New Hypertension Drug Poses Breathing Risks

Nebivolol (BYSTOLIC), approved by the Food and Drug Administration (FDA) in December 2007 to treat hypertension, is one of a class of drugs called beta-blockers. Research has suggested that nebivolol does not exhibit any unique qualities for treating hypertension and is comparable to other drugs in the class for this indication, many of which are available as lower-priced generic drugs. Because it is a relatively newly approved drug, Worst Pills, Best Pills News recommends not taking nebivolol until 2015, when more may be known about its risks. Furthermore, the drug may pose specific risks to patients with asthma or chronic obstructive pulmonary disease (COPD).

Breathing difficulties

Nebivolol has been described in medical journal articles as being a “beta-one selective beta-blocker,” similar to the drugs atenolol (TENORMIN) and metoprolol (LOPRESSOR, TOPROL XL). A beta-one selective beta-blocker specifically targets the beta-one receptors, which are located in the heart and work to modulate heart rate and the strength of the heart’s contraction. When beta-one receptors are blocked, a lower heart rate and blood pressure results, desired effects in patients with hypertension.

Yet while nebivolol is described as selectively targeting beta-one receptors, pre-marketing studies indicated that this selectivity only applies to low doses of less than or equal to 10 milligrams (mg) daily. At doses higher than 10 mg, nebivolol loses its selectivity and blocks the beta-two receptors as well. However, the FDA has approved dosages ranging from 5 mg to 40 mg daily.

This lack of selectivity is harmful for those with asthma or COPD because nonselective beta-blockers (such as labetalol [NORMODYNE, TRANDATE], propranolol [INDERAL, INDERAL LA]) or doses of nebivolol greater than 10 mg) can have adverse effects on breathing. These drugs inhibit smooth muscle relaxation throughout the body, including in the upper airway where they impair bronchial and bronchiolar dilation.

Because those predisposed to airway constriction due to asthma or COPD may experience airway spasms and difficulty breathing with nonselective beta-blockers, they may be better off using a truly selective beta-one receptor blocker for hyptertension treatment. Patients with asthma or COPD should note that atenolol and metoprolol are functionally beta-one selective.

What You Can Do

If you have high blood pressure, the best ways to reduce or eliminate the need for medication are to improve your diet, lose weight, exercise, and decrease salt and alcohol intake. Mild hypertension can be controlled through proper nutrition and exercise.

If these measures do not sufficiently lower your blood pressure and your doctor says that you need medication, hydrochlorothiazide (ESIDRIX, HYDRODIURIL, MICROZIDE), a water pill (diuretic), is the drug of choice. Start with a low dose of 12.5 mg daily.

If you are already taking nebivolol, do not stop taking it without consulting your doctor. This is especially important in patients with coronary artery disease. The FDA-approved label warns that “severe exacerbation of angina, myocardial infarction and ventricular arrhythmias has been reported in patients with coronary artery disease following the abrupt discontinuation of therapy with beta-blockers.”

Among the most common adverse events of nebivolol are headache and fatigue. As noted on the drug label, do not take nebivolol if you have:

• heart failure and are in the intensive care unit or need medicines to keep up your blood circulation;
• a slow or irregular heartbeat (in which the heart skips beats); or
• severe liver damage.

Do not take this drug if you have asthma or COPD.

Talk to your doctor about possibly switching to a more-established drug in the beta-blocker family if you have not adequately responded to a water pill alone.