Acute toxicity profile of tolperisone in overdose: Observational poison centre-based study.

INTRODUCTION: Tolperisone is a centrally acting muscle relaxant that acts by blocking voltage-gated sodium and calcium channels. There is a lack of information on the clinical features of tolperisone poisoning in the literature. The aim of this study was to investigate the demographics, circumstances and clinical features of acute overdoses with tolperisone. METHODS: An observational study of acute overdoses of tolperisone, either alone or in combination with one non-steroidal anti-inflammatory drug in a dose range not expected to cause central nervous system effects, in adults and children (< 16 years), reported to our poison centre between 1995 and 2013. RESULTS: 75 cases were included: 51 females (68%) and 24 males (32%); 45 adults (60%) and 30 children (40%). Six adults (13%) and 17 children (57%) remained asymptomatic, and mild symptoms were seen in 25 adults (56%) and 10 children (33%). There were nine adults (20%) with moderate symptoms, and five adults (11%) and three children (10%) with severe symptoms. Signs and symptoms predominantly involved the central nervous system: somnolence, coma, seizures and agitation. Furthermore, some severe cardiovascular and respiratory signs and symptoms were reported. The minimal dose for seizures and severe symptoms in adults was 1500 mg. In 11 cases the latency between the ingestion and the onset of symptoms was known and was reported to be 0.5-1.5 h. CONCLUSIONS: The acute overdose of tolperisone may be life-threatening, with a rapid onset of severe neurological, respiratory and cardiovascular symptoms. With alternative muscle relaxants available, indications for tolperisone should be rigorously evaluated.

Fatal tolperisone poisoning: autopsy and toxicology findings in three suicide cases.

Tolperisone (Mydocalm) is a centrally acting muscle relaxant with few sedative side effects that is used for the treatment of chronic pain conditions. We describe three cases of suicidal tolperisone poisoning in three healthy young subjects in the years 2006, 2008 and 2009. In all cases, macroscopic and microscopic autopsy findings did not reveal the cause of death. Systematic toxicological analysis (STA) including immunological tests, screening for volatile substances and blood, urine and gastric content screening by GC-MS and HPLC-DAD demonstrated the presence of tolperisone in all cases. In addition to tolperisone, only the analgesics paracetamol (acetaminophen), ibuprofen and naproxen could be detected. The blood ethanol concentrations were all lower than 0.10 g/kg. Tolperisone was extracted by liquid-liquid extraction using n-chlorobutane as the extraction solvent. The quantification was performed by GC-NPD analysis of blood, urine and gastric content. Tolperisone concentrations of 7.0 mg/l, 14 mg/l and 19 mg/l were found in the blood of the deceased. In the absence of other autopsy findings, the deaths in these three cases were finally explained as a result of lethal tolperisone ingestion. To the best of our knowledge, these three cases are the first reported cases of suicidal tolperisone poisonings.

[Two complex suicidal poisonings with drugs and their medicolegal aspects]. / Dwa kompleksowe samobójcze zatrucia lekami w aspekcie orzecznictwa sadowo-lekarskiego.

The main subject of the study was a toxicological investigation of biological specimens coming from two cases of intoxication with mixture of drugs. Two young people decided to commit suicide by the use of mixture of drugs mainly analgesic in approximately equal doses. For one person the dose of drugs administered turned out to be fatal while second person survived with the symptoms of acute intoxication. The analysis carried out with the use of liquid chromatographic method with mass detection (HPLC/MS) confirmed the presence of mixture of drugs in blood of living person and in postmortem specimens of the victim in significant concentrations. The toxicological findings have delivered information for discussion in medico-legal and ethical aspects.

[Possible malignant hyperthermia as reaction to an overdose of myotonolytic, antidepressive and sedative drugs (author's transl)]. / Fragliche maligne Hyperthermiekrise bei Medikamentenintoxikation.

A 51-year-old male patient with no history of musculo-skeletal or myopathic abnormalities, but suffering from manic-depressive psychosis, attempted suicide with an overdose of dolpersin hydrochloride (Mydocalm), dipenzepine hydrochloride (Noveril), meprobamate (Mepronox) and nitrazepam (Mogadon). He developed high fever, muscle rigidity, tachycardia, arrhythmias, hypotension and mottled cyanosis, symptoms well-known in persons with malignant hyperthermia, an autosomally inherited disease of skeletal muscle. There is also discussed the manifestation and the symptoms of an acute rhabdomyolysis. The diagnosis was confirmed by chemical pathological laboratory findings, including respiratory and metabolic acidosis, myoglobinaemia accompanied by myoglobin diuresis, and elevated creatine phosphokinase (CPK values up to 2790 U/l). Electron microscopic examination of muscle tissue revealed signs of myolysis and mitochondrial reactions with pleoconic hyperplasia. No inhalation anaesthetics or skeletal muscle relaxants, such as succinyl choline, were used in this case. Therefore, malignant hyperthermia might have been induced by a combination of drugs which were not known to induce this abnormal muscular reaction. However, the muscle relaxant effect of dolpersin hydrochloride may have acted as a possible inducer of the attack.