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# Lorazepam
## Overview
Lorazepam is a high-potency, intermediate-acting benzodiazepine. It acts as a positive allosteric modulator of the $\text{GABA}_A$ receptor, enhancing the inhibitory effects of GABA. It is characterized by a slower onset of action compared to diazepam (but longer duration) and is conjugated directly (glucuronidation), making it safer in patients with hepatic impairment.
## Primary Indications
* Anxiety disorders (short-term management).
* Status epilepticus (first-line).
* Perioperative sedation and anesthesia induction.
* Acute alcohol withdrawal syndrome.
* Insomnia (short-term).
## Adult Dosing
* **Anxiety:** 1–3 mg orally per day in divided doses. Maximum: 10 mg/day.
* **Insomnia:** 2–4 mg orally at bedtime.
* **Status Epilepticus:** 4 mg IV bolus; may repeat once after 10–15 minutes if seizures persist.
* **Acute Alcohol Withdrawal:** 2–4 mg IV/IM every 2–4 hours as needed, titrated to symptom control.
## Pediatric Dosing
* **Status Epilepticus:** 0.05–0.1 mg/kg IV/IO (max single dose: 4 mg). May repeat every 10–15 minutes if needed.
* **Sedation/Pre-op:** 0.05 mg/kg IV/IM (max: 2 mg).
* *Note: Dosing can vary by institutional status epilepticus protocol; always verify local weight-based guidelines.*
## Dose Adjustments
* **Hepatic Impairment:** Safe for patients with cirrhosis or hepatitis as it undergoes minimal oxidative metabolism, but exercise caution due to increased sensitivity.
* **Renal Impairment:** No specific adjustment required, but patients are more sensitive to drug accumulation.
* **Geriatrics:** Reduce starting dose by 50%. Use with extreme caution due to risk of falls and delirium.
## Contraindications
* Known hypersensitivity to benzodiazepines.
* Acute narrow-angle glaucoma.
* Severe respiratory insufficiency.
* Sleep apnea (relative).
* Myasthenia gravis.
## Adverse Effects
* **Common:** Sedation, dizziness, ataxia, weakness, confusion.
* **Severe:** Respiratory depression, paradoxical reactions (more common in children/elderly), physical dependence, and withdrawal symptoms upon abrupt cessation.
* **IV-specific:** Hypotension, injection site reactions.
## Key Drug Interactions
* **CNS Depressants:** Avoid concomitant use with opioids, alcohol, and other sedatives due to additive risk of fatal respiratory depression (Black Box Warning).
* **Valproic Acid:** May inhibit lorazepam metabolism, increasing serum concentrations.
* **Scopolamine:** Risk of increased sedation, hallucinations, and irrational behavior.
## Monitoring
* **Respiratory Status:** Monitor RR, pulse oximetry, and mental status throughout IV administration.
* **Hemodynamics:** Monitor blood pressure during rapid IV infusion.
* **Long-term:** Monitor for signs of tolerance, misuse, or dependence.
## Clinical Pearls
* **Formulation Warning:** Lorazepam injection contains polyethylene glycol and propylene glycol, which can cause metabolic acidosis if administered via high-dose continuous infusion.
* **Storage:** IV vials must be refrigerated; do not use if cloudy or discolored.
* **Reversal:** Flumazenil is a competitive antagonist but is rarely recommended in chronic users due to the risk of precipitating seizures.
* **Paradoxical Effects:** Disinhibition or agitation is occasionally observed and may require discontinuation.
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**Disclaimer:** This information is for educational purposes only. Always verify dosing, contraindications, and drug interactions against institutional protocols and the most current, manufacturer-provided prescribing information (package insert) before clinical use.
