Avalide Drug Information

General Considerations

The side effects of irbesartan are generally rare and apparently independent of dose; those of hydrochlorothiazide are a mixture of dose-dependent (primarily hypokalemia) and dose-independent phenomena (e.g., pancreatitis), the former much more common than the latter. Maximum antihypertensive effects are attained within 2 to 4 weeks after a change in dose. AVALIDE may be administered with or without food.

AVALIDE may be administered with other antihypertensive agents. Renal Impairment The usual regimens of therapy with AVALIDE may be followed as long as the patient's creatinine clearance is >30 mL/min. In patients with more severe renal impairment, loop diuretics are preferred to thiazides, so AVALIDE is not recommended.

Hepatic Impairment No dosage adjustment is necessary in patients with hepatic impairment.

Add-On Therapy

In patients not controlled on monotherapy with irbesartan or hydrochlorothiazide, the recommended doses of AVALIDE, in order of increasing mean effect, are (irbesartan and hydrochlorothiazide) 150/12.5 mg, 300/12.5 mg, and 300/25 mg. The largest incremental effect will likely be in the transition from monotherapy to 150/12.5 mg.

Replacement Therapy

AVALIDE may be substituted for the titrated components.

Initial Therapy

The usual starting dose is AVALIDE 150/12.5 mg once daily. The dosage can be increased after 1 to 2 weeks of therapy to a maximum of 300/25 mg once daily as needed to control blood pressure . AVALIDE is not recommended as initial therapy in patients with intravascular volume depletion .

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates. Irbesartan and Hydrochlorothiazide AVALIDE tablets have been evaluated for safety in 1694 patients treated for essential hypertension in 6 clinical trials.

In Studies I through IV with AVALIDE, no adverse events peculiar to this combination drug product have been observed. Adverse events have been limited to those that were reported previously with irbesartan or hydrochlorothiazide (HCTZ). The overall incidence of adverse events was similar with the combination and placebo. In general, treatment with AVALIDE was well tolerated.

For the most part, adverse events have been mild and transient in nature and have not required discontinuation of therapy. In controlled clinical trials, discontinuation of AVALIDE therapy due to clinical adverse events was required in only 3.6%. This incidence was significantly less (p=0.023) than the 6.8% of patients treated with placebo who discontinued therapy. In these double-blind controlled clinical trials, the following adverse events reported with AVALIDE occurred in ≥1% of patients, and more often on the irbesartan and hydrochlorothiazide combination than on placebo, regardless of drug relationship: Irbesartan/HCTZ (n=898) (%) Placebo (n=236) (%) Irbesartan (n=400) (%) HCTZ (n=380) (%) Body as a Whole Chest Pain 2 1 2 2 Fatigue 6 3 4 3 Influenza 3 1 2 2 Cardiovascular Edema 3 3 2 2 Tachycardia 1 0 1 1 Gastrointestinal Abdominal Pain 2 1 2 2 Dyspepsia/heartburn 2 1 0 2 Nausea/vomiting 3 0 2 2 Immunology Allergy 1 0 1 1 Musculoskeletal Musculoskeletal Pain 6 5 6 10 Nervous System Dizziness 8 4 6 5 Dizziness Orthostatic 1 0 1 1 Renal/Genitourinary Abnormality Urination 2 1 1 2 The following adverse events were also reported at a rate of 1% or greater, but were as, or more, common in the placebo group: headache, sinus abnormality, cough, URI, pharyngitis, diarrhea, rhinitis, urinary tract infection, rash, anxiety/nervousness, and muscle cramp.

