Methylnaltrexone
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Drug reference
Lorazepam
Benzodiazepine (intermediate-acting) · Anxiolytic/Sedative
Also known as Ativan, Loreta, Trapex, Lorax
START
Anxiety: 0.5 mg PO 2-3 times daily. Status epilepticus: 4 mg IV. Use lowest effective dose for shortest duration (2-4 weeks max for anxiety/insomnia)
TYPICAL MAX
10 mg/day (oral); short-term use only
STOP IF
Severe respiratory depression, paradoxical agitation, signs of dependence, jaundice
WATCH
Sedation level, respiratory rate (if IV or with opioids), falls risk (elderly), cognitive function, signs of dependence/tolerance, taper gradually (>/=2 weeks)
CDSCO approvedSchedule HATC N05BA06
KDIGO 2024 + manufacturer label
- ONSET
- 30min · PO: 30-60 min; IV: 1-5 min
- PEAK
- 2h · PO peak
- t½
- 15h · 10-20 hours
- DURATION
- 8h · 6-8 hours
EXCRETION
Renal (glucuronide)
route + CYP
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Avoid in pregnancy; risk of congenital malformations (cleft lip/palate) and floppy infant syndrome; contraindicated in first trimester
FDA category + note
Top interactionssee all 12 →
- MethylnaltrexoneSevereTextbookG&G 14e
- NalmefeneSevereTextbookG&G 14e
- NaloxoneSevereTextbookG&G 14e
- NaltrexoneSevereTextbookG&G 14e
Available in India
235 branded formulations. Look up specific brands in the Drugs workspace.
Mechanism
Positive allosteric modulator at GABA-A receptors, increasing the frequency of chloride channel opening and enhancing GABA-mediated inhibitory neurotransmission. Produces anxiolytic, sedative-hypnotic, muscle relaxant, and anticonvulsant effects.
Indications
Anxiety disorders (short-term relief)Insomnia (short-term)Status epilepticus (IV)Pre-operative sedation / anxiolysisAlcohol withdrawal syndromeAcute agitationChemotherapy-induced nausea/vomiting (adjunct)
Dosing
- Adult
- Anxiety: 0.5-2 mg PO/SL 2-3 times daily. Insomnia: 1-2 mg PO at bedtime. Status epilepticus: 4 mg IV (may repeat x1 after 10-15 min). Pre-op: 2-4 mg PO/IM/IV 1-2h before procedure. Alcohol withdrawal: 1-2 mg q1-4h PRN (CIWA-guided)
- Pediatric
- >12 years: 0.5-2 mg PO 2-3 times daily. Status epilepticus: 0.05 mg/kg IV (max 4 mg)
- Renal adjustment
- No adjustment needed; hepatically metabolized to inactive glucuronide
- Hepatic adjustment
- Reduce dose by 50%; avoid in severe hepatic impairment
- Geriatric
- Start 0.25-0.5 mg; increased sensitivity to sedation, falls, cognitive effects; max 2 mg/day
- Max dose
- 10 mg/day (oral); 8 mg/day IV (status epilepticus)
Pharmacokinetics
Onset
PO: 30-60 minutes; SL: 15-30 minutes; IV: 1-5 minutes; IM: 15-30 minutes
Peak effect
PO: 2 hours; IV: immediate; IM: 60-90 minutes
Duration
6-8 hours
Half-life
10-20 hours
Bioavailability
PO: ~85%; IM: ~90%
Protein binding
85-91%
Metabolism
Hepatic glucuronidation to inactive lorazepam glucuronide (no CYP involvement)
Excretion
Renal (primarily as glucuronide conjugate)
Contraindications
- Hypersensitivity to lorazepam or other benzodiazepines
- Acute narrow-angle glaucoma
- Severe respiratory insufficiency / sleep apnea
- Severe hepatic impairment
- Myasthenia gravis
- Concurrent use with sodium oxybate
- Pregnancy (especially first trimester)
Side effects
Common
SedationDrowsinessDizzinessWeaknessConfusion (especially elderly)AtaxiaMemory impairment (anterograde amnesia)Respiratory depression (high doses/IV)
Serious
- Respiratory depression / apnea (especially with opioids or IV)
- Dependence and withdrawal syndrome
- Paradoxical reactions (agitation, aggression)
- Suicidal ideation
- Severe hypotension
- Jaundice (rare)
Pregnancy & lactation
Pregnancy
Avoid in pregnancy; risk of congenital malformations (cleft lip/palate) and floppy infant syndrome; contraindicated in first trimester
Lactation
Excreted in breast milk; may cause sedation in infant; avoid if possible or use lowest dose
Drug interactions
Nalmefene
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Naloxone
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Naltrexone
Severe
Textbook
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: G&G 14e
Alfentanil
Severe
Database
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: DDInter
Benzhydrocodone
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Buprenorphine
Severe
Database
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: DDInter
Butorphanol
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Clozapine
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Codeine
Severe
Database
Increased rates of accidental overdose and death.
Caution is advised, especially for patients with a history of drug abuse.
Source: DDInter
Dextropropoxyphene
Severe
Database
Clinical effect not specified
Source: DDInter
Dezocine
Severe
Database
Clinical effect not specified
Source: DDInter
Related guidelines
Ask House about Lorazepam
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Harrison 22e, Katzung·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19