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
Chlordiazepoxide
Long-acting benzodiazepine · Anxiolytic
Also known as Chlordiazepoxide hydrochloride, Librium
START
Alcohol withdrawal: 50 mg PO q4–6h, taper. Anxiety: 5–10 mg PO TID-QID
TYPICAL MAX
300 mg/day (alcohol withdrawal day 1)
STOP IF
Respiratory depression, severe ataxia/falls, or dependence
WATCH
Sedation, cognition (elderly), falls, respiratory status, taper plan
CDSCO approvedATC N05BA02
KDIGO 2024 + manufacturer label
- ONSET
- 45min · absorption
- PEAK
- 2h · Tmax
- t½
- 3.1d · metabolite t½
- DURATION
- 12h · per dose
EXCRETION
Renal — conjugates
route + CYP
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Avoid (cleft palate signal 1st trimester; floppy infant near term).
FDA category + note
Top interactionssee all 12 →
- MethylnaltrexoneSevereTextbookG&G 14e
- NalmefeneSevereTextbookG&G 14e
- NaloxoneSevereTextbookG&G 14e
- NaltrexoneSevereTextbookG&G 14e
Mechanism
Allosteric agonist at the GABA-A receptor benzodiazepine site, enhancing chloride conductance and producing anxiolysis, sedation, anticonvulsant and muscle-relaxant effects; long active metabolites (desmethylchlordiazepoxide, demoxepam, nordazepam).
Indications
Acute alcohol withdrawalAnxiety (short-term)Pre-operative sedation
Dosing
- Adult
- Alcohol withdrawal: 50–100 mg PO every 4–6 h on day 1, taper over 5–7 days. Anxiety: 5–25 mg PO 3–4 times daily; short-term.
- Pediatric
- Avoid <6 y; specialist use otherwise.
- Renal adjustment
- No fixed adjustment; caution.
- Hepatic adjustment
- Reduce dose; prolonged action (active metabolites).
- Geriatric
- Avoid (Beers criteria); if used, lower doses + shorter-acting agents preferred.
- Max dose
- 300 mg/day (alcohol withdrawal day 1, then taper)
Pharmacokinetics
Onset
30–60 min (oral)
Peak effect
~1–4 h (parent); active metabolites peak later
Duration
~12 h (per dose; effective t½ days due to metabolites)
Half-life
Parent 5–30 h; active metabolites ~50–100 h
Bioavailability
Well absorbed orally
Protein binding
~95%
Metabolism
Hepatic CYP3A4 (active metabolites)
Excretion
Renal (conjugates)
Contraindications
- Severe respiratory insufficiency / sleep apnoea
- Acute angle-closure glaucoma
- Myasthenia gravis
- Severe hepatic impairment
- Pregnancy
- Hypersensitivity
Side effects
Common
DrowsinessAtaxiaConfusion (elderly)HeadacheLethargy
Serious
- Dependence / withdrawal
- Falls / fractures (elderly)
- Respiratory depression with opioids/alcohol
- Paradoxical agitation
Pregnancy & lactation
Pregnancy
Avoid (cleft palate signal 1st trimester; floppy infant near term).
Lactation
Avoid breastfeeding (excretion + neonatal sedation).
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
Other Cns Depressants
Severe
Textbook
Typically fatal if combined in overdose.
Use with extreme caution; avoid if possible.
Source: G&G 14e
Alcohol
Severe
Database
Additive CNS depression
Avoid alcohol while taking
Source: Kimi deep-research + Cla
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
Related guidelines
Ask House about Chlordiazepoxide
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20