Recommended Benzodiazepine Dosing for Seizures
For first-line treatment of seizures in adults and children, use lorazepam 0.05–0.1 mg/kg IV (maximum 4 mg per dose) or midazolam 0.2 mg/kg IM (maximum 6 mg per dose), with diazepam 0.1–0.3 mg/kg IV (maximum 10 mg per dose) as an alternative. 1, 2, 3
Adult Dosing
First-Line Options
Lorazepam IV/IM: 0.05–0.1 mg/kg (maximum 4 mg per dose), may repeat every 10–15 minutes if seizures continue 2
Midazolam IM: 0.2 mg/kg (maximum 6 mg per dose), may repeat every 10–15 minutes 2
Diazepam IV: 0.1–0.3 mg/kg every 5–10 minutes (maximum 10 mg per dose), administered over approximately 2 minutes 2, 3
The 2024 Epilepsia guidelines indicate that lorazepam, midazolam, and diazepam are all recommended as first-line agents, with 12 of 13 clinical practice guidelines recommending IV lorazepam specifically 1. Lorazepam is preferred for IV administration due to its prolonged duration of anticonvulsant activity compared to diazepam, which redistributes rapidly and may require repeat dosing within 15–20 minutes 2.
Maximum Total Dosing
For status epilepticus, diazepam may be repeated at 10–15 minute intervals up to a maximum total dose of 30 mg 3. If seizures persist after initial benzodiazepine therapy, second-line agents should be initiated rather than continuing to escalate benzodiazepine doses.
Pediatric Dosing
Age-Specific IV Dosing
Infants >30 days to children <5 years:
- Diazepam: 0.2–0.5 mg/kg slowly every 2–5 minutes, maximum 5 mg total 2, 3
- Midazolam: 0.05–0.1 mg/kg initial dose, total dose up to 0.6 mg/kg may be needed (usually not exceeding 6 mg) 4
Children 5 years or older:
- Diazepam: 1 mg every 2–5 minutes, maximum 10 mg total 2, 3
- Midazolam: 0.025–0.05 mg/kg initial dose, total dose up to 0.4 mg/kg may be needed (usually not exceeding 10 mg) 4
Lorazepam (all pediatric ages): 0.05–0.1 mg/kg IV/IM (maximum 4 mg per dose), may repeat every 10–15 minutes 2
IM Dosing for Pediatrics
When IV access is unavailable, midazolam 0.2 mg/kg IM (maximum 6 mg per dose) is the preferred route 2. This route achieves faster administration than IV in prehospital settings (median 7.3 minutes from EMS arrival for IM vs. 13.1 minutes for IV) 5.
Critical Administration Details
Timing and Technique
- Administer IV benzodiazepines slowly over 2–3 minutes to avoid respiratory depression and pain at the IV site 2, 4
- For midazolam IV, wait an additional 2–3 minutes after administration to fully evaluate sedative effect before repeating doses, as it takes approximately three times longer than diazepam to achieve peak EEG effects 4
- Diazepam should be followed immediately by a long-acting anticonvulsant (phenytoin/fosphenytoin) due to rapid redistribution 2
Common Pitfalls
Underdosing is prevalent: A 2025 study found that IV benzodiazepines were frequently underdosed (mean IV midazolam 2.1 mg vs. 8.7 mg for buccal administration) 6. Ensure weight-based dosing is calculated correctly.
Respiratory depression risk: All benzodiazepines increase apnea risk, especially when combined with other sedative agents or opioids. Be prepared to provide respiratory support regardless of route of administration 2. Monitor oxygen saturation continuously.
Route selection matters: Recent EMS data shows intranasal midazolam was associated with 39% higher odds of requiring additional benzodiazepine doses compared to IM administration (OR 1.39,95% CI 1.10–1.76) 5. When possible, prioritize IM or IV routes over intranasal for initial treatment.
Avoid rectal diazepam when alternatives exist: Rectal administration has slower onset (mean 68.3 seconds to administer vs. 50.6 seconds for intranasal midazolam) and is less socially acceptable 7.
Refractory Status Epilepticus
If seizures persist after appropriate first-line benzodiazepine dosing:
Midazolam continuous infusion: Loading dose 0.15–0.2 mg/kg IV, followed by continuous infusion starting at 1 mcg/kg/min (0.06 mg/kg/hr), increasing by 1 mcg/kg/min increments every 15 minutes (maximum 5 mcg/kg/min) until seizures stop 2
For neonates <32 weeks, initiate at 0.03 mg/kg/hr (0.5 mcg/kg/min); for neonates ≥32 weeks, use standard pediatric dosing 4.