The efficacy and tolerability of
doxazosin and
atenolol in the management of mild and moderate
hypertension were compared in a multicentre, parallel study, the first year of which was randomized and double-blind. Patients who completed this first year were invited to enter a two-year extension phase; the results after the first year are presented. A total of 228 patients entered the double-blind phase (118 received
atenolol). A reduction in dose was required by 4% in each group; eight patients on
doxazosin and 11 on
atenolol were withdrawn due to adverse effects. Ninety-three of the 100
doxazosin patients and 88 of the 104
atenolol patients who completed the double-blind phase agreed to participate in the open extension study. At 24 months, the mean dose of
doxazosin was 5.2 mg/day, and of
atenolol 66.7 mg/day. From baseline levels of BP of 158/104 mmHg in the
doxazosin group and 161/103 mmHg in the
atenolol group, average reductions at 24 months were -16/-14 and -19/-15 mmHg respectively. Neither
drug had a significant effect on total
cholesterol levels. At all four points of measurement over the two years,
doxazosin decreased blood
triglyceride levels and increased
high density lipoprotein (
HDL) cholesterol and the HDL: total
cholesterol ratio.
Atenolol had the opposite effect on each of these
lipid values with the differences between the treatment groups being significant.
Doxazosin was well tolerated and was shown to be effective as monotherapy in mild and moderate
hypertension. Its effect on blood
lipids was potentially favourable, and it should therefore be regarded as an alternative first-line
drug in hypertensive patients.