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# Lorazepam (representative benzodiazepine)
## Overview
Lorazepam is a short-acting benzodiazepine with anxiolytic, sedative, hypnotic, and anticonvulsant properties. It is primarily metabolized by glucuronidation, leading to fewer drug interactions compared to benzodiazepines metabolized by the cytochrome P450 system.
## Primary Indications
* Anxiety disorders
* Insomnia
* Status epilepticus (adjunct)
* Preoperative sedation
## Adult Dosing
* **Anxiety:** 0.5 mg to 2 mg orally 2 to 3 times daily. Maximum daily dose is typically 10 mg, but may vary based on indication and patient response.
* **Insomnia:** 2 mg to 4 mg orally at bedtime.
* **Status Epilepticus (IV/IM):** 2 mg to 4 mg IV or IM. May repeat in 5 minutes if needed, not to exceed 8 mg in a 12-hour period. For refractory cases, higher doses may be used under close medical supervision.
* **Preoperative Sedation (IM):** 2 mg to 4 mg IM 2 hours before surgery.
* **Conscious Sedation (IV):** 1 mg to 4 mg IV, titrated to effect.
Dosing for specific indications (e.g., ICU sedation) may differ and should follow institutional protocols.
## Pediatric Dosing
Dosing in pediatric patients is less established and should be individualized under close medical supervision.
* **Status Epilepticus (IV/IM):** 0.05 mg/kg per dose (max 2 mg) IV or IM. May repeat every 5-10 minutes to a maximum of 0.1 mg/kg or 4 mg total, whichever is less.
## Dose Adjustments
* **Hepatic Impairment:** Use with caution. Although metabolism is primarily glucuronidation, severe hepatic impairment may require dose reduction.
* **Renal Impairment:** No specific dose adjustment is usually necessary unless there is severe impairment, as the primary route of elimination is hepatic.
* **Elderly:** Initiate at the lower end of the adult dosage range (e.g., 0.5 mg orally twice daily) and titrate slowly, as elderly patients may be more sensitive to adverse effects.
## Contraindications
* Known hypersensitivity to lorazepam or other benzodiazepines.
* Acute narrow-angle glaucoma.
* Severe respiratory insufficiency.
* Severe hepatic insufficiency.
* Sleep apnea.
## Adverse Effects
* **Common:** Sedation, dizziness, fatigue, weakness, ataxia, decreased coordination.
* **Serious:** Respiratory depression, paradoxical reactions (e.g., excitation, aggression), anterograde amnesia, dependence, withdrawal symptoms upon abrupt discontinuation.
## Key Drug Interactions
* **CNS Depressants (e.g., alcohol, opioids, other sedatives):** Additive sedative and respiratory depressant effects. Co-administration should be avoided or managed with extreme caution, with dose reduction of one or both agents.
* **Valproic acid:** May increase lorazepam levels.
* **Theophylline and Aminophylline:** May reduce the sedative effects of benzodiazepines.
## Monitoring
* Level of consciousness, respiratory rate, and oxygen saturation, especially with IV administration or in combination with other CNS depressants.
* Signs of dependence or withdrawal if used long-term.
* Effectiveness for the primary indication.
## Clinical Pearls
* Lorazepam is available in oral, sublingual, intramuscular, and intravenous formulations.
* The IM route has reliable absorption. IV lorazepam is often used for acute seizure management and procedural sedation.
* Due to its relatively rapid onset and shorter duration of action compared to some other benzodiazepines, it is useful for acute anxiety and as a pre-anesthetic agent.
* Abrupt discontinuation after prolonged use can lead to withdrawal symptoms, including insomnia, anxiety, tremor, nausea, and potentially seizures. Tapering of the dose is recommended.
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*This information is intended for healthcare professionals. Always consult the current prescribing information and institutional guidelines for definitive guidance.*
