Chloral Hydrate Stats & Data
RNFNDJAIBTYOQL-UHFFFAOYSA-NPharmacology
DrugBankDescription
A hypnotic and sedative used in the treatment of insomnia. The safety margin is too narrow for chloral hydrate to be used as a general anesthetic in humans, but it is commonly used for that purpose in animal experiments. It is no longer considered useful as an anti-anxiety medication.
Metabolism
Metabolized by the liver and erythrocytes to form trichloroethanol, an active metabolite. This reaction is catalyzed by alcohol dehydrogenase and other enzymes. Oxidation of chloral hydrate and trichloroethanol to trichloroacetic acid in the liver and kidneys also occurs to a lesser extent. Trichloroethanol also undergoes glucuronidation to produce an inactive metabolism.
Absorption
Rapidly absorbed in the GI tract following oral or rectal administration. Chloral hydrate and its active metabolite, trichloroethanol, have been detected in CSF, umbilical cord blood, fetal blood, and amniotic fluid.
Indication
Mainly used as a hypnotic in the treatment of insomnia; however, it is only effective as a hypnotic for short-term use. May be used as a routine sedative preoperatively to decrease anxiety and cause sedation and/or sleep with respiration depression or cough reflex.
Elimination
Trichloroethanol, trichloroethanol glucuronide, and trichloroacetic acid are excreted in the urine. Some trichloroethanol glucuronide may be secreted into bile and excreted in the feces.
Receptor Profile
Receptor Actions
Toxicity
PubChemChloral hydrate is used in human and veterinary medicine as a sedative and hypnotic drug. HUMAN EXPOSURE: The major route of exposure of the general public is from drinking water, as chloral hydrate is formed when drinking water is disinfected with chlorine.
Carcinogenicity
Group 2A: Probably carcinogenic to humans
Tolerance & Pharmacokinetics
drugs.wikiNo tolerance chart. Our decay curves for these drugs were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.
How fast tolerance to these drugs fades after a break has not been measured well enough to draw, so don't count on a dose you used to take still being safe: after time off, start with a much smaller amount and don't use alone. Mixing sedatives with each other, with alcohol or with opioids sharply raises the risk of a fatal overdose. If you've been using regularly, don't stop suddenly: withdrawal from benzodiazepines, alcohol or GHB/GBL can cause seizures or delirium, so get medical help to cut down gradually.
Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder
Experience Report Analysis
ErowidDemographics
Gender Distribution
Too few reports for a chart: gender is known from 10 reports, and a split is drawn only from 20 reports or more. Counts are shown instead. Why 20?
- Male 8 of 10
- Female 2 of 10
Age Distribution
Reports Over Time
Effect Analysis
ErowidEffects aggregated from 7 experience reports (7 single-substance Erowid)
Effect Sentiment Distribution
Confidence Distribution
Each bar is the share of reports mentioning the effect; its whisker, and the band on the rows below, is the 95% interval: where the share could plausibly be with other reports of the same kind.
Too few reports for bars: these effects come from 7 single-substance Erowid reports, and a bar is drawn only from 20 reports or more. With fewer, a percentage cannot tell a common effect from a rare one. Counts are shown instead. Why 20?
Positive Effects 2
Adverse Effects 0
Also reported in combinations. In the 3 Chloral Hydrate reports where another drug was taken too, 1 mentions hospital, emergency services or an overdose, 0 a seizure and 0 psychosis (too few reports for percentages). In the 7 single-substance reports: 2, 1 and 0. These are not in the figures above: they cannot be put down to Chloral Hydrate alone, and a mention is not always something that happened to the writer.
Real-World Dose Distribution
ErowidFrom 10 of 10 recorded dose entries: those that state a weight (mg, g or µg), in routes with at least five of them. Values above Q3 + 3×IQR, far above what people typically take, are left out; they can include real heavy doses and overdoses, not only mistakes.
Oral (n=9)
Form / Preparation
Most common forms and preparations, as a share of the 8 reports that give one
Too few reports for bars: these forms come from 8 reports, and a bar is drawn only from 20 reports or more. With fewer, a percentage cannot tell a common effect from a rare one. Counts are shown instead. Why 20?
- Liquid 5 of 8
Harm Reduction
drugs.wikiLethal dose margin is narrow: deaths have occurred with ingestions as low as ~4–10 g; overdose presents with profound CNS depression, respiratory suppression, and risk of cardiac arrhythmias. Co-ingestion with alcohol or other depressants (opioids, benzodiazepines, GHB/GBL) markedly increases risk of loss of consciousness, respiratory depression, aspiration, and death—avoid these combinations entirely and place any unresponsive person in the recovery position while seeking emergency care. Chloral hydrate is metabolized primarily by alcohol dehydrogenase to trichloroethanol (active) and further to trichloroacetic acid; genetic variation and concurrent alcohol use can meaningfully alter both potency and duration between individuals. In cirrhosis or hepatic decompensation, chloral hydrate can precipitate or worsen hepatic encephalopathy; avoid use in significant liver disease and in untreated sleep apnea. Cardiac irritability/arrhythmia can occur in overdose and in susceptible individuals; those with structural heart disease or on other QT-/rhythm‑affecting drugs should avoid nonmedical use. Residual psychomotor impairment may persist into the next day due to metabolite half-lives; do not drive or operate machinery for at least a full night after dosing. Repeated frequent use rapidly builds tolerance and can cause dependence; withdrawal may begin within 12–24 hours after cessation in heavy users and may resemble alcohol/barbiturate withdrawal (including delirium)—medical supervision is strongly advised for dependent users. Oral and rectal routes can irritate mucosa; always dilute liquids and avoid concentrated solutions to reduce GI irritation; injection is strongly discouraged due to vein and tissue irritation. Products and syrups may vary in concentration; use an accurate milligram scale or clearly labeled pharmaceutical preparations to avoid dosing errors. Breast milk transfer occurs and may sedate infants; avoid during pregnancy and lactation unless medically supervised. If severe vomiting, chest pain, palpitations, confusion, or shallow breathing occur after use, seek emergency help immediately and avoid giving more depressants while awaiting care.
References
Data Sources
Cited References
Additional references
- Erowid Chloral Hydrate Basics
- Erowid Chloral Hydrate Vault
- LiverTox: Chloral hydrate
- IARC/WHO: Chloral & Chloral Hydrate Monograph
- WHO Indoor Air: Trichloroethylene (metabolite kinetics excerpt)
- DrugBank: Chloral Hydrate (DB01563)
- Drugs-Forum Wiki: Chloral Hydrate (dosing/ROA notes)
- TripSit drug combinations (CNS depressant combo risks)