title: Influence of dosage and dietary sodium on the first-dose effects of prazosin.
abstract: The effects of the first dose of prazosin were assessed in hypertensive patients on different sodium intakes. Patients received 250, 100, or 30 mmol sodium per 24 hours for a week before taking 2 mg or 0-5 mg prazosin. The acute effects of prazosin on blood pressure and pulse rate were milder with a high sodium intake. On the 100-mmol intake symptomatic postural hypotension occurred in five out of seven patients given 2 mg prazosin and in two out of four given a 0-5-mg dose, whereas those taking 2 mg or 0-5 mg and a 250-mmol sodium intake experienced no postural symptoms. These findings indicate that particular care should be taken in starting prazosin treatment in sodium-depleted patients.
mesh_terms: D000328:Adult; D004032:Diet; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007024:Hypotension, Orthostatic / Q000378:metabolism / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011224:Prazosin / Q000008:administration & dosage* / Q000009:adverse effects; D011799:Quinazolines / Q000008:administration & dosage*; D012964:Sodium / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D011799:Quinazolines; D012964:Sodium; D011224:Prazosin