Triamterene and Hydrochlorothiazide

INDICATIONS AND USAGE This fixed combination drug is not indicated for the initial therapy of edema or hypertension except in individuals in whom the development of hypokalemia cannot be risked. Triamterene and hydrochlorothiazide capsules, USP are indicated for the treatment of hypertension or edema in patients who develop hypokalemia on hydrochlorothiazide alone. Triamterene and hydrochlorothiazide capsules, USP are also indicated for those patients who require a thiazide diuretic and in whom the development of hypokalemia cannot be risked. Triamterene and hydrochlorothiazide capsules, USP may be used alone or as an adjunct to other antihypertensive drugs, such as beta-blockers. Since triamterene and hydrochlorothiazide capsules, USP may enhance the action of these agents, dosage adjustments may be necessary. Usage in Pregnancy: The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developed toxemia. Edema during pregnancy may arise from pathological causes or from the physiologic and mechanical consequences of pregnancy. Diuretics are indicated in pregnancy when edema is due to pathologic causes, just as they are in the absence of pregnancy. Dependent edema in pregnancy resulting from restriction of venous return by the expanded uterus is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy which is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances this edema may cause extreme discomfort which is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

DOSAGE AND ADMINISTRATION The usual dose of triamterene and hydrochlorothiazide capsules, USP is one or two capsules given once daily, with appropriate monitoring of serum potassium and of the clinical effect (see WARNINGS, Hyperkalemia ).

CONTRAINDICATIONS Antikaliuretic Therapy and Potassium Supplementation: Triamterene and hydrochlorothiazide capsules, USP should not be given to patients receiving other potassium-sparing agents such as spironolactone, amiloride, or other formulations containing triamterene. Concomitant potassium-containing salt substitutes should also not be used. Potassium supplementation should not be used with triamterene and hydrochlorothiazide capsules, USP except in severe cases of hypokalemia. Such concomitant therapy can be associated with rapid increases in serum potassium levels. If potassium supplementation is used, careful monitoring of the serum potassium level is necessary. Impaired Renal Function: Triamterene and hydrochlorothiazide capsules, USP are contraindicated in patients with anuria, acute and chronic renal insufficiency, or significant renal impairment. Hypersensitivity: Hypersensitivity to either drug in the preparation or to other sulfonamide-derived drugs is a contraindication. Hyperkalemia: Triamterene and hydrochlorothiazide capsules, USP should not be used in patients with pre-existing elevated serum potassium.

ADVERSE REACTIONS Adverse effects are listed in decreasing order of severity. Hypersensitivity: Anaphylaxis, rash, urticaria, subacute cutaneous lupus erythematosus-like reactions, photosensitivity. Cardiovascular: Arrhythmia, postural hypotension. Metabolic: Diabetes mellitus, hyperkalemia, hypokalemia, hyponatremia, acidosis, hypercalcemia, hyperglycemia, glycosuria, hyperuricemia, hypochloremia. Gastrointestinal: Jaundice and/or liver enzyme abnormalities, pancreatitis, nausea and vomiting, diarrhea, constipation, abdominal pain. Renal: Acute renal failure (one case of irreversible renal failure has been reported), interstitial nephritis, renal stones composed primarily of triamterene, elevated BUN and serum creatinine, abnormal urinary sediment. Hematologic: Leukopenia, thrombocytopenia and purpura, megaloblastic anemia. Musculoskeletal: Muscle cramps. Central Nervous System: Weakness, fatigue, dizziness, headache, dry mouth. Miscellaneous: Impotence, sialadenitis. Thiazides alone have been shown to cause the following additional adverse reactions: Central Nervous System: Paresthesias, vertigo. Ophthalmic: Xanthopsia, transient blurred vision. Respiratory: Allergic pneumonitis, pulmonary edema, respiratory distress. Other: Necrotizing vasculitis, exacerbation of lupus. Hematologic: Aplastic anemia, agranulocytosis, hemolytic anemia. Neonate and infancy: Thrombocytopenia and pancreatitis–rarely, in newborns whose mothers have received thiazides during pregnancy. Skin: Erythema multiforme, including Stevens-Johnson syndrome; exfoliative dermatitis, including toxic epidermal necrolysis. Postmarketing Experience 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. To report SUSPECTED ADVERSE REACTIONS, contact Viona Pharmaceuticals Inc. at 1-888-304-5011 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Drug Interactions Angiotensin-Converting Enzyme Inhibitors Potassium-sparing agents should be used with caution in conjunction with angiotensin-converting enzyme (ACE) inhibitors due to an increased risk of hyperkalemia. Oral Hypoglycemic Drugs Concurrent use with chlorpropamide may increase the risk of severe hyponatremia. Nonsteroidal Anti-Inflammatory Drugs A possible interaction resulting in acute renal failure has been reported in a few patients on triamterene and hydrochlorothiazide when treated with indomethacin, a nonsteroidal anti-inflammatory agent. Caution is advised in administering nonsteroidal anti-inflammatory agents with triamterene and hydrochlorothiazide. Lithium Lithium generally should not be given with diuretics because they reduce its renal clearance and increase the risk of lithium toxicity. Read prescribing information for lithium preparations before use of such concomitant therapy with triamterene and hydrochlorothiazide. Surgical Considerations Thiazides have been shown to decrease arterial responsiveness to norepinephrine (an effect attributed to loss of sodium). This diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use. Thiazides have also been shown to increase the paralyzing effect of nondepolarizing muscle relaxants such as tubocurarine (an effect attributed to potassium loss); consequently, caution should be observed in patients undergoing surgery. Other Considerations Concurrent use of hydrochlorothiazide with amphotericin B or corticosteroids or corticotropin (ACTH) may intensify electrolyte imbalance, particularly hypokalemia, although the presence of triamterene minimizes the hypokalemic effect. Thiazides may add to or potentiate the action of other antihypertensive drugs. See INDICATIONS AND USAGE for concomitant use with other antihypertensive drugs. The effect of oral anticoagulants may be decreased when used concurrently with hydrochlorothiazide; dosage adjustments may be necessary. Triamterene and hydrochlorothiazide may raise the level of blood uric acid; dosage adjustments of antigout medication may be necessary to control hyperuricemia and gout. The following agents given together with triamterene may promote serum potassium accumulation and possibly result in hyperkalemia because of the potassium-sparing nature of triamterene, especially in patients with renal insufficiency: blood from blood bank (may contain potassium up to 30 mEq/L of plasma or up to 65 mEq/L of whole blood when stored for more than 10 days); low-salt milk (may contain potassium up to 60 mEq/L); potassium-containing medications (such as parenteral penicillin G potassium); salt substitutes (most contain substantial amounts of potassium). Exchange resins, such as sodium polystyrene sulfonate, whether administered orally or rectally, reduce serum potassium levels by sodium replacement of the potassium; fluid retention may occur in some patients because of the increased sodium intake. Chronic or overuse of laxatives may reduce serum potassium levels by promoting excessive potassium loss from the intestinal tract; laxatives may interfere with the potassium-retaining effects of triamterene. The effectiveness of methenamine may be decreased when used concurrently with hydrochlorothiazide because of alkalinization of the urine. Information for Patients Non-Melanoma Skin Cancer Instruct patients taking hydrochlorothiazide to protect skin from the sun and undergo regular skin cancer screening.

