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.