Chloral Hydrate

Allopathic
Indications
  • Short-term Sedation and Hypnosis:
    Used primarily for short-term treatment of insomnia, especially when difficulty in falling asleep is prominent.
  • Preoperative Sedation:
    Employed as a sedative before anesthesia or minor surgical procedures.
  • Sedation in Pediatric Patients:
    Occasionally used for sedation prior to diagnostic procedures or dental work.
  • Off-label Uses:
    Sometimes used for managing agitation or delirium in select cases under close supervision.
Dosage & Administration

Adults:

  • Oral dose for insomnia: 500 mg to 1 g at bedtime.
  • Maximum dose usually not exceeding 2 g per day.
  • Sedation dose before procedures: 1 g orally 30 minutes prior.

Pediatrics:

  • Dose usually 25 to 50 mg/kg orally, max 1 g, given 30 to 60 minutes before procedure.

Elderly:

  • Start at lower doses due to increased sensitivity and risk of adverse effects.

Special Populations:

  • Renal or hepatic impairment: Use caution; no precise dosage adjustments established.
  • Administer orally, preferably with water or juice.

Duration:

  • Short-term use only; generally limited to 1–2 weeks.
Mechanism of Action (MOA)

Chloral hydrate is a sedative-hypnotic that is metabolized in the liver to trichloroethanol, its active metabolite, which acts on the central nervous system to produce sedation. It enhances the activity of gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter, by modulating GABA_A receptor function, leading to increased neuronal inhibition and CNS depression. This results in sedation, hypnosis, and anxiolysis.

Pharmacokinetics
  • Absorption:
    Rapidly absorbed from the gastrointestinal tract.
  • Distribution:
    Widely distributed throughout body tissues, crosses the blood-brain barrier.
  • Metabolism:
    Extensively metabolized in the liver to active metabolite trichloroethanol and trichloroacetic acid.
  • Elimination:
    Metabolites are excreted mainly via the kidneys.
  • Half-life:
    Parent compound short (~8 hours); active metabolite trichloroethanol has a half-life of approximately 8 to 12 hours.
Pregnancy Category & Lactation
  • Pregnancy:
    FDA Category C — Animal studies have shown adverse effects; no adequate human studies. Use only if potential benefit justifies risk.
  • Lactation:
    Excreted in breast milk; potential CNS depression in infants. Use caution or avoid during breastfeeding.
Therapeutic Class
  • Sedative-hypnotic
  • Non-benzodiazepine sedative
Contraindications
  • Known hypersensitivity to chloral hydrate or its metabolites.
  • Severe hepatic or renal impairment.
  • Porphyria.
  • Severe respiratory depression.
  • Acute intoxication with alcohol, barbiturates, or other CNS depressants.
Warnings & Precautions
  • Risk of respiratory depression, especially when combined with other CNS depressants.
  • Potential for dependence and tolerance with prolonged use.
  • Use with caution in elderly due to increased sensitivity and fall risk.
  • Monitor for paradoxical excitation or behavioral changes.
  • Avoid abrupt discontinuation after prolonged use to prevent withdrawal symptoms.
Side Effects

Common:

  • Drowsiness
  • Dizziness
  • Headache
  • Gastrointestinal upset (nausea, vomiting)

Serious/Rare:

  • Respiratory depression
  • Hypotension
  • Confusion or agitation
  • Allergic reactions including rash and angioedema
  • Dependence and withdrawal symptoms with long-term use
Drug Interactions
  • Additive CNS depression with alcohol, benzodiazepines, barbiturates, opioids, and other sedatives.
  • May potentiate effects of other CNS depressants leading to respiratory depression.
  • Enzyme inducers or inhibitors affecting liver metabolism may alter levels.
Recent Updates or Guidelines
  • Usage has declined due to safety concerns and availability of safer alternatives.
  • Guidelines recommend limiting use to short-term treatment (less than 2 weeks).
  • Emphasis on caution in elderly and patients with comorbidities.
  • Avoid routine use in pediatric sedation due to variable response and safety concerns.
Storage Conditions
  • Store at 20°C to 25°C (68°F to 77°F).
  • Protect from light and moisture.
  • Keep container tightly closed.
  • Keep out of reach of children.