diphenhydramine + dexamethasone + famotidine

This is a combination of three drugs—diphenhydramine, dexamethasone, and famotidine—used primarily as a premedication regimen to prevent hypersensitivity or infusion-related reactions associated with certain chemotherapeutic agents (such as paclitaxel and oxaliplatin) and monoclonal antibody therapies.

• Diphenhydramine is a first-generation H1 receptor antihistamine that blocks histamine H1 receptors, reducing allergic symptoms such as itching, rash, and swelling. It also has sedative properties due to its central nervous system penetration.
• Dexamethasone is a synthetic glucocorticoid corticosteroid with potent anti-inflammatory and immunosuppressive effects. It acts by binding to the glucocorticoid receptor, modulating gene expression to suppress inflammatory responses.
• Famotidine is an H2 receptor antagonist that inhibits gastric acid secretion by blocking histamine H2 receptors in the stomach lining; it also contributes to reducing allergic-type reactions when used in combination with an H1 blocker.

This triple-drug regimen is commonly administered intravenously 30–60 minutes prior to chemotherapy infusions or biologic therapies for prophylaxis against acute hypersensitivity reactions. The combination targets multiple pathways involved in allergic responses (histaminergic via both H1 and H2 blockade plus corticosteroid-mediated suppression of inflammation), providing broad protection against infusion-related adverse events.