Midazolam (Versed) is a relatively short-acting benzodiazepine (“benzo”) which can be administered IV, PO, PR, and even within the neuraxial space to extend the duration/strength of the epidural/spinal block. For these reasons, it’s the most commonly used benzo in anesthesiology. Like all medications in this class, midazolam potentiates the effects of GABA (an inhibitory neurotransmitter) on the GABA(A) receptor by increasing the frequency of chloride flux. This results in neuronal hyperpolarization causing sedation, anterograde amnesia, relaxation, anticonvulsant activity, and anxiolysis.
As an anesthesiologist, I try to avoid pharmacologic anxiolysis in favor of a little “verbal anesthesia” through reassurance and humor. Reflexively giving IV midazolam to every pre-op patient is, in my opinion, a poor practice of medicine and definitely not a way to compensate for poor bedside manner. With that said, midazolam is a helpful adjunct for anxiolysis and amnesia for procedural sedation although I prefer agents like propofol, remifentanil, and dexmedetomidine. A small dose can also help treat emergence delirium from ketamine (my favorite!)
As an intensivist, I’m wary about utilizing benzos due to their unfavorable context-sensitive half times when run as infusions for sedation, deliriogenic effects (especially in the elderly), and risk for benzo tolerance/withdrawal. One must also be mindful about drug interactions leading to altered plasma concentrations as midazolam is metabolized by the P450 system! It’s certainly a medication that should be administered in low doses at first to see the subsequent physiologic effects before uptitrating. I’ve seen patients go completely apneic with only 0.5 mg!
Drop me a comment below with questions! 🙂