Use of sildenafil (Viagra) in patients with cardiovascular disease

The pharmaceutical preparation sildenafil citrate (Viagra) is being widely prescribed as a treatment for male erectile dysfunction, a common problem t hat in the United States affects between 10 and 30 million men. The introdu ction of sildenafil has been a valuable contribution to the treatment of er ectile dysfunction, which is a relatively common occurrence in patients wit h cardiovascular disease. This article is written to appropriately caution and not to unduly alarm physicians in their use of sildenafil in patients w ith heart disease. Reported cardiovascular side effects in the normal healthy population are t ypically minor and associated with vasodilatation tie, headache, flushing, and small decreases in systolic and diastolic blood pressures). However, al though their incidence is small, serious cardiovascular events, including s ignificant hypotension, can occur in certain populations at risk. Most at r isk are individuals who are concurrently taking organic nitrates. Organic n itrate preparations are commonly prescribed to manage the symptoms of angin a pectoris. The coadministration of nitrates and Viagra significantly incre ases the risk of potentially life-threatening hypotension. Therefore, Viagr a should not be prescribed to patients receiving any form of nitrate therap y. Although definitive evidence is currently lacking, it is possible that a pr ecipitous reduction in blood pressure with nitrate use may occur over the i nitial 24 hours after a dose of Viagra. Thus, fur patients who experience a n acute cardiac ischemic event and who have taken Viagra within the past 24 hours, administration of nitrates should be avoided. In the event that nit rates are given, especially within this critical time interval, it is essen tial to have the capability to support the patient with fluid resuscitation and alpha-adrenergic agonists if needed. In patients with recurring angina after Viagra use, other nonnitrate antianginal agents, such as beta-blocke rs, should be considered. Other patients in whom the use of Viagra is potentially hazardous include t hose with active coronary ischemia; those with congestive heart failure and borderline low blood volume and low blood pressure status: those with comp licated, multidrug, antihypertensive therapy regimens; and those taking med ications that may affect the metabolic clearance of Viagra. With respect to patients following complicated multidrug, antihypertensive programs, the r andomized studies included a large number of hypertensive patients. However , most patients were controlled with 1 antihypertensive agent, and only a s mall number were controlled with 3 antihypertensive agents. Until adequate studies are done in these subgroups of patients, sildenafil should be presc ribed with caution. Viagra acts as a selective inhibitor of cyclic GMP (cGMP)-specific phosphod iesterase type 5, resulting in smooth muscle relaxation, vasodilatation, an d enhanced penile erection. Although the cardiovascular effects of sildenaf il reported in available randomized, controlled clinical trials were relati vely minor, heart disease patients represented only a small fraction of stu died patients, and patients with heart failure, patients with myocardial in farction or stroke within 6 months, or patients with uncontrolled hypertens ion were not included in these studies. Thus, there are possible problems i n the use of Viagra in these patients that have not been adequately studied . Given the increasing reports of deaths in which the use of Viagra may be im plicated, clinicians need to exercise caution when advising their patients with heart disease about taking this medication. Specific recommendations r egarding sildenafil (Viagra) and the cardiac patient are summarized in the following Table.