Suicidal chloral hydrate poisoning

Two Cases of Chloral Hydrate Overdose

Chloral hydrate overdose is associated with cardiac toxicities, gastrointestinal tract injuries, central nervous system and respiratory depression. Among all the complications, cardiac arrhythmias are particularly concerning and frequently reported in the literature. The majorities of fatalities from chloral hydrate overdose are due to refractory cardiac arrhythmia. Chloral hydrate-induced arrhythmias are resistant to most of the standard anti-arrhythmic agents but have good response to propranolol. We report two cases of severe chloral hydrate overdose presenting with alarming cardiac rhythm disturbances. One of the patients was successfully treated with intravenous propranolol in the accident and emergency department. The management of chloral hydrate overdose in particular to its cardiac toxicity is reviewed.

Toxicology in the ICU: Part 2: specific toxins

This is the second of a three-part series that reviews the generalized care of poisoned patients in the ICU. This article focuses on specific agents grouped into categories, including analgesics, anticoagulants, cardiovascular drugs, dissociative agents, carbon monoxide, cyanide, methemoglobinemia, cholinergic agents, psychoactive medications, sedative-hypnotics, amphetamine-like drugs, toxic alcohols, and withdrawal states. The first article discussed the general approach to the toxicology patient, including laboratory testing; the third article will cover natural toxins.

Short-Term Chloral Hydrate Administration and Cancer in Humans

OBJECTIVE

Chloral hydrate, used as a hypnosedative in adults and children, has been shown to be genotoxic and carcinogenic in animal studies. We investigated the potential causal association between chloral hydrate exposure and cancer risk in humans.

METHODS

Cancer incidence was previously determined via biennial screening analyses of the 215 most commonly used drugs between 1976 and 1998 for a cohort of 143,574 outpatients at Kaiser Permanente who had prescriptions filled between 1969 and 1973. Among users of chloral hydrate, statistically significant elevations in standardised morbidity ratios were observed during various years for cancer at five anatomical sites, including the lung, stomach, prostate, skin melanoma and mouth floor. In this analysis, these associations were investigated using: (i) a dose-response analysis among exposed subjects; and (ii) a two-stage design with exposed and non-exposed persons.

RESULTS

There was evidence of an increasing risk of prostate cancer with increasing number of dispensings of chloral hydrate, which persisted after controlling for benign prostatic hypertrophy, vasectomy and obesity; however, the trend was not statistically significant. There was no evidence of a dose-response relationship between chloral hydrate and risk of any of the other four cancers. In the two-stage design, analyses comparing exposed and unexposed subjects showed no increased risk of cancer after controlling for confounding variables; however, the data were suggestive for prostate cancer, where the increased risk associated with chloral hydrate exposure after adjustment for confounding variables persisted. No dose-response relationship was seen for any of the other four cancer sites.

CONCLUSIONS

To our knowledge, this is the first study to examine the relationship between chloral hydrate exposure and cancer risk in humans. There was no persuasive evidence to support a causal relationship between chloral hydrate exposure in humans and the development of cancer. However, statistical power was low for weak associations, particularly for some of the individual cancer sites. Although animal data using much higher doses of chloral hydrate have demonstrated its genotoxicity and carcinogenicity, the effects of chloral hydrate in humans are still uncertain.

Dietary controlled carcinogenicity study of chloral hydrate in male B6C3F1 mice

Chloral hydrate, which is used as a sedative in pediatric medicine and is a by-product of water chlorination, is hepatocarcinogenic in B6C3F1 mice, a strain that can exhibit high rates of background liver tumor incidence, which are associated with increased body weight. In this study, dietary control was used to manipulate body growth in male B6C3F1 mice in a 2-year bioassay of chloral hydrate. Male B6C3F1 mice were treated with water or 25, 50, or 100 mg/kg chloral hydrate by gavage. The study compared ad libitum-fed mice with dietary controlled mice. The latter received variably restricted feed allocations to maintain their body weights on a predetermined "idealized" weight curve predictive of a terminal background liver tumor incidence of 15-20%. These mice exhibited less individual body weight variation than did their ad libitum-fed counterparts. This was associated with a decreased variation in liver to body weight ratios, which allowed the demonstration of a statistically significant dose response to chloral hydrate in the dietary controlled, but not the ad libitum-fed, test groups. Chloral hydrate increased terminally adjusted liver tumor incidence in both dietary controlled (23.4, 23.9, 29.7, and 38.6% for the four dose groups, respectively) and ad libitum-fed mice (33.4, 52.6, 50.6, and 46.2%), but a statistically significant dose response was observed only in the dietary controlled mice. This dose response positively correlated with markers of peroxisomal proliferation in the dietary controlled mice only. The study suggests that dietary control not only improves terminal survival and decreases interassay variation, but also can increase assay sensitivity by decreasing intra-assay variation.

Successful treatment of chloral hydrate cardiac toxicity with propranolol

A case of chloral hydrate overdose causing resistant ventricular arrhythmias is presented. Our case and other case reports suggest that chloral hydrate-induced arrhythmias are resistant to standard antiarrhythmic agents and that intravenous beta blockers should be the firstline treatment for these arrhythmias.