By Will Dunham WASHINGTON, July 7 (Reuters) - A class of drugs used by many people to treat depression may increase chances of gastrointestinal bleeding, although the risk remains low, Spanish researchers said on Monday. The research looked at antidepressants known as selective serotonin reuptake inhibitors, or SSRIs, and found that bleeding in the upper gastrointestinal tract is more common in people taking them than in those not doing so. The study indicated that taking acid-suppressing drugs cut the risk. The study also found a heightened risk for such bleeding in people taking Wyeth's <WYE.N> Effexor, also called venlafaxine, another type of antidepressant called a serotonin and norepinephrine reuptake inhibitor, or SNRI. The researchers stressed that such bleeding remains uncommon in people taking SSRIs or Effexor, and people taking them generally should continue to do it. "The risk in the general population taking SSRIs is very low -- 1 case in 2,000 patients treated -- and no specific action is required if the antidepressant is correctly indicated by a physician," Dr. Francisco de Abajo of the Spanish Agency for Medicines and Healthcare Products, who helped lead the study in the Archives of General Psychiatry, said by e-mail. "People with other relevant risk factors for GI bleeding should be considered for protecting their stomach with acid-suppressing agents. By no means, patients treated correctly with SSRIs should discontinue their treatment because of the fear (of having) a GI bleeding risk," de Abajo added. Such risk factors for gastrointestinal bleeding include a peptic ulcer or being elderly, he said. Some SSRIs include: Forest Laboratories Inc's <FRX.N> Celexa (citalopram); GlaxoSmithKline's <GSK.L> Paxil (paroxetine); Pfizer Inc's <PFE.N> Zoloft (sertraline); and Prozac, introduced by Eli Lilly and Co <LLY.N> in 1987 but now off patent and widely available generically as fluoxetine. De Abajo said he was involved in research published in 1999 suggesting an increased risk of GI bleeding in people taking SSRIs, but that other studies had questioned that finding. This study involved 1,321 people treated for upper gastrointestinal tract bleeding and about 10,000 people of the same age and sex who did not have such bleeding. It found that 5.3 percent of the people with such bleeding were taking SSRIs, while 3.0 percent of the people who did not have such bleeding were taking SSRIs. In addition, 1.1 percent of the people who were had bleeding were taking Effexor, compared to 0.3 percent of those who did not have bleeding. The risk was even higher in people taking SSRIs and other drugs harmful to the GI tract such as pain relievers known as non-steroidal anti-inflammatory drugs, or NSAIDs. SSRIs reduce symptoms of depression apparently by blocking the reabsorption of the brain chemical serotonin by certain nerve cells in the brain. The study was paid for by AstraZeneca Plc <AZN.L>, maker of the top-selling ulcer pill Nexium and Prilosec, which is now sold generically as omeprazole. (Editing by Cynthia Osterman)
