Pharmacologic drugs for controlled hypotension.

Due to the risks of transfusion reactions and the transmission of infectious diseases, there has been increased interest in measures to limit intraoperative blood loss and avoid the need for homologous transfusion. Controlled hypotension is one technique that has been used to limit intraoperative blood loss. Several drugs have been used alone or in combination for controlled hypotension, including the inhalational anesthetics, direct acting vasodilators such as nitroglycerin and nitroprusside, beta adrenergic antagonists, and calcium channel blockers. Various drugs available to the clinician for controlled hypotension are reviewed.