Women, Particularly During Menses, More At Risk Than Men For Developing Prescription Drug-Induced Heart Problems.

2001 APR 5 - (NewsRx.com & NewsRx.net) -- Women are more at risk than men for developing a dangerous drug-induced heart condition which can lead to a potentially fatal cardiac arrhythmia, and this risk may be heightened during menstruation and ovulation.

These are the findings of research done at Georgetown University Medical Center and published in the March 14, 2001, issue of the Journal of the American Medical Association.

The heart condition, known as "prolonged QT interval," occurs when the time between certain waves (the "Q" and "T" waves) on an electrocardiogram (EKG) reading is abnormally prolonged. This is an indication that recharging of the heart between beats is occurring too slowly. A prolonged QT interval is dangerous because it can cause a potentially fatal heart arrhythmia known as Torsades de Pointes (TdP), a French phrase which literally means "twisting of the points," referring to the characteristic appearance of an EKG during the rhythm abnormality.

"The prolonged QT interval is really the first sign of trouble; it's an early warning sign that can be detected only with an EKG," according to Raymond Woosley, MD, PhD, associate dean for clinical research at Georgetown University Medical Center and principal investigator of the study. "After the prolonged QT interval has developed, it can lead to an abnormal heart rhythm that causes blackouts or even sudden death."

Some people have an inherited form of prolonged QT syndrome, and others develop the condition only after using certain medications. A list of prescription drugs that are known to cause prolonged QT syndrome and TdP - and more information about these two conditions - can be found at www.torsades.org.

Woosley explained that these studies, while providing valuable information about the factors contributing to the increased risk of TdP in women, cannot yet be used to make recommendations for changes in how to use the medications more safely. "Patients taking the drugs listed on the website should not become concerned and stop taking their medications, as the risk of TdP for most of these drugs is very small," he said. Woosley cautioned, however, that if patients develop symptoms of dizziness or fainting, they contact their physician as soon as possible and ask if their medication may be causing their symptoms.

"By understanding the role of sex hormones, we may someday be able to find ways to prevent these serious reactions to medications, but we're not there yet," said Woosley. "Four of the 10 drugs taken off the market over the last three years were ...