NSAIDs – Impaired Metabolism (GS191 Genetic Marker)
Summary The GS191 genetic marker is associated with impaired metabolism of NSAIDs (non-steroidal anti-inflammatory drugs), potentially leading to increased toxicity or reduced clearance of these drugs. If this marker is present, NSAID use should be approached with caution or avoided, depending on the specific drug and the patient’s overall clinical context. What is GS191? The GS191 marker is a pharmacogenetic variant identified in certain genetic screening platforms, such as GeneSight and other pharmacogenomic tests. It is not a standard single nucleotide polymorphism (SNP) identifier like rs1057910 but is more likely a proprietary label used to summarize one or more relevant variants—particularly those that impact the metabolism of NSAIDs. This marker typically reflects altered function in cytochrome P450 enzymes, especially: CYP2C9 , the primary enzyme responsible for metabolizing many NSAIDs including ibuprofen, diclofenac, and celecoxib. CYP2C8 and CYP3A4 , which also cont...