Hyperkalemia Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/liter) can occur with all potassium-sparing diuretic combinations, including triamterene and hydrochlorothiazide capsules. Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment) and in the elderly or severely ill. Since uncorrected hyperkalemia may be fatal, serum potassium levels must be monitored at frequent intervals especially in patients first receiving triamterene and hydrochlorothiazide capsules, when dosages are changed, or with any illness that may influence renal function.
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.