Which drug class is given preoperatively to relieve anxiety and provide antegrade amnesia?

• A. Benzodiazepines (Midazolam)
• B. Opioids (Fentanyl, Morphine, Dilaudid)
• C. Antiemetics (Zofran, Reglan, Pepcid)
• D. Vasodilators (Nitroglycerin)

Answer: (A)

Giving a preoperative anxiolytic with memory-blocking properties relies on a drug class that enhances GABA activity in the brain. Benzodiazepines do this by acting as positive allosteric modulators at the GABA-A receptor, increasing the inhibitory effect of GABA. This produces calming anxiety relief, sedation, and, importantly, antegrade amnesia—the patient is less likely to form new memories about events after administration. Midazolam is a classic example because it acts quickly, has a relatively short duration, and provides reliable amnesia with smooth IV onset, making it a common choice for preop use.

Opioids mainly provide analgesia and some sedation but do not consistently produce amnesia. Antiemetics prevent nausea, not memory loss. Vasodilators affect blood pressure and perfusion but have no role in anxiolysis or amnesia. Remember also that benzodiazepines can cause respiratory depression and oversedation, especially in the elderly or those with airway disease, and can be reversed with flumazenil if needed.