Sustained release and enteric coated NSAIDs: are they really GI safe?

Non-steroidal anti-inflammatory drugs (NSAIDs) have commonly been associated with upper gastrointestinal (GI) tract side effects including a high incidence of gastric and duodenal ulceration. Recent reports implicate NSAID use and mucosal injury in the small and large intestine. A trend in NSAID development has been an attempt to improve therapeutic efficacy and reduce the severity of upper GI side effects through modified release dosage forms of NSAIDs such as enteric-coating (EC) or sustained release (SR) formulations. It is possible that modified release formulations may increase the exposure of active drug to the mucosa distally to the duodenal bulb, and thereby increase toxicity to distal GI regions where the effects are difficult to monitor. A systematic literature review through Medline, Embase, and Index Medicus was made to identify toxicological effects induced by modified release formulations of NSAIDs in the small and large intestine. An analysis of the identified toxicological effects of these formulations was made. SR and EC NSAID use has been associated with both small and large intestinal bleeding, anaemia, strictures, ulcerations, perforations, and death. Modified release NSAIDs may cause significant morbidity in some patients. NSAID modified release delivery systems are not guarantors of GI safety. Since SR and EC NSAIDs are widely prescribed and some EC products are available without a prescription, heightened awareness of these toxicological manifestations in more distal sites of the GI tact may reduce morbidity.