapy or within the last 14 days. Hypersensitivity to codeine or other opiates, chlorpheniramine, or any of the inactive ingredients in TUXARIN ER.

Clinical Presentation Codeine Acute overdose with codeine is characterized by respiratory depression (a decrease in respiratory rate and/or tidal volume, Cheyne-Stokes respiration, cyanosis), extreme somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, partial or complete airway obstruction, atypical snoring, hypotension, hypoglycemia, circulatory collapse, cardiac arrest, and death. Codeine may cause miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origin may produce similar findings). Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations.

Chlorpheniramine Signs and symptoms of chlorpheniramine overdosage may vary from central nervous system depression to stimulation. Central toxic effects are characterized by agitation, anxiety, delirium, disorientation, hallucinations, hyperactivity, sedation, and seizures. Severe overdosage may produce coma, medullary paralysis, and death.

Peripheral toxicity includes hypertension, tachycardia, dysrhythmias, vasodilation, hyperpyrexia, mydriasis, urinary retention, and diminished gastrointestinal motility. Atropine-like signs and symptoms (dry mouth, fixed dilated pupils, flushing, tachycardia, hallucinations, gastrointestinal symptoms, convulsions, urinary retention, cardiac arrhythmias and coma) may be observed. Impaired secretion from sweat glands following toxic doses of drugs with anticholinergic side effects may predispose to hyperthermia.

Toxic psychosis, a possible class effect from overdose of sedating antihistamines, has been reported. Treatment of Overdose Treatment of overdosage is driven by the overall clinical presentation, and consists of discontinuation of TUXARIN ER together with institution of appropriate therapy. Give primary attention to the reestablishment of adequate respiratory exchange through provision of a patent and protected airway and the institution of assisted or controlled ventilation.

Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life-support techniques. Gastric emptying may be useful in removing unabsorbed drug.

The opioid antagonists, naloxone and nalmefene, are specific antidotes for respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to codeine overdose, administer an opioid antagonist. An antagonist should not be administered in the absence of clinically significant respiratory depression.

Because the duration of opioid reversal is expected to be less than the duration of action of codeine in TUXARIN ER, carefully monitor the patient until spontaneous respiration is reliably reestablished. TUXARIN ER will continue to release codeine and add to the codeine load for 4 hours or longer following ingestion, necessitating prolonged monitoring. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product's prescribing information.

Hemodialysis is not routinely used to enhance the elimination of codeine or chlorpheniramine from the body. Urinary excretion of chlorpheniramine is increased when the pH of the urine is acidic; however, acid diuresis is NOT recommended to enhance elimination in overdose, as the risks of acidemia and acute tubular necrosis in patients with rhabdomyolysis far outweigh any potential benefits.