Patients' Genes Can Be Bad Medicine

THURSDAY, Jan. 12 (HealthDay News) -- Many people take drugs that can be affected by their individual genes and trigger adverse reactions, a new study finds.

The study of 607 outpatients at three primary-care sites found that 29 percent of the patients had taken at least one of 16 drugs that can be affected by a person''s genetics. These drugs included the antidepressant fluoxetine, the beta blocker metoprolol, the high blood pressure drug diltiazem and the anticoagulant warfarin.

Genetic variations in people who take these and some other drugs can change the properties of enzymes that break down drugs or mark them for excretion. This can lead to adverse reactions such as gastrointestinal bleeding, kidney impairments, dizziness, slowed heart beat, low blood pressure and cerebrovascular hemorrhages.

"Until now, researchers looking at the role of genetic variation in drug effects have focused mainly on toxic drugs used by specialists treating cancer or HIV infection," researcher Howard L. McLeod, director of pharmacology at Washington University School of Medicine in St. Louis, said in prepared statement.

"We know that some of the drugs commonly used in the family practice setting can cause adverse reactions in people who have certain genetic variations, so we measured just how often these drugs are used," McLeod said.

The findings suggest that pharmacogenomics -- the study of the interaction between drugs and genes -- may be able to benefit a large number of people and reduce health-care cost while improving the quality of treatment, McLeod and his colleagues noted.

The study appears in the January issue of the journal Pharmacogenomics.

More information

The American Medical Association has more about pharmacogenomics.

Robert Preidt

SOURCE: Washington University School of Medicine, news release, Jan. 4, 2006

Last Updated: Jan. 12, 2006