RESUMEN
Fifty milligrams of carvedilol and 100 mg atenolol were administered in a random order once a day for 2 months to 43 patients with mild to moderate hypertension, in a double-blind crossover study. Blood pressure, heart rate and peripheral blood flow parameters (n = 11) were recorded 2 and 24 h after the drug administration. Supine blood pressure was the same 2 h after both carvedilol and atenolol administration, but carvedilol caused a greater decrease in standing systolic blood pressure 2 h after the administration (P less than 0.05). The heart rate decreased less with carvedilol (P less than 0.01). There was no difference in the effects exerted by the two therapies on systolic blood pressure and the heart rate 24 h after drug administration, but the diastolic blood pressure was higher in patients given carvedilol (92 versus 88 mmHg; P less than 0.05). Forearm blood flow, forearm vascular resistance and calf blood flow did not change significantly with either of the therapies. In conclusion, 50 mg carvedilol once a day is an effective antihypertensive therapy, though its duration of action did not reach that of 100 mg atenolol once a day. Peripheral vasodilation was similar with both therapies.