Midazolam in a chronic alcoholic who binged, now vomiting with tremors

Why a benzodiazepine

Where midazolam fits

• Route and speed: Tintinalli's lists the IV onset as 2-5 min for midazolam, 5 min for diazepam and 5-20 min for lorazepam. IM absorption of midazolam and lorazepam is adequate. IM diazepam is erratic and not recommended. Midazolam is therefore useful when there is no IV access, or in an agitated, vomiting patient who can't take oral drugs (Tintinalli's Emergency Medicine, p. 1266).
• Vomiting: Tintinalli's recommends parenteral treatment, giving diazepam 10-20 mg IV or lorazepam 2-4 mg IV if the patient is vomiting. Midazolam can be used when these aren't available.
• Severe or refractory withdrawal (delirium tremens): Midazolam is used as a titrated bolus or infusion in the ICU. Tintinalli's escalation for benzodiazepine-refractory delirium tremens is phenobarbital or propofol, usually with intubation.
• Seizure with no IV access: IM midazolam is a reasonable option. I'm drawing that from general practice, and the textbook passages I pulled don't cover it.

Drawbacks of midazolam

• Short half-life: Its effect wears off quickly, which causes breakthrough symptoms and fluctuating levels. Harrison's notes that short-half-life agents must be given every 4 h to avoid abrupt level fluctuations that raise seizure risk. Long-acting agents (diazepam, chlordiazepoxide) self-taper. Diazepam and chlordiazepoxide give a 20-30 h effect through active metabolites.
• Liver disease: Chronic drinkers often have impaired hepatic function. Midazolam is cleared by CYP3A4 and can accumulate. Lorazepam, which is conjugated, is safer in significant liver disease. This point is from general pharmacology, not the textbook text I retrieved.
• Respiratory depression and aspiration: Vomiting plus sedation raises aspiration risk, and ongoing alcohol intoxication adds to the depressant effect. Titrate in small doses and monitor SpO2, respiratory rate and mental status. Give benzodiazepines for actual withdrawal signs, not just because the patient drank heavily.

Practical approach

1. Assess: vitals, temperature, glucose, electrolytes (K, Mg, phosphate), liver function, and signs of GI bleed, pancreatitis, infection or head injury. Score with CIWA-Ar.
2. Give thiamine before glucose, then other B vitamins.
3. Avoid routine IV fluids unless vomiting or bleeding has caused real volume loss (Harrison's). Treat the vomiting with an antiemetic such as ondansetron.
4. Use symptom-triggered dosing. Tintinalli's guide: CIWA-Ar above 15, repeat hourly until below 15. A score of 8-14 means repeat every 2 h until below 8. Fixed-dose regimens tend to undertreat or overtreat (Washington Manual).
5. Choose the drug:
   • Vomiting but stable: diazepam IV or lorazepam IV, then switch to oral once vomiting stops.
   • Midazolam IV/IM in small titrated doses: when you need fast onset or have no IV access. Convert to a longer-acting agent for maintenance.
   • Severe symptoms or delirium tremens: ICU, high-dose benzodiazepines, then phenobarbital or propofol if refractory.
6. Avoid dexmedetomidine as a sole agent. It doesn't act on GABA or glutamate, may mask autonomic signs without preventing seizures, and hasn't improved outcomes in trials (Washington Manual).

Recent evidence