Dantrolene toxicity

Ricaurte GA, McCann UD, Szabo Z, et al Toxicodynamics and long-term toxicity of the recreational drug 3,4-methylenedioxy-methamphetamine (MDMA, Ecstasy ). Toxicol Lett 112-113 143-146, 2000 Robinson TN, Killen JD, Taylor CB, et al Perspectives on adolescent substance use a defined population study. JAMA 258 2072-2076, 1987 Rubinstein JS Abuse of antiparkinson drugs feigning of extrapyramidal symptoms to obtain trihexyphenidyl. JAMA 239 2365, 1978 Rumack BH (ed) LSD, in Poisindex, Vol 54. Denver, CO, Micromedex, 1987 Rusyniak DE, Banks ML, Mills EM, et al Dantrolene use in 3,4-methylenedioxymethamphetamine ( ecstasy )-medicated hyperthermia (letter). Anesthesiology 10 263, 2004... 

There is a very great demand for drugs for the relief of anxiety. This was formerly met by the use of alcohol, bromides or barbiturates, which carried the risk of abuse or dangerous toxicity. The first of the modern minor tranquilizers, introduced from 1946 onwards, were drugs described as skeletal muscle relaxants. These were mainly derivatives of polyhydric alcohols, but heterocyclic examples included metaxolone (161), which is related to the aryl ethers of glycerol, chlorzoxazone (162) and chlormezanone (163). Dantrolene sodium (164) is a muscle relaxant and CNS depressant. 

Since the toxic effects of MDMA resemble certain features of both the serotonin syndrome and the neuroleptic malignant syndrome, some have suggested that MDMA may have combined actions on both the dopamine and serotonin systems (37). However, dantrolene (which may be helpful in cases of neuroleptic malignant syndrome) does not appear to be useful in dealing with MDMA toxicity (38). 

The absorption of oral dantrolene can be significantly increased by metoclopramide (15). As the risk of hepatotoxicity has been related to the dosage of dantrolene, increased clinical surveillance is necessary to avoid toxicity of dantrolene during concurrent treatment with metoclopramide. 

Toxicity The sedation produced by diazepam is significant but milder than that produced by other sedative-hypnotic drugs at doses that induce equivalent muscle relaxation. Baclofen produces less sedation than diazepam. Dantrolene causes significant muscle weakness but less sedation than either diazepam or baclofen. Tizanidine may cause drowsiness and hypotension. 

Carbamazepine toxicity has been reported in a patient given oxybutynin and dantrolene. 

Vander T, Odi H, Bluvstein, Ronen J, Catz A. Carbamazepine toxicity following cc bulynin and dantrolene adm inistration a case report. Spinal Cord (2005) 43,252-5. 

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