Adverse events occurred at about the same rates in men and women, older and younger patients, and black and non-black patients. Adverse events in Studies V and VI were similar to those described above in Studies I through IV. Irbesartan Other adverse events that have been reported with irbesartan, without regard to causality, are listed below: Body as a Whole: fever, chills, orthostatic effects, facial edema, upper extremity edema Cardiovascular: flushing, hypertension, cardiac murmur, myocardial infarction, angina pectoris, hypotension, syncope, arrhythmic/conduction disorder, cardiorespiratory arrest, heart failure, hypertensive crisis Dermatologic: pruritus, dermatitis, ecchymosis, erythema face, urticaria Endocrine/Metabolic/Electrolyte Imbalances: sexual dysfunction, libido change, gout Gastrointestinal: diarrhea, constipation, gastroenteritis, flatulence, abdominal distention Musculoskeletal/Connective Tissue: musculoskeletal trauma, extremity swelling, muscle cramp, arthritis, muscle ache, musculoskeletal chest pain, joint stiffness, bursitis, muscle weakness Nervous System: anxiety/nervousness, sleep disturbance, numbness, somnolence, vertigo, emotional disturbance, depression, paresthesia, tremor, transient ischemic attack, cerebrovascular accident Renal/Genitourinary: prostate disorder Respiratory: cough, upper respiratory infection, epistaxis, tracheobronchitis, congestion, pulmonary congestion, dyspnea, wheezing Special Senses: vision disturbance, hearing abnormality, ear infection, ear pain, conjunctivitis Hydrochlorothiazide Other adverse events that have been reported with hydrochlorothiazide, without regard to causality, are listed below: Body as a Whole: weakness Digestive: pancreatitis, jaundice (intrahepatic cholestatic jaundice), sialadenitis, cramping, gastric irritation Hematologic: aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia Hypersensitivity: purpura, photosensitivity, urticaria, necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory distress including pneumonitis and pulmonary edema, anaphylactic reactions Metabolic: hyperglycemia, glycosuria, hyperuricemia Musculoskeletal: muscle spasm Nervous System/Psychiatric: restlessness Renal: renal failure, renal dysfunction, interstitial nephritis Skin: erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis Special Senses: transient blurred vision, xanthopsia Initial Therapy In the moderate hypertension Study V (mean SeDBP between 90 and 110 mmHg), the types and incidences of adverse events reported for patients treated with AVALIDE were similar to the adverse event profile in patients on initial irbesartan or HCTZ monotherapy. There were no reported events of syncope in the AVALIDE treatment group and there was one reported event in the HCTZ treatment group.

The incidences of prespecified adverse events on AVALIDE, irbesartan, and HCTZ, respectively, were: 0.9%, 0%, and 0% for hypotension; 3.0%, 3.8%, and 1.0% for dizziness; 5.5%, 3.8%, and 4.8% for headache; 1.2%, 0%, and 1.0% for hyperkalemia; and 0.9%, 0%, and 0% for hypokalemia. The rates of discontinuation due to adverse events on AVALIDE, irbesartan alone, and HCTZ alone were 6.7%, 3.8%, and 4.8%. In the severe hypertension (SeDBP ≥110 mmHg) Study VI, the overall pattern of adverse events reported through 7 weeks of follow-up was similar in patients treated with AVALIDE as initial therapy and in patients treated with irbesartan as initial therapy. The incidences of the prespecified adverse events on AVALIDE and irbesartan, respectively, were: 0% and 0% for syncope; 0.6% and 0% for hypotension; 3.6% and 4.0% for dizziness; 4.3% and 6.6% for headache; 0.2% and 0% for hyperkalemia; and 0.6% and 0.4% for hypokalemia.

The rates of discontinuation due to adverse events were 2.1% and 2.2%.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of AVALIDE. 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. Decisions to include these reactions in labeling are typically based on one or more of the following factors: seriousness of the reaction, frequency of reporting, or strength of causal connection to AVALIDE. Irbesartan and hydrochlorothiazide Blood and lymphatic system: Thrombocytopenia Hepatobiliary: Hepatitis, Jaundice Renal and urinary: Impaired renal function including renal failure Skin and subcutaneous tissue: Urticaria Irbesartan Blood and lymphatic system: Anemia Ear and labyrinth: Tinnitus Gastrointestinal: Intestinal angioedema Skin and subcutaneous tissue: Angioedema (involving swelling of the face, lips, pharynx, and/or tongue) Immune system: Anaphylactic reaction including anaphylactic shock Investigations: Increased CPK (Creatine Phosphokinase) Metabolism and nutrition: Hyperkalemia, Hypoglycemia in diabetic patients Hydrochlorothiazide Eye: Acute angle-closure glaucoma, Acute myopia, and Choroidal effusion Non-melanoma Skin Cancer Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses.

