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warnings
WARNINGS Methyclothiazide shares with other thiazides the propensity to deplete potassium reserves to an unpredictable degree. There have been isolated reports that certain non-edematous individuals developed severe fluid and electrolyte derangements after only brief exposure to normal doses of thiazide and non-thiazide diuretics. Thiazides should be used with caution in patients with renal disease or significant impairment of renal function, since azotemia may be precipitated and cumulative drug effects may occur. Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma. Sensitivity reactions may occur in patients with a history of allergy or bronchial asthma. The possibility of exacerbation or activation of systemic lupus erythematosus has been reported. Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy.
ADVERSE REACTIONS Adverse reactions are usually reversible upon reduction of dosage or discontinuation of methyclothiazide tablets. Whenever adverse reactions are moderate or severe, it may be necessary to discontinue the drug. The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency. Consequently the reactions are categorized by organ system and are listed in decreasing order of severity and not frequency. Body as a Whole: Headache, cramping, weakness. Cardiovascular System: Orthostatic hypotension (may be potentiated by alcohol, barbiturates, or narcotics). Digestive System: Pancreatitis, jaundice (intrahepatic cholestatic), sialadenitis, vomiting, diarrhea, nausea, gastric irritation, constipation, anorexia. Hemic and Lymphatic System: Aplastic anemia, hemolytic anemia, agranulocytosis, leukopenia, thrombocytopenia. Hypersensitivity Reactions: Anaphylactic reactions, necrotizing angiitis (vasculitis, cutaneous vasculitis), Stevens-Johnson Syndrome, respiratory distress including pneumonitis and pulmonary edema, fever, purpura, urticaria, rash, photosensitivity. Metabolic and Nutritional Disorders: Hyperglycemia, hyperuricemia, electrolyte imbalance (see PRECAUTIONS section), hypercalcemia. Nervous System: Vertigo, dizziness, paresthesias, muscle spasm, restlessness. Special Senses: Transient blurred vision, xanthopsia. Urogenital System: Glycosuria.