Summary Statement of the American College of Cardiology and the American Heart Association on the Use of Sildenafil (Viagra) in Patients at Clinical Risk From Cardiovascular Effects; August 10, 1998;

The American College of Cardiology (ACC), in conjunction with the American Heart Association (AHA), is currently developing an expert consensus document titled "The Use of Sildenafil (Viagra) in Patients at Clinical Risk From Cardiovascular Effects." Pending ACC Board of Trustees and AHA approval, the document is expected to be released in December 1998. Until the document is available, the ACC and the AHA are making interim recommendations to assist physicians managing cardiac patients on Viagra. This statement reflects the current state of knowledge, realizing that modifications may be necessary in the near future as more information is evaluated.

Recommendation for Prescribing Viagra in Patients at Clinical Risk From Cardiovascular Effects

Viagra is absolutely contraindicated in patients who are taking any chronic nitrate drug therapy or who utilize short-acting nitrate-containing medications, due to the risk of developing potentially life-threatening hypotension. Therefore, nitrates and Viagra should not be taken concurrently. In addition, the combination of Viagra and inhaled nitrates, such as amyl nitrates or "poppers" (an illicit recreational drug) could prove to be fatal and should be avoided.

The cardiovascular effects of Viagra may be potentially hazardous for patients with certain medical profiles, and clinicians need to exercise caution when advising the following patients who are considering taking Viagra.

• Patients with active coronary ischemia who are not on nitrates,
• Patients with congestive heart failure and borderline low blood pressure and borderline low volume status,
• Patients on a complicated multi-drug, anti-hypertensive program, and
• Patients on drugs (e.g., erythromycin, cimetidine) or who have conditions (e.g., liver or renal disease) that can prolong the half-life of Viagra.

Management of Acute Cardiac Ischemic Syndromes With Patients on Viagra

• In the event that a patient on Viagra experiences an acute cardiac ischemic event, the physician should first try to establish the time of the last dose of Viagra. Definitive evidence is currently lacking, but it is possible that a precipitous reduction in blood pressure may occur over the initial 24 hours following a dose of Viagra. Administration of nitrates in this time interval should be avoided. In the event that nitrates are given following Viagra administration, it is essential to have the capability to support the patient with fluid resuscitation and alpha-adrenergic agonists, if needed. In patients in whom the half-life of Viagra may be prolonged, such as in renal and hepatic dysfunction, a more extended period of time between the Viagra administration and the nitrate administration may be required. In patients with recurring mild angina after Viagra use, other non-nitrate, anti-anginal agents, such as beta blockers, should be considered.
• Patients on Viagra with an acute myocardial infarction should be treated in the usual manner as described in the ACC/AHA clinical practice guidelines, including, where appropriate, primary angioplasty or thrombolytics. The only difference is that nitrates are contraindicated for these patients.
• In patients with unstable angina, therapy should include only non-nitrate, anti-anginal medications but otherwise adhere to principles established in the clinical practice guideline available from the Agency for Health Care Policy and Research. To date, there is no evidence of significant interactions with heparin, beta-adrenergic blockers, calcium channel blockers, narcotics, and aspirin. These agents can be used as appropriate.

Treatment of the Hypotensive Patient With Inadvertent Viagra Nitrate Combination Effect

In patients who inadvertently received the combination of nitrates and Viagra and who are manifesting a severe hypotensive response, nitrate and nitroprusside therapy should be immediately stopped. Depending on clinical circumstances, any of the following therapies should be considered alone or in combination:

• Placing the patient in Trendelenburg position;
• Aggressive fluid resuscitation;
• Judicious use of an intravenous a-adrenergic agonist, such as phenylephrine (Neosynephrine);
• An a- and b- adrenergic agonist (norepinephrine) for blood pressure support with the realization that this could exacerbate or lead to an acute ischemic syndrome;
• Intraaortic balloon counterpulsation.