SIDE-EFFECTS WITH OMEPRAZOLE - A SURVEY B Y THE FRENCH ADR REGIONAL MONITORING CENTERS

Omeprazole has been marketed in France since 1989, for the healing of peptic ulcers, erosive reflux osophagitis and the Zollinger Ellison sy ndrome. It is a proton pump inhibitor which inhibits the acid secretio n in the stomach. In the majority of the clinical trials, omeprazole h as been found to be well tolerated : headache, dizziness, skin rash, c onstipation have just been noted. Since September 1989, 143 adverse re actions have been reported to pharmacovigilance centres and Astra Fran ce : 37 neurological and psychiatric side effects, especially confusio n in patients with hepatic diseases and/or advanced age; 35 cutaneous reactions, generally rash and urticaria; 22 hematological effects : le ucopenia and agranulocytosis have been reported but the relation with omeprazole is very uncertain; 10 gastrointestinal effects, generally d iarrhoea, nausea, vomiting and abdominal pain; 8 hepatic disorders, es pecially moderate elevation of aminotransferases. This study confirms the safety of this drug, during short treatment; the frequency of noti fied adverse effects is about 1/12 200 treatments of 4 weeks. The mini stry of health, has decided, in november 1991, to inform the prescribe rs of this potential toxicity of omeprazole, particulary, of the risk of confusion, hepatotoxicity and leucopenia.