What is the recommended dosing for Ativan (lorazepam) in the management of seizures?

Lorazepam Dosing for Seizures

Standard Intravenous Dosing for Status Epilepticus

For adults with status epilepticus, administer lorazepam 4 mg IV slowly (2 mg/min), which may be repeated once after 10-15 minutes if seizures persist. 1

• The FDA-approved dose for adults ≥18 years is 4 mg given intravenously at a rate not exceeding 2 mg/min 1
• If seizures continue or recur after a 10-15 minute observation period, an additional 4 mg IV dose may be slowly administered 1
• Underdosing (using less than 4 mg in patients >40 kg) significantly increases progression to refractory status epilepticus (87% vs 62%, p=0.03) 2

Pediatric Dosing

For children with status epilepticus, use 0.1 mg/kg IV (maximum 4 mg per dose), which may be repeated every 10-15 minutes if needed. 3

• The American Academy of Pediatrics recommends 0.1 mg/kg IV (maximum 4 mg per dose) for pediatric status epilepticus 3
• Alternative dosing ranges of 0.05-0.10 mg/kg (maximum 4 mg) are also cited in pediatric guidelines 4, 3
• For convulsive status epilepticus specifically, 0.1 mg/kg IV (maximum 2 mg) may be repeated after at least 1 minute (maximum 2 doses) 4
• For non-convulsive status epilepticus, use 0.05 mg/kg (maximum 1 mg) IV, repeating every 5 minutes up to 4 doses 4

Alternative Routes When IV Access Unavailable

When IV access is not available, administer 0.2 mg/kg IM (maximum 6 mg per dose) in children, which can be repeated every 10-15 minutes. 3

• IM lorazepam is not preferred but may prove useful when an IV port is unavailable 1
• The IM dose is double the IV dose: 0.2 mg/kg (maximum 6 mg) versus 0.1 mg/kg (maximum 4 mg) IV 3
• Rectal administration (0.5 mg/kg up to 20 mg) has erratic absorption and is not recommended as first-line 4
• Never administer oral lorazepam for acute seizure management due to aspiration risk in the postictal period 3

Critical Safety Requirements

Equipment for airway management and artificial ventilation must be immediately available before administering lorazepam, as respiratory depression and apnea are the primary risks. 1

• Respiratory support must be readily available prior to IV administration 1
• Monitor oxygen saturation continuously, as apnea may occur up to 30 minutes after the last dose 5
• There is increased incidence of apnea when lorazepam is combined with other sedative agents 4, 3
• Flumazenil can reverse life-threatening respiratory depression but will also counteract anticonvulsant effects and may precipitate seizures 3, 5

Subsequent Management After Initial Dosing

If seizures persist after lorazepam, immediately administer a long-acting anticonvulsant such as phenytoin (18 mg/kg IV over 20 minutes) or fosphenytoin (20 mg phenytoin equivalents/kg at ≤150 mg/min). 4, 6

• Lorazepam is rapidly redistributed and seizures often recur within 15-20 minutes, necessitating long-acting anticonvulsant coverage 4
• Continue monitoring for seizure recurrence for at least 2 hours after initial lorazepam administration 3
• If seizures continue after benzodiazepine and phenytoin/fosphenytoin, consider phenobarbital (15-20 mg/kg IV over 10 minutes) 4
• For refractory status epilepticus, IV general anesthesia with pentobarbital, benzodiazepine infusion, or propofol should be initiated after establishing respiratory support 6

Common Pitfalls to Avoid

• Do not underdose: Using less than 4 mg in adults >40 kg significantly increases risk of progression to refractory status epilepticus 2
• Do not use oral lorazepam acutely: Aspiration risk in the immediate postictal period makes oral administration dangerous 3
• Do not delay long-acting anticonvulsant: Lorazepam alone is insufficient; phenytoin/fosphenytoin must follow immediately 4, 6
• Do not use flumazenil to reverse sedation: It will precipitate seizure recurrence and is only for life-threatening respiratory depression 3, 5