Dexamethasone–ondansetron admixture

A dexamethasone–ondansetron admixture is a pharmaceutical combination consisting of the corticosteroid dexamethasone and the 5-HT3 receptor antagonist ondansetron. This combination is widely used in clinical practice for the prevention of chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV) (StatPearls, 2023). Dexamethasone acts by binding to glucocorticoid receptors, which may reduce emesis by inhibiting prostaglandin synthesis or decreasing blood-brain barrier permeability to emetogenic toxins (PubMed, PMID: 11149330). Ondansetron works by blocking serotonin (5-HT3) receptors on vagal nerve terminals in the gut and in the chemoreceptor trigger zone of the brain (PubChem, CID 4595). While these drugs are often administered together, the stability of the admixture depends on the specific concentrations and the intravenous fluid used, such as 0.9% sodium chloride or 5% dextrose (Journal of Oncology Pharmacy Practice, 2004). This entry describes a drug-drug combination rather than a single biological target molecule. The use of this admixture is a standard of care in many oncology protocols to improve patient quality of life during treatment. Clinicians must monitor for potential side effects such as QT interval prolongation and metabolic disturbances.

Other names

Dexamethasone and ondansetron combinationOndansetron and dexamethasone mixtureDexamethasone-ondansetron co-administration

Dexamethasone acts as a glucocorticoid receptor agonist, while ondansetron acts as a selective 5-HT3 receptor antagonist. Together, they provide synergistic antiemetic effects by targeting both central and peripheral pathways of the emetic reflex (StatPearls, 2023).