Another antihypertensive combo approved

Combination approach

To meet the demand for the combination approach, Azor (amlodipine/olmesartan medoxomil, Daiichi Sankyo) was recently approved by the Food & Drug Administration as a once-daily oral tablet containing both a calcium-channel blocker and an angiotensin receptor blocker. As a calcium-channel blocker, amlodipine reduces total peripheral vascular resistance by preventing calcium entry into blood vessel walls. Olmesartan medoxomil keeps angiotensin II, a potent endogenous vasoconstrictor, from binding to its receptor. Together, the two medications relax blood vessels to lower blood pressure.

Azor is approved for use alone or as an add-on therapy for patients not adequately controlled on other antihypertensive agents, but it is not intended to be used as initial therapy. Tablets are available in four strengths (amlodipine/olmesartan medoxomil): 5/20 mg, 10/20 mg, 5/40 mg, and 10/40 mg.

Clinical studies

During clinical studies only edema occurred in >3% of patients treated with Azor and more frequently than placebo (22.1% versus 12.3%); edema is a known dose-dependent side effect of amlodipine. Significantly, African Americans (a population more likely to develop hypertension than any other racial or ethnic group) comprised 25% of the studied population, and the magnitude of blood pressure reduction was similar in both African Americans and non-African Americans.

As with other drugs that contain angiotensin receptor blockers, Azor should be avoided during pregnancy due to the risk of injury and death to the developing fetus. Increases in serum creatinine or blood urea nitrogen can be anticipated in individuals with renal artery stenosis.

In general, calcium-channel blockers should be used cautiously in patients with heart failure. Due to the risk of symptomatic hypotension, close medical supervision is suggested when initiating Azor in volume-depleted or sodium-depleted patients. Overall, no differences in safety or efficacy were observed between subjects ≥ 65 years of age and younger subjects.

When asked how Azor will likely fit into current clinical practice, Amy Seybert, Pharm.D., assistant professor of pharmacy and therapeutics at University of Pittsburgh School of Pharmacy and clinical cardiology pharmacist, commented, "It depends on the physician and patient comfort level.... Start with samples and reevaluate the drug therapy at a later point in time." She believes that the difficulty in attaining blood pressure goals is due to several things. "Patient unawareness, insurance coverage, and a disease that does not show any symptoms are all factors in treatment failure."

TIPS TO REMEMBER Azor

THE AUTHOR is a clinical writer based in the Philadelphia area.