DESCRIPTION Triamterene is an antikaliuretic agent and hydrochlorothiazide is a diuretic/antihypertensive agent. At 50°C, triamterene is practically insoluble in water (less than 0.1%). It is soluble in formic acid, sparingly soluble in methoxyethanol, and very slightly soluble in alcohol. Triamterene is 2,4,7-triamino-6-phenylpteridine with a chemical formula of C 12 H 11 N 7 and a molecular weight of 253.27. The structural formula for triamterene is: TRIAMTERENE TRIAMTERENE Hydrochlorothiazide is slightly soluble in water. It is soluble in dilute ammonia, dilute aqueous sodium hydroxide, and dimethylformamide. It is sparingly soluble in methanol. Hydrochlorothiazide is 6-chloro-3,4-dihydro-2 H -1,2, 4-benzothiadiazine-7-sulfonamide 1,1-dioxide with a chemical formula of C 7 H 8 ClN 3 O 4 S 2 and a molecular weight of 297.75. The structural formula for hydrochlorothiazide is: HYDROCHLOROTHIAZIDE HYDROCHLOROTHIAZIDE Each capsule, for oral administration, contains 37.5 mg triamterene and 25 mg hydrochlorothiazide or 50 mg triamterene and 25 mg hydrochlorothiazide. The 37.5 mg triamterene and 25 mg hydrochlorothiazide capsule inactive ingredients include: citric acid, corn starch, glycine, anhydrous lactose, magnesium stearate, Polysorbate 80, povidone, and sodium starch glycolate. The capsule shells and imprinting inks contain: D & C Yellow #10 Aluminum Lake, FD & C Blue #1 Aluminum Lake, FD & C Blue #2 Aluminum Lake, FD & C Red #40 Aluminum Lake, gelatin, pharmaceutical glaze, propylene glycol, synthetic black iron oxide, and titanium dioxide. The 37.5 mg triamterene and 25 mg hydrochlorothiazide capsule meets USP Dissolution Test 3 . The 50 mg triamterene and 25 mg hydrochlorothiazide capsule inactive ingredients include: lactose monohydrate, magnesium stearate, povidone, corn starch. The capsule shells and imprinting inks contain: D&C Red # 40, gelatin, titanium dioxide, pharmaceutical glaze, propylene glycol and simethicone. The 50 mg triamterene and 25 mg hydrochlorothiazide capsule meets USP Dissolution Test 2 . Triamterene Chemical Fromula Hydrochlorothiazide Chemical Structure

OVERDOSAGE Electrolyte imbalance is the major concern ( see WARNINGS section ). Symptoms reported include: polyuria, nausea, vomiting, weakness, lassitude, fever, flushed face, and hyperactive deep tendon reflexes. If hypotension occurs, it may be treated with pressor agents such as levarterenol to maintain blood pressure. Carefully evaluate the electrolyte pattern and fluid balance. Induce immediate evacuation of the stomach through emesis or gastric lavage. There is no specific antidote. Reversible acute renal failure following ingestion of 50 tablets of a product containing a combination of 50 mg triamterene and 25 mg hydrochlorothiazide has been reported. Although triamterene is largely protein-bound (approximately 67%), there may be some benefit to dialysis in cases of overdosage.

HOW SUPPLIED Triamterene and Hydrochlorothiazide Capsules USP, 37.5 mg/25 mg are light yellow to yellow colored powder filled in size '4' empty hard gelatin capsule having yellow opaque colored cap imprinted with "855" in black ink and white opaque colored body and are supplied as follows: NDC 68382-855-01 in bottles of 100 capsules NDC 68382-855-05 in bottles of 500 capsules NDC 68382-855-10 in bottles of 1000 capsules NDC 68382-855-77 in unit-dose blister cartons of 100 (10 X 10) Unit-dose Capsules Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Protect from light. Dispense in a tight, light-resistant container as defined in the USP. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. Manufactured by: Cadila Healthcare Ltd. Matoda, Ahmedabad, India Distributed by: Zydus Pharmaceuticals USA Inc. Pennington, NJ 08534 Rev.: 09/15 Revision Date: 07/09/2015