The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥50,000 mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year.

Laboratory Abnormalities

In controlled clinical trials, clinically important changes in standard laboratory parameters were rarely associated with administration of AVALIDE. Creatinine, Blood Urea Nitrogen: Minor increases in blood urea nitrogen (BUN) or serum creatinine were observed in 2.3% and 1.1%, respectively, of patients with essential hypertension treated with AVALIDE alone. No patient discontinued taking AVALIDE due to increased BUN. One patient discontinued taking AVALIDE due to a minor increase in serum creatinine. Liver Function Tests: Occasional elevations of liver enzymes and/or serum bilirubin have occurred.

In patients with essential hypertension treated with AVALIDE alone, one patient was discontinued due to elevated liver enzymes. Serum Electrolytes:

Nonsteroidal Anti-inflammatory Agents Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) Irbesartan

In patients who are elderly, volume depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists, including irbesartan, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Therefore, monitor renal function and blood pressure periodically in patients receiving irbesartan and NSAID therapy.

Hydrochlorothiazide Administration of a nonsteroidal anti-inflammatory agent, including a selective COX-2 inhibitor can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing, and thiazide diuretics. Therefore, when AVALIDE (irbesartan and hydrochlorothiazide) tablets and nonsteroidal anti-inflammatory agents are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained.

Dual Blockade of the Renin-Angiotensin System (RAS) Dual blockade of the

RAS with angiotensin-receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Closely monitor blood pressure, renal function, and electrolytes in patients on AVALIDE and other agents that affect the RAS. In most patients no benefit has been associated with using two RAS inhibitors concomitantly. In general, avoid combined use of RAS inhibitors.

Do not coadminister aliskiren with AVALIDE in patients with diabetes. Avoid use of aliskiren with AVALIDE in patients with renal impairment (GFR <60 mL/min).

Agents Increasing Serum Potassium Coadministration of

AVALIDE with other drugs that raise serum potassium levels may result in hyperkalemia, sometimes severe. Monitor serum potassium in such patients.

Antidiabetic Drugs (oral agents and insulin) Dosage adjustment of the antidiabetic drug

may be required when coadministered with hydrochlorothiazide.

Cholestyramine and Colestipol Resins Absorption of hydrochlorothiazide is impaired in the presence

of anionic exchange resins. Stagger the dosage of hydrochlorothiazide and the resin such that AVALIDE is administered at least 4 hours before or 4 to 6 hours after the administration of the resin.

Lithium Increases in serum lithium concentrations and lithium toxicity have been reported

with concomitant use of irbesartan or thiazide diuretics. Monitor lithium levels in patients receiving AVALIDE and lithium.

Carbamazepine

Concomitant use of carbamazepine and hydrochlorothiazide has been associated with the risk of symptomatic hyponatremia. Monitor electrolytes during concomitant use.

Pregnancy Risk Summary AVALIDE can cause fetal harm when administered to a pregnant woman. Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death . Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. When pregnancy is detected, discontinue AVALIDE as soon as possible.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes regardless of drug exposure. 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 embryo-fetal risk Hypertension in pregnancy increases the maternal risk for preeclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section and postpartum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death.

Pregnant women with hypertension should be carefully monitored and managed accordingly. Fetal/neonatal adverse reactions Oligohydramnios in pregnant women who use drugs affecting the renin-angiotensin system in the second and third trimesters of pregnancy can result in the following: reduced fetal renal function leading to anuria and renal failure, fetal lung hypoplasia, skeletal deformations, including skull hypoplasia, hypotension, and death. Perform serial ultrasound examinations to assess the intra-amniotic environment.

Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury. Closely observe infants with histories of in utero exposure to AVALIDE for hypotension, oliguria, and hyperkalemia and other symptoms of renal impairment.

In neonates with a history of in utero exposure to AVALIDE, if oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion. Exchange transfusion or dialysis may be required as means of reversing hypotension and/or substituting for disordered renal function. Thiazides cross the placenta, and use of thiazides during pregnancy is associated with a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults . Data Animal data Irbesartan crosses the placenta in rats and rabbits.

In female rats given irbesartan prior to mating through gestation and lactation at oral doses of 50, 180, or 650 mg/kg/day (1.6 to 21.1 times the maximum recommended human dose (MRHD) based on body surface area), fetuses examined on Gestation Day 20 showed increased incidences of hydroureter and renal pelvic cavitation and/or absence of renal papilla in all irbesartan-treated groups. Subcutaneous edema also occurred in fetuses at maternal doses ≥180 mg/kg/day (5.8 times the MRHD). These anomalies occurred when female rats received irbesartan from prior to mating through Day 20 of gestation but were not observed in pups postnatally in the same study, or when irbesartan was given to pregnant rats only during organogenesis (Gestation Day 6 through Gestation Day 15) at oral doses from 50 to 450 mg/kg/day (up to 14.6 times the MRHD). In addition, no adverse effects on kidney development were observed in pups from dams given irbesartan from Gestation Day 15 through Lactation Day 24 at doses of 50, 180, or 650 mg/kg/day (up to 21.1 times the MRHD). The observed effects are believed to be late gestational effects of the drug. Pregnant rabbits given oral doses of irbesartan of 30 mg/kg/day (1.9 times the MRHD based on body surface area) experienced a high rate of maternal mortality and abortion.

Surviving females had a slight increase in early resorptions and a corresponding decrease in live fetuses. Radioactivity was present in the rat and rabbit fetuses during late gestation following oral doses of radiolabeled irbesartan. When pregnant mice and rats were given hydrochlorothiazide at doses up to 3000 and 1000 mg/kg/day, respectively (about 600 and 400 times the MRHD) during their respective periods of major organogenesis, there was no evidence of fetal harm.

A development toxicity study was performed in rats with doses of 50/50 mg/kg/day and 150/150 mg/kg/day irbesartan and hydrochlorothiazide. Although the high dose combination appeared to be more toxic to the dams than either drug alone, there did not appear to be an increase in toxicity to the developing embryos.

Pediatric Use Safety and effectiveness in pediatric patients have not been established.

is contraindicated in patients who are hypersensitive to any component of this product. Because of the hydrochlorothiazide component, this product is contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs. Do not coadminister aliskiren with AVALIDE in patients with diabetes . Hypersensitivity to any component of this product.

Anuria. Hypersensitivity to sulfonamide-derived drugs. Do not coadminister aliskiren with AVALIDE in patients with diabetes.

Irbesartan No data are available in regard to overdosage in humans. However, daily doses of 900 mg for 8 weeks were well tolerated. The most likely manifestations of overdosage are expected to be hypotension and tachycardia; bradycardia might also occur from overdose.

Irbesartan is not removed by hemodialysis. To obtain up-to-date information about the treatment of overdosage, a good resource is a certified regional Poison Control Center. Telephone numbers of certified Poison Control Centers are listed in the Physicians' Desk Reference (PDR). In managing overdose, consider the possibilities of multiple-drug interactions, drug-drug interactions, and unusual drug kinetics in the patient.

Laboratory determinations of serum levels of irbesartan are not widely available, and such determinations have, in any event, no established role in the management of irbesartan overdose. Acute oral toxicity studies with irbesartan in mice and rats indicated acute lethal doses were in excess of 2000 mg/kg, about 25-fold and 50-fold the MRHD (300 mg) based on body surface area. Hydrochlorothiazide The most common signs and symptoms of overdose observed in humans are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis.

If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias. The degree to which hydrochlorothiazide is removed by hemodialysis has not been established. The oral LD 50 of hydrochlorothiazide is greater than 10 g/kg in both mice and rats.