From the Guidelines
Lorazepam can be administered intramuscularly (IM) for certain indications, such as status epilepticus, with a dose of 0.05–0.10 mg/kg (maximum: 4 mg per dose) 1.
Key Considerations
- The IM route is an option when intravenous access is difficult or unavailable, and it is essential to monitor patients for potential side effects, including respiratory depression and sedation.
- The dose and administration of lorazepam via the IM route may vary depending on the specific indication, such as psychosis with agitation, adrenal insufficiency, or sedation/analgesia.
- It is crucial to follow the recommended dosages and guidelines to minimize the risk of adverse effects, such as hypotension, dystonic reactions, and prolonged QT interval.
Administration Guidelines
- For status epilepticus, lorazepam can be administered IM at a dose of 0.05–0.10 mg/kg (maximum: 4 mg per dose), which may be repeated every 10–15 min if needed for continued seizures 1.
- When administering lorazepam IM, it is essential to inject it deeply into a large muscle mass, such as the gluteal muscle or lateral thigh.
- Patients should be monitored closely for potential side effects, and respiratory support should be available if necessary.
Important Safety Information
- Lorazepam can cause respiratory depression, especially when combined with other sedative agents, and flumazenil may be administered to reverse life-threatening respiratory depression caused by lorazepam 1.
- The use of lorazepam via the IM route should be approached with caution in patients with increased intracranial pressure (ICP) or increased intraocular pressure.
From the FDA Drug Label
IM lorazepam is not preferred in the treatment of status epilepticus because therapeutic lorazepam levels may not be reached as quickly as with IV administration However, when an intravenous port is not available, the IM route may prove useful For the designated indications as a premedicant, the usual recommended dose of lorazepam for intramuscular injection is 0. 05 mg/kg up to a maximum of 4 mg. When given intramuscularly, lorazepam injection, undiluted, should be injected deep in the muscle mass.
Yes, Lorazepam (Ativan) can be administered intramuscularly (IM) 2. The recommended dose for intramuscular injection is 0.05 mg/kg up to a maximum of 4 mg for premedicant use. It is not the preferred route for treating status epilepticus, but it may be useful when an intravenous port is not available.
From the Research
Administration of Lorazepam
- Lorazepam can be administered through various routes, including oral, intravenous, and intramuscular 3.
- As a preanesthetic medication, lorazepam is available for oral, intravenous, or intramuscular administration, with a parenteral dose of 0.04 to 0.06 mg per kg being most effective 3.
Intramuscular Administration
- Lorazepam can be administered intramuscularly, and its absorption is rapid, with peak plasma levels reached at 1.15 hr after dosage 4.
- The absorption half-life of intramuscular lorazepam averages 14.2 min 4.
- Intramuscular lorazepam has an absolute systemic availability of 95.9% 4.
Comparison with Other Routes
- The pharmacokinetics of lorazepam are similar regardless of the administration route, with the elimination half-life being highly replicable within individuals 4.
- Intramuscular administration of lorazepam is compared to other routes, including intravenous, oral, and sublingual, in terms of absorption and bioavailability 4.
- Other studies also support the use of intramuscular midazolam as an alternative to intravenous lorazepam in certain situations [(5,6)].