Which agent used for the treatment of GERD has a high risk of drug interactions?

Cimetidine (Tagamet) is associated with a high risk of drug interactions primarily due to its ability to inhibit several cytochrome P450 enzymes in the liver. This inhibition can lead to altered metabolism of many other medications, thereby increasing the serum levels of these drugs and potentially causing toxicity. Because cimetidine competes with other medications for metabolism, it can significantly affect the pharmacokinetics of numerous drugs that are metabolized by the same liver enzymes.

In contrast, omeprazole, ranitidine, and lansoprazole tend to have a lower risk of significant drug interactions. Omeprazole and lansoprazole are proton pump inhibitors that also have some potential to interact with other drugs, but less so than cimetidine. Ranitidine is an H2 receptor antagonist and generally poses an even lower risk for drug interactions. Therefore, cimetidine stands out among these options for its notable propensity to interact with a wide variety of medications, making it important for healthcare providers to monitor for potential drug-drug interactions when patients are prescribed this agent.