Lorazepam Dosage in Pediatrics
For acute seizure control in pediatric patients, administer lorazepam 0.05-0.10 mg/kg IV/IM (maximum 4 mg per dose), with the option to repeat every 10-15 minutes if seizures persist. 1
Status Epilepticus Dosing
The FDA-approved dosing for status epilepticus is established only for patients ≥18 years, but pediatric guidelines provide clear weight-based recommendations 2:
- Initial dose: 0.05-0.10 mg/kg IV/IM
- Maximum single dose: 4 mg
- Repeat dosing: May repeat every 10-15 minutes if seizures continue
- Administration rate: Do not exceed 2 mg/min IV 2
Important caveat: The FDA label explicitly states "the safety of lorazepam in pediatric patients has not been established" 2. However, AAP guidelines from 2008 provide specific pediatric dosing recommendations that are widely used in clinical practice 1.
Recent evidence supports the 0.1 mg/kg dose achieves therapeutic concentrations of approximately 100 ng/mL and maintains levels >30-50 ng/mL for 6-12 hours 3. A second dose of 0.05 mg/kg can maintain therapeutic levels for approximately 12 hours without excessive sedation 3.
Sedation/Anxiolysis Dosing
For procedural sedation or anxiolysis 4:
- Prepubertal children (6-12 years): 0.25-0.50 mg
- Adolescents (≥13 years): 0.5-1 mg
- Adult dose (high BMI adolescents): 2 mg PO/IM
- May repeat: Every 30-60 minutes as needed
The FDA label recommends 0.05 mg/kg IM for preanesthetic use (maximum 4 mg) but notes insufficient data for patients <18 years 2.
Critical Safety Considerations
Respiratory depression is the most important risk, particularly in status epilepticus 2. Equipment for airway management must be immediately available before administration. Monitor oxygen saturation continuously and be prepared to provide ventilatory support.
Dose-dependent vital instability: Recent evidence demonstrates lorazepam administration causes significant vital instability (vasopressor need or intubation) with an odds ratio of 6.76 5. This effect is dose-dependent and prolongs ICU length of stay 5.
Increased apnea risk when combined with other sedatives, particularly opioids 1. Have flumazenil available, though note it will reverse anticonvulsant effects and may precipitate seizure recurrence 1.
Conversion from IV Midazolam (for Withdrawal Management)
When converting from continuous IV midazolam >7 days duration 6:
- Calculate 24-hour midazolam dose
- Divide by 12 to determine daily lorazepam dose (lorazepam is 2x more potent with 6x longer half-life)
- Divide calculated dose by 4 and give every 6 hours orally
- Wean by 10-20% per day, or gradually increase dosing interval (every 8h → 12h → 24h → every other day)
Efficacy Evidence
Lorazepam vs. diazepam: A 2014 RCT of 273 pediatric patients found no difference in efficacy (72.1% vs 72.9% seizure cessation) or safety (16.0% vs 17.6% requiring assisted ventilation) between diazepam and lorazepam 7. This challenges the preferential use of lorazepam over diazepam.
Underdosing consequences: Patients receiving <4 mg lorazepam had significantly higher progression to refractory status epilepticus (87% vs 62%, p=0.03) compared to those receiving the full 4 mg dose 8. This strongly supports guideline-recommended dosing for patients >40 kg.
Route-Specific Considerations
- IV preferred for status epilepticus due to rapid therapeutic levels 2
- IM acceptable when IV access unavailable, though therapeutic levels achieved more slowly 2
- Intranasal route: 0.1 mg/kg (max 4 mg) demonstrated non-inferiority to IV in one study 9
- Sublingual: May be effective for home rescue therapy in adults, but pediatric data limited 10
Administration technique: Dilute with equal volume of compatible solution before IV use. Inject slowly with repeated aspiration to avoid intra-arterial injection or extravasation 2.
Maximum Daily Dosing
No specific maximum daily dose is established in pediatric guidelines. The FDA label notes "experience with further doses of lorazepam is very limited" beyond initial treatment 2. Clinical judgment should guide repeated dosing based on seizure control, sedation level, and respiratory status.