Antidepressants and anti-clotting medication may raise bleeding risk

Heart attack patients are sometimes prescribed selective serotonin re-uptake inhibitors to treat depression. But if those SSRIs are taken in combination with anti-blood clotting drugs, those patients could be at greater risk for bleeding, a study finds.

The study, released Monday in the Canadian Medical Assn. Journal, followed 27,058 patients age 50 and older for a decade. The patients had all been diagnosed with acute myocardial infarction, otherwise known as a heart attack. Some were taking anti-clotting--also called antiplatelet--medications, which can help prevent blood clots formed by platelet cells by hindering the cells’ ability to clump.

The types of bleeding noted for the study were hemorrhagic stroke (the rupturing of a blood vessel in the brain), gastrointestinal bleeding, or any other type of bleeding that was treated during a hospital stay or that involved hospitalization.

When they were discharged from the hospital, more than half the patients were taking just aspirin as an antiplatelet therapy and about 3% of patients were taking an SSRI with antiplatelet therapy. Some were taking the antiplatelet medication clopidogrel, while others were taking both drugs. There are similar risks for bleeding for aspirin and clopidogrel when taken on their own.

But researchers found that taking an SSRI combined with any antiplatelet drug was linked with a higher risk of bleeding compared with taking aspirin alone. Mixing an SSRI with aspirin booted that risk up 42%, and combining an SSRI with a two-prong antiplatelet therapy increased the risk by 57%.

The authors noted that doctors must weigh the positives and negatives of giving heart attack patients SSRIs with antiplatelet medications. “The potential for drug interactions,” they wrote, “must be evaluated to guide the choice of medication.”