Which antiemetic can cause drowsiness and is often used for pre-operative sedation?

Midazolam is a benzodiazepine that is frequently used for its sedative effects, particularly in pre-operative settings. Its ability to induce drowsiness makes it a suitable choice for sedation prior to surgical procedures. This characteristic is due to its action on the central nervous system, where it enhances the effects of the neurotransmitter gamma-aminobutyric acid (GABA). By increasing GABA activity, it produces a calming effect, reducing anxiety and promoting sleepiness.

In the context of antiemetic agents, while other medications listed can help manage nausea and vomiting, they do not primarily serve the purpose of sedation. For example, ondansetron is specifically indicated for the prevention of nausea and vomiting, particularly in chemotherapy patients, and it does not induce drowsiness. Similarly, lorazepam, while it does have sedative properties, is not typically the first-line choice for pre-operative sedation and is more often used for its anxiolytic effects. Metoclopramide is an antiemetic that also increases gastrointestinal motility but lacks the sedative effects associated with midazolam.

Thus, midazolam stands out as the antiemetic that can effectively induce drowsiness and is commonly utilized for pre-operative sedation