Recommended Dose and Frequency for Lorazepam IV Administration
For adult patients, the recommended IV lorazepam dose varies by indication: 4 mg given slowly (2 mg/min) for status epilepticus; 2 mg total or 0.02-0.05 mg/kg for sedation/anxiolysis; and 0.05 mg/kg (up to 4 mg) for preanesthetic use. 1
Adult Dosing by Indication
Status Epilepticus
- Initial dose: 4 mg IV given slowly (2 mg/min) for patients 18 years and older 1
- If seizures continue or recur after 10-15 minutes, an additional 4 mg IV dose may be administered 1
- Equipment to maintain patent airway must be immediately available 1
- Monitor vital signs, maintain unobstructed airway, and have ventilation equipment available 1
Sedation and Anxiety Relief
- Initial dose: 2 mg total or 0.02 mg/lb (0.044 mg/kg), whichever is smaller 1
- This dose is usually sufficient for most adult patients 1
- For patients over 50 years, do not exceed the recommended dose due to risk of prolonged sedation 1
- For patients requiring lack of recall for perioperative events, doses up to 0.05 mg/kg (maximum 4 mg) may be administered 1
- Administer 15-20 minutes before anticipated procedure for optimal effect 1
Preanesthetic Use
- Intramuscular dose: 0.05 mg/kg up to maximum of 4 mg 1
- Administer at least 2 hours before anticipated procedure for optimal effect 1
- Reduce doses of other CNS depressant drugs when used concomitantly 1
Administration Technique
- For IV administration, lorazepam must be diluted with an equal volume of compatible solution (Sterile Water for Injection, Sodium Chloride Injection, or 5% Dextrose Injection) 1
- Mix thoroughly by gently inverting container repeatedly until homogenous solution results (do not shake vigorously) 1
- Injection rate should not exceed 2 mg per minute 1
- Inspect solution for particulate matter and discoloration prior to administration 1
Special Populations
- Elderly patients: No dosage adjustment needed, but be aware of potential for more profound and prolonged sedation 1
- Hepatic disease: No dosage adjustment needed 1
- Renal disease: No adjustment needed for acute dose administration, but exercise caution with frequent doses over short periods 1
- Drug interactions: Reduce lorazepam dose by 50% when coadministered with probenecid or valproate 1
Pediatric Considerations
- Safety of lorazepam in pediatric patients has not been established per FDA labeling 1
- For status epilepticus in pediatric patients, the American Academy of Pediatrics suggests 0.05-0.10 mg/kg (maximum 4 mg per dose), which may be repeated every 10-15 minutes if needed 2
- Monitor oxygen saturation and be prepared to provide respiratory support due to increased incidence of apnea when combined with other sedative agents 2
Important Warnings and Precautions
- Respiratory depression is the most important risk, especially in status epilepticus treatment 1
- Airway patency must be assured and respiration monitored closely 1
- Prolonged sedation may occur, particularly with multiple doses 1
- Patients should not operate machinery or drive for 24-48 hours after receiving lorazepam 1
- Flumazenil may be administered to reverse life-threatening respiratory depression, but it will also counteract anticonvulsant effects and may precipitate seizures 2
Monitoring
- Monitor vital signs continuously during administration 1
- Watch for signs of respiratory depression 1
- For IV administration, ensure injection is not intra-arterial and that perivascular extravasation does not occur 1
- Recent research suggests that underdosing lorazepam in status epilepticus (less than 4 mg in adults) may lead to increased progression to refractory status epilepticus 3
Always ensure that equipment necessary to maintain a patent airway is immediately available prior to intravenous administration of lorazepam.