What is the recommended dose of lorazepam (Ativan) for seizure management in adults and pediatric patients?

Lorazepam Dosing for Seizure Management

Adult Dosing for Status Epilepticus

For adults (≥18 years) with status epilepticus, administer 4 mg of lorazepam IV slowly at 2 mg/min; if seizures persist or recur after 10-15 minutes, give a second 4 mg dose. 1

Initial Treatment Protocol

• The standard adult dose is 4 mg IV administered slowly over 2 minutes 1
• If seizures continue or recur after a 10-15 minute observation period, repeat with an additional 4 mg IV dose 1
• Experience with doses beyond two 4 mg administrations is very limited 1
• Equipment for airway management and ventilatory support must be immediately available before administration 1

Alternative Route When IV Access Unavailable

• IM lorazepam is not preferred but may be used when IV access is unavailable 1
• IM dosing follows the same 4 mg dose as IV administration 1
• Therapeutic levels are reached more slowly via IM route compared to IV 1

Critical Safety Monitoring

• Monitor vital signs continuously, particularly respiratory rate and oxygen saturation 1
• Maintain an unobstructed airway and have artificial ventilation equipment immediately available 1
• Respiratory depression is the most important risk, especially when combined with other CNS depressants 1
• Patients over 50 years may experience more profound and prolonged sedation 1

Pediatric Dosing for Status Epilepticus

For pediatric patients with status epilepticus, administer 0.1 mg/kg IV (maximum 4 mg per dose), which may be repeated every 10-15 minutes if seizures persist. 2, 3

Standard Pediatric Protocol

• The American Academy of Pediatrics recommends 0.05-0.10 mg/kg IV/IM with a maximum of 4 mg per dose 2, 3
• For convulsive status epilepticus specifically, use 0.1 mg/kg IV (maximum 2 mg), which may be repeated after at least 1 minute (maximum 2 doses) 2
• Doses may be repeated every 10-15 minutes if needed for continued seizures 2, 3
• The median effective dose in children under 12 years is 0.10 mg/kg, with 79% seizure cessation rate 4

Alternative IM Dosing for Pediatrics

• When IV access is unavailable, use 0.2 mg/kg IM (maximum 6 mg per dose) 2
• IM administration can be repeated every 10-15 minutes 2

Pediatric-Specific Safety Considerations

• The FDA label notes that safety in pediatric patients has not been fully established, and there are insufficient data to make formal dosage recommendations for patients under 18 years 1
• However, the American Academy of Pediatrics provides clear dosing guidance based on clinical experience 2, 3
• Respiratory support must be immediately available with continuous oxygen saturation monitoring 2, 3
• Risk of apnea increases significantly when combined with other sedatives 2, 3
• Paradoxical excitement or agitation may occur, especially in younger children 3

Non-Convulsive Status Epilepticus

• For non-convulsive status epilepticus, use 0.05 mg/kg (maximum 1 mg) IV, repeating every 5 minutes up to 4 doses 2
• This lower dosing reflects the different seizure type and reduced risk profile needed 2

Critical Post-Administration Management

Lorazepam is rapidly redistributed with seizures often recurring within 15-20 minutes, necessitating immediate administration of a long-acting anticonvulsant such as phenytoin or fosphenytoin. 2

Sequential Anticonvulsant Therapy

• If seizures persist after lorazepam, immediately administer phenytoin 18 mg/kg IV over 20 minutes or fosphenytoin 20 mg phenytoin equivalents/kg at ≤150 mg/min 2
• The benzodiazepine alone is insufficient for sustained seizure control 2, 1
• If seizures continue after benzodiazepine and phenytoin/fosphenytoin, consider phenobarbital 15-20 mg/kg IV over 10 minutes 2

Monitoring Duration

• Continue monitoring for seizure recurrence for at least 2 hours after initial lorazepam administration 2
• Be alert to excessive sedation adding to post-ictal impairment of consciousness, especially after multiple doses 1

Common Pitfalls and How to Avoid Them

Respiratory Complications

• Never administer lorazepam without immediately available airway equipment and ventilatory support 1
• The combination with other sedatives dramatically increases apnea risk 2, 3
• Flumazenil may reverse life-threatening respiratory depression but will also precipitate seizure recurrence 2, 3

Inadequate Seizure Control

• Do not rely on lorazepam alone—always prepare to administer long-acting anticonvulsants 2, 1
• Tachyphylaxis occurs with sequential doses, making lorazepam progressively less effective 4
• Lorazepam controlled only 82% of partial seizures with altered responsiveness compared to near-universal control of generalized tonic-clonic seizures 5

Administration Errors

• Never give anything by mouth to a patient who has just had a seizure due to aspiration risk in the postictal period 2
• Avoid IM diazepam (tissue necrosis risk), but IM lorazepam is acceptable when IV unavailable 3, 1
• Rectal lorazepam (0.5 mg/kg up to 20 mg) has erratic absorption and is not recommended as first-line 2

Special Population Considerations

• Elderly patients may require dose reduction due to more profound and prolonged sedation 1
• No dosage adjustment needed for renal or hepatic disease in acute dosing 1
• Patients should not operate machinery or drive for 24-48 hours after administration 1