SNOWMASS, COLO. — Don't hesitate to continue β-blocker therapy throughout pregnancy when the situation calls for it, Dr. Carole A. Warnes urged at a conference sponsored by the Society for Cardiovascular Angiography and Interventions.
“In practice I have been using β-blockers in pregnancy for 30 years. I've never had a significant problem with a baby after the mother has had a β-blocker,” declared Dr. Warnes, professor of medicine at the Mayo Clinic, Rochester, Minn.
“Do we worry about the growth of the fetus? Yes, and it needs to be monitored. At the time of delivery the baby may be bradycardic or may have hypoglycemia, but we can deal with that very easily. So for the woman who needs a β-blocker—for example, a patient with hypertrophic cardiomyopathy, or perhaps hypertension with a dilated aorta—we can use them and use them safely, and if it's better for the mother to continue then we do so,” she added at the conference, which was cosponsored by the American College of Cardiology.
There are four key principles to keep in mind when prescribing cardiovascular drugs in pregnancy: Stick to the ones with a long safety record, use the lowest effective dose and shortest duration, avoid multidrug regimens, and steer clear of agents labeled category D or X by the Food and Drug Administration, the cardiologist said.
In addition to many of the β-blockers, other cardiovascular drugs she listed as relatively safe in pregnancy include digoxin, calcium channel blockers, procainamide, hydralazine, methyldopa, and furosemide.
Agents that are not safe to use during pregnancy include statins, ACE inhibitors, angiotensin receptor blockers, phenytoin, and folic acid antagonists, including some antibiotics, Dr. Warnes said.