Direct-acting vasodilators.

KEY POINTS AND PRACTICAL RECOMMENDATIONS: • Hydralazine and minoxidil act by dilating resistance arterioles, thus reducing peripheral resistance, with no dilating effect on the venous side of the circulation. • There is a baroreflex-mediated venoconstriction, resulting in an increase in venous return to the heart, along with a direct catecholamine-mediated positive inotropic and chronotropic stimulation of the heart. • Hydralazine therapy is usually combined with a sympathetic inhibitor to prevent expression of this reflex, as well as with a diuretic agent to prevent sodium retention caused by reduction in renal perfusion pressure. • Hydralazine is indicated in the long-term therapy of essential hypertension, in the short-term therapy of pregnancy-induced hypertension and eclampsia, and in the therapy of hypertensive crisis. • Adverse effects include the anticipated tachycardia, fluid retention, and headache, caused by the vasodilation, especially in the early days of therapy, but may frequently be prevented by the concomitant use of a ß-blocker. • As with other drugs that are N-acetylated, there is a low risk of lupus-like syndrome with high doses and long-term use. • Because of the severity of adverse effects with minoxidil, its usage is limited to persons with severe hypertension unresponsive to other treatments. • Hirsutism, a common side effect of minoxidil, is particularly bothersome in women and reverses in a few months after discontinuation. • Sodium nitroprusside is used in the intensive care setting to lower pressure in hypertensive crisis or to treat severe left ventricular failure, particularly valuable when elevated pressure or severe left ventricular failure threatens the patient's survival. • Although nitrates have not achieved widespread use as antihypertensive agents, they are effective in producing sustained blood pressure (BP) reductions when added to other antihypertensive regimens.

Sildenafil citrate for erectile dysfunction in men receiving multiple antihypertensive agents: a randomized controlled trial.

BACKGROUND: Erectile dysfunction (ED) is common among men taking antihypertensive drugs to control blood pressure. We evaluated the safety and efficacy of sildenafil citrate for treating ED in men taking multiple antihypertensive medications in a randomized, double-blind, placebo-controlled trial. METHODS: A total of 568 men (> or =18 years) with ED and hypertension who were taking two or more antihypertensives were randomized to sildenafil (n = 281) or matching placebo (n = 287) for a 6-week double-blind trial followed by a 6-week open-label phase during which all patients received sildenafil. Primary efficacy variables were questions (Q) 3 and 4 (frequency of erections and penetration) of the International Index of Erectile Function (IIEF), and secondary efficacy variables were two global efficacy assessment (GEA) questions regarding improvement in erections and intercourse. RESULTS: A total of 562 men (mean age, 59 years) took > or =1 dose of study drug. At week 6, mean scores on both Q3 and Q4 improved significantly among sildenafil-treated compared with placebo-treated patients. In regard to Q3 and Q4 there were no differences between patients taking two and those taking three or more antihypertensive agents. In all, 71% and 69% of sildenafil-treated patients reported improved erections (GEA1) and intercourse (GEA2) compared with 18% and 20% of placebo-treated patients, respectively. By week 12, >80% of all patients (regardless of initial treatment group) had improved erections and intercourse. During double-blind treatment, 40% of sildenafil-treated and 25% of placebo-treated patients experienced adverse events; fewer than 2% in each group discontinued because of adverse events. CONCLUSIONS: Sildenafil was an effective and well tolerated treatment for ED in men receiving multiple antihypertensives. The results suggest that there were no additional safety risks associated with the use of sildenafil in these patients.