Dr Francisco Jose De Abajo and his colleagues at the Agenciaespanola Del Medicamento in Madrid said the increased risk with the drugs known as Selective Serotonin Reuptake Inhibitors (SSRIS) was moderate and equivalent to a low dose of ibuprofen, an over-the-counter painkiller. But if SSRIS are taken with aspirin or non-steroidalanti-inflammatory drugs which are used to treat rheumatoid arthritis the risk increases significantly. Abajo and his team studied more than 1,600 people who had suffered upper gastrointestinal bleeding and compared them with 10,000 people who did not. They found that 3.1 pc of people with bleeding had been taking SSRIS.