Safety profile of the proton-pump inhibitors.

The adverse effect profile of proton-pump inhibitors is presented. The proton-pump inhibitors are a well-tolerated class of drugs. The most common adverse events of headache, diarrhea, and nausea have been reported in fewer than 5% of patients treated with lansoprazole or omeprazole. The frequency of these adverse events with the two proton-pump inhibitors is comparable to that of placebo and histamine H2-receptor antagonists. Few clinically important interactions have been observed between proton-pump inhibitors and other drugs metabolized by the cytochrome P-450 system. The interaction potential should be considered when drugs with a narrow therapeutic window, such as phenytoin, warfarin, and theophylline, are used concomitantly with proton-pump inhibitors. Theoretical concerns about the consequences of chronic administration of proton-pump inhibitors, such as the impact of sustained hypergastrinemia on gastric morphology and the development of atrophic gastritis, have been dismissed. While increased gastrin levels are observed among patients taking proton-pump inhibitors, for the majority they remain within the normal range. After long-term use of the drugs, patients do not appear to be at increased risk of atrophic gastritis or gastric cancer. Helicobacter pylori infection, rather than acid suppression, may be the more important factor for the development of atrophic gastritis. Bacterial overgrowth and altered nutrient absorption resulting from sustained hypochlorhydria induced by chronic administration of proton-pump inhibitors have not been realized as clinical concerns. Not only are proton-pump inhibitors well tolerated during short-term administration, but there also do not appear to be clinically important adverse sequelae associated with their long-term use.