cyclizine + metoclopramide

The combination of cyclizine and metoclopramide is generally not recommended for concurrent use due to their opposing mechanisms of action and potential interactions. Cyclizine is an antihistamine with anticholinergic properties, while metoclopramide is a prokinetic antiemetic that increases gastric emptying and blocks dopamine receptors. This combination has a moderate drug interaction classification, usually advisable to avoid except under special circumstances. The primary concern is that they should not be co-prescribed if the likely cause of nausea and vomiting is delayed gastric emptying (without obstruction), as cyclizine's anticholinergic actions may counteract metoclopramide's prokinetic effects. Clinical evidence on the combination's efficacy compared to placebo for chemotherapy-induced nausea and vomiting has not shown superiority in one study.