[Anti-hypertensive efficacy and tolerability of sustained-release prazosin hydrochloride. A Brazilian multicenter study].
OBJECTIVE
To evaluate the efficacy and tolerability of a single daily dose of sustained-release (SR) formulation of prazosin hydrochloride.


METHODS
1393 outpatients in a multicenter open comparative trial. 644 patients had mild hypertension and 749 patients had moderate hypertension. The mean age was 47.63 years, 745 (53.52%) were male, 1011 (72.84%) white and 279 (20.1%) black. The patients received prazosin hydrochloride SR during 4 weeks in an initial dose of 1 mg, adjusted to a maximum of 6 mg in order to decrease the diastolic blood pressure (DBP) to 90 mmHg or less.


RESULTS
The mean daily dose was 2.08 mg. At the end of the study, 1274 (91.46%) patients had DBP less than or equal to 90 mmHg or less. 624 patients were in the mild hypertension group and 650 patients were in the moderate hypertension group. The number of patients under DBP control in the first three weeks was 426 (first week), 844 (second week) and 1147 (third week). The DBP decreased from the mean value of 104 +/- 5 mmHg to 88 +/- 8 mmHg (p less than 0.05). The mean heart rate ranged from 82 +/- 9 beats/min (pre-treatment) to 80 +/- 8 beats/min (fourth week). Adverse effects were identified in 377 (27.06%) patients, total of 444 episodes, the more frequent being dizziness. Only 8 (2.12%) patients had to reduce the doses of prazosin hydrochloride SR and 5 (1.32%) had to discontinue the treatment on account of the adverse effects of the drug.


CONCLUSIONS
Prazosin hydrochloride SR in a single daily dose seems to be an advance in the treatment of patients with mild and moderate hypertension.
Spritzer
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N
Instituto de Cardiologia do RS, Porto Alegre, RS.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003692:Delayed-Action Preparations; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011224:Prazosin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D003692:Delayed-Action Preparations; D011224:Prazosin
Eficácia anti-hipertensiva e tolerabilidade do cloridrato de prazosina de liberação lenta. Estudo multicêntrico brasileiro.