Faculty Bibliography

The effects of prazosin and atenolol monotherapy on plasma lipid concentrations were compared in 51 patients with mild to moderate essential hypertension. Prazosin monotherapy (mean dose 5.4 +/- 5.3 mg per day) resulted in a significant decrease in total and low-density lipoprotein cholesterol concentrations; these changes were evident at three months and at six to 12 months. Atenolol monotherapy (mean dose 66 +/- 23 mg per day) resulted in a significant increase in plasma triglyceride concentration that persisted during one year of treatment. The deletion of thiazide from the regimen of prazosin plus thiazide resulted in a small stepwise decrease in plasma triglyceride concentration over 12 months of observation. The addition of polythiazide (0.5 mg two to three times weekly) to the regimen of patients in whom acceptable blood pressure was not attained with prazosin or atenolol monotherapy resulted in a decrease in blood pressure, averaging 18.8 mm Hg for systolic and 10.3 mm Hg for diastolic, and a small, though significant, increase in the concentration of low-density lipoprotein cholesterol. It is suggested that the effects of prazosin on plasma lipid composition may be mediated, at least in part, by blocking an action of either the sympathetic nervous system or circulating catecholamines that normally modulate lipoprotein metabolism and might mediate the lipid alterations induced by thiazide diuretics.

The effects of prazosin and propranolol on total serum cholesterol concentration, low-density lipoprotein and high-density lipoprotein cholesterol fractions, and serum triglyceride concentration were compared in a crossover study in 29 patients with mild to moderate essential hypertension. All patients received polythiazide at a constant dose throughout control and drug treatment periods. Comparable blood pressure reduction was achieved with prazosin (9.3 +/- 7.1 mg per day) and propranolol (183.6 +/- 154.5 mg per day). Prazosin administration was associated with a significant reduction in the concentrations of total serum cholesterol (-5.5 percent), triglyceride (-20.0 percent), and low-density lipoprotein cholesterol (-10.1 percent). High-density lipoprotein cholesterol concentration increased (+8.0 percent) as did the ratio high-density lipoprotein: total cholesterol (+14.1 percent). No significant changes in any of the serum lipid fractions were observed during propranolol administration.