Vasodilators are widely used for treatment of congestive heart failure (CHF) that has not responded adequately to diuretics and digitalis. Vasodilator drugs redistribute blood volume in patients with heart failure, lowering pressure and reducing volume in the failing left ventricle, which leads to increased cardiac output, decreased pulmonary capillary wedge pressure, and improved exercise tolerance. Since the last Medical Letter review of this subject (Volume 26, page 115, 1984), some additional data have become available.

Fenoldopam mesylte (Corlopam - Neurex), a peripheral dopamine-1 (DA₁) agonist, has been approved by the FDA for parenteral use in lowering blood pressure. The manufacturer claims that, unlike other parenteral antihypertensive agents, fenoldopam not only lowers blood pressure but also maintains or improves renal function.

Hypertensive emergencies include hypertensive encephalopathy, intracranial hemorrhage with hypertension, aortic dissection, acute pulmonary edema with hypertension, acute cardiac ischemia with hypertension, malignant hypertension and severe hypertension after vascular surgery; hypertensive crisis due to pheochromocytoma or occurring during pregnancy is not discussed in this review. Although immediate reduction of blood pressure is necessary in hypertensive emergencies, an excessive decrease may cause stroke, myocardial infarction or visual changes. Most experienced clinicians aim...

BiDil (NitroMed), a fixed-dose combination of isosorbide dinitrate and hydralazine, was approved by the FDA for adjunctive use in the treatment of heart failure in black patients.Both drugs are oral vasodilators that have been used together off-label for many years to treat heart failure in patients not responding to other drugs.

Nesiritide, a recombinant human B-type natriuretic peptide (BNP), has been approved by the FDA of intravenous (IV) treatment of patients with decompensated congestive heart failure who have dyspnea at rest or with minimal exertion (New York Heart Association class IV).

The once-monthly, subcutaneously injected calcitonin gene-related peptide (CGRP) receptor antagonist erenumab-aooe (Aimovig) was approved by the FDA in 2018 for preventive treatment of migraine in adults. Now the FDA has added a new warning to its labeling about a risk of new-onset hypertension and worsening of preexisting hypertension associated with use of the drug. CGRP is a potent microvascular vasodilator; blocking or deleting it has produced hypertensive effects in animals.

The FDA has approved a lingual aerosol formulation of nitroglycerin (NitroMist – Akrimax) for acute relief of an attack or acute prophylaxis of angina pectoris. It is the second nitroglycerin lingual spray to become available in the US; Nitrolingual Pumpspray was approved in 1985. Most patients with angina use sublingual nitroglycerin tablets.

The FDA has approved Aurlumyn (Eicos Sciences), an IV formulation of the prostacyclin analog iloprost, to reduce the risk of digit amputation in adults with severe frostbite. Iloprost is the first drug to be approved by the FDA for treatment of severe frostbite; it has been used off-label for this indication in the EU and elsewhere for decades. In the US, iloprost is also available as an inhaled formulation (Ventavis) for treatment of pulmonary arterial hypertension.

The main purpose of vasopressors is to raise arterial blood pressure, while that of inotropes is to increase cardiac contractility. The choice of drugs is dictated by the clinical setting. Controlled trials comparing the efficacy and safety of these drugs are generally lacking.

The Medical Letter reported last year that sildenafil (Viagra - Pfizer) appeared to be effective for idiopathic pulmonary arterial hypertension (PAH), but confirmation from a controlled trial was needed. Now the results of such a study are about to be published, and the drug has been approved by the FDA for this indication under the trade name Revatio.