Minizide (Prazosin Hydrochloride / Polythiazide) - Drug Interactions, Contraindications, Overdosage, etc

DRUG INTERACTIONS

Drug/Laboratory Test Interactions

In a study on five patients given from 12 to 24 mg of prazosin per day for 10 to 14 days, there was an average increase of 42% in the urinary metabolite of norepinephrine and an average increase in urinary VMA of 17%. Therefore, false positive results may occur in screening tests for pheochromocytoma in patients who are being treated with prazosin. If an elevated VMA is found, prazosin should be discontinued and the patient retested after a month.

OVERDOSAGE

MINIPRESS (prazosin hydrochloride)

Accidental ingestion of at least 50 mg of MINIPRESS in a two year old child resulted in profound drowsiness and depressed reflexes. No decrease in blood pressure was noted. Recovery was uneventful.

Should overdosage lead to hypotension, support of the cardiovascular system is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by keeping the patient in the supine position. If this measure is inadequate, shock should first be treated with volume expanders. If necessary, vasopressors should then be used. Renal function should be monitored and supported as needed. Laboratory data indicate that MINIPRESS is not dialyzable because it is protein bound.

RENESE (polythiazide)

Should overdosage with RENESE occur, electrolyte balance and adequate hydration should be maintained. Gastric lavage is recommended, followed by supportive treatment. Where necessary, this may include intravenous dextrose and saline with potassium and other electrolyte therapy, administered with caution as indicated by laboratory testing at appropriate intervals.

CONTRAINDICATIONS

RENESE (polythiazide) is contraindicated in patients with anuria, and in patients known to be sensitive to thiazides or to other sulfonamide derivatives.