Lorazepam Sublingual Administration Dosing
For adults with seizure emergencies, sublingual lorazepam can be administered at doses of 0.5-2 mg, with most patients responding effectively to 1 mg doses, while pediatric patients require weight-based dosing of 0.05-0.10 mg/kg (maximum 4 mg per dose). 1, 2
Adult Dosing
Seizure Management
- Standard dose: 0.5-2 mg sublingually for prolonged (>5 minutes) or repetitive seizures (≥2 in 24 hours) 1
- Most commonly effective dose is 1 mg (median dose in clinical practice) 1
- Efficacy data: 66% of patients with repetitive seizures had no further seizure activity after treatment; 70% with prolonged seizures had cessation within 5 minutes 1
Anxiety and Agitation
- 0.5-1 mg orally/sublingually four times daily as needed (maximum 4 mg in 24 hours) 3
- Reduce to 0.25-0.5 mg in elderly or debilitated patients (maximum 2 mg in 24 hours) 3
- Oral tablets can be used sublingually (off-label use) 3
Delirium Management
- 1 mg subcutaneously or intravenously stat (up to 2 mg maximum) 3
- Can also be given orally or sublingually 3
- Use lower doses (0.25-0.5 mg) in older/frail patients or when co-administered with antipsychotics 3
Pediatric Dosing
Status Epilepticus
- 0.05-0.10 mg/kg intravenously given over approximately 2 minutes (maximum single dose: 5 mg) 3, 2
- May repeat every 10-15 minutes if needed 2
- Rectal administration: 0.5 mg/kg up to 20 mg (when IV access unavailable, though absorption may be erratic) 3
Sedation/Anxiolysis
- Intravenous: 0.05-0.10 mg/kg given over 2-3 minutes (maximum single dose: 5 mg) 3
- Peak effect occurs at 3-5 minutes 3
- Dose and observe, then redose every 3-5 minutes to avoid oversedation 3
- Oral: 0.25-0.50 mg/kg (maximum: 20 mg); children <6 years may require up to 1 mg/kg 3
Psychosis with Agitation
- Intramuscular/Intravenous: 0.05-0.15 mg/kg, may repeat hourly as necessary (maximum single dose: 5 mg) 3
Pharmacokinetic Considerations
Sublingual Absorption
- Complete bioavailability: Sublingual administration achieves 94-98% systemic availability, comparable to oral and intramuscular routes 4
- Time to peak concentration: 2.25-2.35 hours 4
- Absorption half-life: approximately 28-29 minutes 4
- Elimination half-life: 12.9 hours 4
- Sublingual route provides earlier onset of sedation and more amnesia compared to intramuscular administration 5
Clinical Advantages
- Sublingual lorazepam shows more rapid absorption than intramuscular injection, resulting in earlier drowsiness 5
- Avoids discomfort of injection 5
- Socially more acceptable than rectal administration for seizure emergencies 1
Critical Safety Warnings
Respiratory Depression Risk
- Increased incidence of apnea when combined with other sedative agents 3, 2
- Monitor oxygen saturation continuously 3, 2
- Be prepared to provide respiratory support regardless of route 3
- Flumazenil available for reversal of life-threatening respiratory depression, but note it will also reverse anticonvulsant effects and may precipitate seizures 3, 2
Adverse Effects
- Sedation: 31% of patients developed moderate/severe sedation in home seizure treatment 1
- No serious adverse events reported with home doses of 0.5-2 mg 1
- May cause drowsiness, unsteadiness, nausea, and paradoxical hyperactivity in children 6
- Subcutaneous injection may cause tissue irritation 3
Special Populations
- Elderly/debilitated patients: Reduce dose by 50% 3
- Renal impairment: Dose adjustment may be necessary 3
- COPD patients: Use lower doses due to respiratory depression risk 3
Practical Administration Tips
Storage and Access
- Most patients (98%) refrigerate lorazepam solution, often using coolers for portability 1
- However, 44% report refrigeration limits treatment access 1
- High patient satisfaction: 79% report feeling safer having emergency treatment available 1
Administration Technique
- Family caregivers typically administer treatment (88% of cases) 1
- Only 3% of patients self-administer 1
- Oral tablets can be placed sublingually for absorption 3