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# Lorazepam (Representative Benzodiazepine)
## Overview
Lorazepam is an intermediate-acting benzodiazepine used for its anxiolytic, sedative, anticonvulsant, and amnestic properties. It is preferred over some other benzodiazepines in hepatic impairment due to lack of active metabolites.
## Primary Indications
- Anxiety disorders (short-term)
- Preoperative sedation / procedural amnesia
- Status epilepticus (first-line when IV access available)
- Agitation (acute, in hospital settings)
- Alcohol withdrawal syndrome
## Adult Dosing
**Anxiety (PO):** 2–6 mg/day in divided doses; usual 2–3 mg/day. Max 10 mg/day.
**Insomnia (PO):** 2–4 mg at bedtime.
**Preoperative sedation (IM/IV):** 0.05 mg/kg (usual 2 mg total); max 4 mg.
**Status epilepticus (IV):** 0.1 mg/kg (usual 4 mg) IV push, may repeat once in 5–10 min. Max rate 2 mg/min.
**Agitation (IM):** 1–2 mg; may repeat in 1–2 hours.
**Alcohol withdrawal (PO/IV):** Varies by protocol; typically 1–4 mg every 1–4 hours based on symptom-triggered scoring (e.g., CIWA-Ar). Follow local protocol.
## Pediatric Dosing
**Anxiety/sedation (PO):** 0.05–0.1 mg/kg/dose (max 2 mg/dose) 2–4 hours before procedure.
**Status epilepticus (IV/IO):**
- Children 2–12 years: 0.1 mg/kg/dose (max 4 mg/dose)
- Adolescents: same as adult
May repeat once in 5–10 min if needed.
**Neonatal seizures (IV):** 0.05–0.1 mg/kg/dose over 2–5 minutes; may repeat once. Use with caution; risk of propylene glycol toxicity with repeated doses.
## Dose Adjustments
**Hepatic impairment:** Use cautiously; no dose adjustment needed for mild-to-moderate (no active metabolites) but increased sensitivity possible. Severe hepatic disease: reduce dose by 50% or avoid if encephalopathy present.
**Renal impairment:** No significant adjustment needed, but accumulation of inactive glucuronide metabolite may occur with prolonged use.
**Elderly or debilitated:** Start at 0.5–1 mg/day (PO) or 1 mg IV/IM; titrate slowly to avoid oversedation.
## Contraindications
- Acute narrow-angle glaucoma
- Severe respiratory insufficiency (e.g., sleep apnea, COPD exacerbation)
- Myasthenia gravis
- Known hypersensitivity to benzodiazepines
- Use with caution in substance use disorders, depression, and pregnancy (avoid in first trimester; not for prolonged use in third trimester due to neonatal withdrawal/ floppy infant syndrome)
## Adverse Effects
- CNS depression: sedation, dizziness, ataxia, confusion (especially elderly)
- Respiratory depression (dose-dependent, risk increased with IV push or combination with opioids)
- Paradoxical disinhibition (rare, more common in children/elderly)
- Tolerance, dependence, withdrawal syndrome with prolonged use
- IV use: pain, phlebitis; propylene glycol toxicity with high-dose/high-frequency IV infusions
## Key Drug Interactions
- **Opioids, alcohol, barbiturates, other CNS depressants:** additive sedation and respiratory depression – avoid or reduce dose.
- **Valproate:** may increase lorazepam levels (minor).
- **Probenecid:** reduces lorazepam clearance – may need dose reduction.
- **Clozapine:** increased risk of respiratory depression.
## Monitoring
- Sedation level (e.g., Richmond Agitation-Sedation Scale or RASS)
- Respiratory rate, oxygen saturation (especially during IV use or in elderly)
- Blood pressure (post-IV administration)
- Signs of tolerance, dependence, withdrawal (anxiety, insomnia, tremor, seizures)
- IV site for phlebitis
## Clinical Pearls
- Lorazepam is preferred over diazepam for IM injection (reliable absorption) and in hepatic impairment.
- For status epilepticus, IV lorazepam is first-line; if no IV access, IM midazolam is often preferred, but IM lorazepam is an option.
- Contains propylene glycol as a diluent; repeated high doses (>2 mg/hr) can cause metabolic acidosis, hyperosmolarity.
- Onset: PO (1–2h), IM (30–60 min), IV (1–5 min). Duration: 6–8h.
- Antidote: flumazenil (use cautiously – risk of seizures in benzodiazepine-dependent patients).
- Abrupt discontinuation after prolonged use (>2 weeks) may cause withdrawal; taper gradually (e.g., 25% per week).
> **Educational Disclaimer:** This information is for clinical reference and does not replace professional judgment. Always verify current prescribing information, local protocols, and manufacturer labeling before use. Dosing may vary based on institutional guidelines and patient-specific factors.
