Safety profile of proton pump inhibitors according to the spontaneous reports of suspected adverse reactions

[corrected] To evaluate similarities and differences in safety among proton pump inhibitors (PPIs) under the usual conditions of prescription.A search of spontaneous reports on adverse reactions associated with these drugs and registered between January 1, 2004 and December 31, 2004 was undertaken in the Spanish Pharmacovigilance System Database. We compared the frequency of reports with the consumption of PPIs, and analyzed the organ and system distribution for each PPI. Of the organ and system groups more commonly affected, diarrhea, myalgia, abnormal vision and hepatitis were selected for further analysis.Nearly 8 times more reports for omeprazole compared to other drugs were found but a similar difference was observed in their consumption. Skin and appendage disorders were more frequently reported for omeprazole and rabeprazole, the urinary, female reproductive and endocrine systems for lansoprazole, musculoskeletal for omeprazole and esomeprazole, vision for pantoprazole, rabeprazole and esomeprazole, gastrointestinal tract for omeprazole and lansoprazole and liver and biliary systems for omeprazole, lansoprazole and pantoprazole. Myalgia appears more often in younger patients than diarrhea, abnormal vision or hepatitis and shows longer periods of latency and recovery. The four adverse reactions analyzed were mainly reversible.A direct relationship was found between consumption and the number of reports. Some organ and system groups were affected by more than one PPI and this showed a specific pattern of group toxicity to these pharmacological agents. Some reports involved only lansoprazole and these require further analysis.