MADRID, SPAIN. There have been sporadic case reports of bleeding disorders in patients taking selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), and fluvoxamine (Luvox). Now researchers at a Spanish medical research institute report that SSRIs do indeed increase the risk of upper gastrointestinal (stomach) bleeding. Their study involved 1651 cases of upper gastrointestinal bleeding occurring between April 1993 and September 1997. The cases were compared to 10,000 controls matched for age and sex.
The researchers found that people taking SSRIs were three times as likely to develop bleeding than were non-users. This corresponds to about one in 1300 users developing bleeding. They also found that patients who took both SSRIs and NSAIDs (non-steroidal anti-inflammatory drugs) had a 15 times greater risk of gastrointestinal bleeding than did people who took neither of the two classes of drugs. Even a combination of low-dose aspirin such as used for protection against heart attack and SSRIs significantly increased the risk of bleeding by a factor of seven.

The researchers conclude that SSRIs are associated with an increased risk of upper gastrointestinal bleeding and that this risk is vastly magnified if aspirin or NSAIDs are also taken. NOTE: This study was funded in part by Novartis, a major pharmaceutical company.
de Abajo, Francisco Jose, et al. Association between selective serotonin reuptake inhibitors and upper gastrointestinal bleeding: population based case-control study. British Medical Journal, Vol. 319, October 23, 1999, pp. 1106-09
Li Wan Po, Alain. Antidepressants and upper gastrointestinal bleeding: new results suggest a link. British Medical Journal, Vol. 319, October 23, 1999, pp. 1081-82 (editorial)