Lorazepam Dosing for Acute Seizures and Status Epilepticus
For adults with active seizures or status epilepticus, administer lorazepam 4 mg IV at 2 mg/min immediately; if seizures persist after 10–15 minutes, give a second 4 mg dose (total 8 mg maximum). 1, 2
Adult Dosing Protocol
- Initial dose: Lorazepam 4 mg IV push at a rate of 2 mg/min for any patient actively seizing 1, 2, 3
- Repeat dose: If seizures continue or recur after 10–15 minutes, administer an additional 4 mg IV slowly 1, 2
- Maximum total: 8 mg (two 4 mg doses); do not exceed this without escalating to second-line agents 2, 1
This regimen achieves seizure termination in approximately 65% of patients with status epilepticus, which is superior to phenytoin alone (44%) and diazepam (56%) 4, 5, 3
Pediatric Dosing Protocol
Convulsive Status Epilepticus
- Initial dose: 0.1 mg/kg IV (maximum 4 mg per dose) 6, 7
- Repeat: May repeat after at least 1 minute if needed, up to a maximum of 2 doses 6
- Alternative dosing: 0.05–0.10 mg/kg IV/IM (maximum 4 mg), repeatable every 10–15 minutes 6
Non-Convulsive Status Epilepticus
- Lower dose: 0.05 mg/kg IV (maximum 1 mg per dose) 6
- Repeat: May repeat every 5 minutes up to a maximum of 4 doses 6
Evidence Supporting Pediatric Dosing
- A 0.1 mg/kg dose achieves therapeutic concentrations of approximately 100 ng/mL and maintains levels >30–50 ng/mL for 6–12 hours 7
- A second dose of 0.05 mg/kg maintains therapeutic levels for approximately 12 hours without excessive sedation 7
- The mean effective dose in pediatric studies was 0.11 mg/kg (range 0.03–0.22 mg/kg) 8
- Lorazepam stopped status epilepticus in 79% of pediatric patients and diminished intensity in an additional 4% 9
Critical Pre-Administration Requirements
Before giving lorazepam, ensure the following equipment is immediately available: 1, 2
- Bag-valve-mask ventilation capability
- Oxygen and suction
- Airway management equipment (intubation supplies)
- Continuous pulse oximetry and cardiac monitoring 3
Respiratory depression is a predictable adverse effect that may require intervention, particularly when lorazepam is combined with other sedatives or opioids 6, 2
When to Escalate to Second-Line Agents
If seizures persist after two doses of lorazepam (total 8 mg), immediately escalate to a second-line anticonvulsant—do not give additional lorazepam. 2, 1
Second-Line Options (in order of safety profile):
- Valproate 20–30 mg/kg IV over 5–20 minutes: 88% efficacy, 0% hypotension risk 2, 4
- Levetiracetam 30 mg/kg IV over 5 minutes: 68–73% efficacy, minimal cardiovascular effects 2, 4
- Fosphenytoin 20 mg PE/kg IV at ≤150 PE/min: 84% efficacy, 12% hypotension risk (requires cardiac monitoring) 2, 4
- Phenobarbital 20 mg/kg IV over 10 minutes: 58.2% efficacy, higher respiratory depression risk 2, 4
Special Population Considerations
Elderly Patients (>50 years)
- Consider lower initial doses due to increased sensitivity 3
- The standard 2 mg IV dose may suffice for sedation in patients over 50 years 1
Patients with Renal Disease
- No acute dose adjustment needed for single doses 1
- Exercise caution if frequent doses are given over short periods 1
Patients with Hepatic Disease
- No dosage adjustment required 1
Drug Interactions
- Reduce lorazepam dose by 50% when coadministered with probenecid or valproate 1
- May need to increase dose in females taking oral contraceptives 1
Concurrent Management While Administering Lorazepam
Simultaneously search for and treat reversible causes: 2, 3
- Hypoglycemia: Check fingerstick glucose immediately; give 50 mL of 50% dextrose IV if present 2, 3
- Hyponatremia: Most common electrolyte disturbance precipitating seizures 2
- Hypoxia: Ensure adequate oxygenation 2
- Drug toxicity or withdrawal: Especially alcohol, benzodiazepines, barbiturates 2
- CNS infection: Consider meningitis/encephalitis 2
- Acute stroke or intracerebral hemorrhage: Particularly in patients >40 years 2
Common Pitfalls to Avoid
- Do NOT give lorazepam if the seizure has already stopped spontaneously—a single self-limiting seizure does not require acute benzodiazepine treatment 2
- Do NOT skip to third-line anesthetic agents (midazolam infusion, propofol, pentobarbital) until benzodiazepines and one second-line agent have failed 2
- Do NOT delay anticonvulsant administration to obtain neuroimaging—CT can be performed after seizure control is achieved 2
- Do NOT use neuromuscular blockers alone (e.g., rocuronium)—they only mask motor manifestations while allowing continued electrical seizure activity and brain injury 2
Monitoring After Administration
- Continuous oxygen saturation monitoring throughout treatment 6, 2
- Apnea can occur up to 30 minutes after the last dose 2
- Respiratory depression requiring intubation is more common in children <2 years 8
- Risk of respiratory depression increases substantially when combined with opioids or other sedatives 2, 6
Definition of Status Epilepticus
Status epilepticus is defined as:
- Any seizure lasting ≥5 minutes, OR
- Recurrent seizures without return to baseline consciousness between episodes 2, 10
The operational definition was shortened from 30 minutes to 5 minutes because delayed treatment increases morbidity/mortality to 5–22% overall and up to 65% in refractory cases 2
Prognosis and Importance of Rapid Treatment
- Overall mortality for status epilepticus: 5–22% 2
- Mortality in refractory status epilepticus: ≈65% 2
- Lorazepam is significantly superior to phenytoin in head-to-head comparison (65% vs 44% success, p=0.002) 5, 4
- Lorazepam has a longer duration of action than diazepam, making it the preferred benzodiazepine 5, 2