Fatal Tolperisone Poisoning: Autopsy and Toxicology findings in Three Suicide Cases
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Forensic Science International 215 (2012) 101–104 Contents lists available at ScienceDirect Forensic Science International jou rnal homepage: www.elsevier.com/locate/forsciint Fatal tolperisone poisoning: Autopsy and toxicology findings in three suicide cases a, b,1 a,2 a,3 Frank Sporkert *, Christophe Brunel , Marc P. Augsburger , Patrice Mangin a University Centre of Legal Medicine Lausanne-Geneva, Rue du Bugnon 21, CH-1011 Lausanne, Switzerland b University Centre of Legal Medicine Lausanne-Geneva, Rue Michel-Servet 1 – CH-1211 Geneva 4, Switzerland A R T I C L E I N F O A B S T R A C T 1 Article history: Tolperisone (Mydocalm ) is a centrally acting muscle relaxant with few sedative side effects that is used Received 30 September 2010 for the treatment of chronic pain conditions. We describe three cases of suicidal tolperisone poisoning in Received in revised form 19 May 2011 three healthy young subjects in the years 2006, 2008 and 2009. In all cases, macroscopic and microscopic Accepted 20 May 2011 autopsy findings did not reveal the cause of death. Available online 17 June 2011 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 Keywords: the presence of tolperisone in all cases. In addition to tolperisone, only the analgesics paracetamol Tolperisone (acetaminophen), ibuprofen and naproxen could be detected. The blood ethanol concentrations were all Muscle relaxant lower than 0.10 g/kg. Tolperisone was extracted by liquid–liquid extraction using n-chlorobutane as the Fatal poisoning Suicide extraction solvent. The quantification was performed by GC–NPD analysis of blood, urine and gastric Lethal intoxication 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. ß 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction polysynaptic reflex activity [4,5]. Because it has fewer sedative side effects than other muscle relaxants, psychomotoric Tolperisone, 2-methyl-1-(4-methylphenyl)-3-(piperidinyl)-1- impairment (driving, operation of machines) is strongly propanone (chemical structure in Fig. 1), was first described as a reduced. Possibly critical side effects of tolperisone were centrally acting muscle relaxant by Porszasz et al. in 1961 [1]. In reported by Ribi et al. in four patients at the University Hospital contrast to peripheral muscle relaxants and neuromuscular- of Geneva between November 2001 and March 2003; these side blocking drugs such as curare derivatives, centrally acting muscle effects included vasodilatation, hypotension and anaphylactic relaxants, also referred to as spasmolytics, such as carisoprodol, reactions [6]. baclofen, clonidine, diazepam, tetrazepam and gabapentin, act at the A typical treatment regimen for tolperisone is 3 Â 50 mg per level of the cortex, brain stem or spinal cord. Tolperisone, eperisone, day (max. 600 mg), ingested orally. The oral bioavailability is low, inaperisone, lanperisone and silperisone are the best known drugs approximately 20%. The maximum plasma concentrations, 64– within the group of the piperidine derivatives [2]. Tolperisone is 785 ng/ml (average 297 ng/ml), were measured after oral admin- generally used as a racemic mixture. After injection of the active istration of 450 mg tolperisone [7]. Tolperisone is mainly stereoisomer, tolperisone is rapidly converted into the racemate [3]. metabolized by CYP2D6. The main metabolites are hydroxy- + Tolperisone inhibits voltage-dependant Na -channels in the methyl-tolperisone (by hydroxylation) and hydroxy-tolperisone brain-stem and, as a result, inhibits pathologic mono- and (by reduction). The elimination half-life varies from 43 min to 174 min depending on the application [7,8]. The biphasic elimination after administration of a single dose is completed * Corresponding author. Tel.: +41 21 314 56 26, fax: +41 21 314 73 29. after 24 h. E-mail addresses: [email protected] (F. Sporkert), To the best of our knowledge, no data about toxic and lethal [email protected] (C. Brunel), [email protected] tolperisone concentrations have been published in the scientific (M.P. Augsburger), [email protected] (P. Mangin). 1 literature. Only one case of suicidal ingestion of a mixture of ten Tel.: +41 22 379 56 19. 2 drugs including tolperisone, yielding a tolperisone blood concen- Tel.: +41 21 314 70 85. 3 Tel.: +41 21 314 70 64. tration of 3.36 mg/kg, was found in the literature [9]. 0379-0738/$ – see front matter ß 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2011.05.025 102 F. Sporkert et al. / Forensic Science International 215 (2012) 101–104 TIC: T05 .D\data.ms 9.89 6 1.4e +07 1.2e +07 7.91 9 1e+07 7.84 5 Tolperisone 8000000 12.92 3 6000000 18.99 4 Abundance 15.63 8 19.51 6 4000000 8.824 13.38 7 13.821 16.794 19.58 2 5.199 14.82 5 16.482 17.1217.40 72 2000000 11.1811.822 9 14.039 25.91 6 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 Time--> 98.2 Scan 1749 (12.929 min): T05.D\data.ms 2800000 91 CH3 2400000 98 O 2000000 119 N * 1600000 CH3 Abundance 1200000 800000 400000 91.1 (M-CH )+ M+ 55.2 119.1 3 77.1 138.1 161.2 184.1202.2 230.2 245.3 0 60 80 100120140160180200220240260280 m/z--> Fig. 1. Total ion chromatogram (TIC) and MS spectra of tolperisone in the blood extract of case 2 and corresponding library spectra (MPW2007). 40, 60 and 48 h, respectively, after the death. Post-mortem serum was obtained by 2. Case histories direct centrifugation of peripheral femoral blood during autopsy. Blood, urine and gastric contents were submitted to a systematic toxicological Case 1: A 14-year-old female was found dead at home by her analysis according to our routine procedure [10]. relatives in 2006. No sign of struggle was observed at the place of death. According to the police investigation, the girl had attempted 3.2. Reagents suicide using drugs four months earlier. Tolperisone hydrochloride, paracetamol, naproxen sodium, ibuprofen sodium, Case 2: A 20-year-old female was found dead in her boyfriend’s and 5-(p-methylphenyl)-5-phenylhydantoin (MPPH) were obtained from Sigma– home in 2008. A suicide note and several drugs, among them Aldrich (Buchs, Switzerland). The internal standard (I.S.) methaqualone was tolperisone, were discovered at the place of death. obtained from Lipomed (Arlesheim, Switzerland). Sodium chloride (p.a.), potassium Case 3: A 41-year-old female was found dead in the summer of dihydrogen phosphate (p.a.), ammonium chloride (p.a.), ammonium hydroxide (25%), acetonitrile (HPLC grade), ethyl acetate (GC grade), methanol (GC grade), n- 2009 in a forest. Three years before, she had obtained a 1 chlorobutane (GC grade), and toluene (GC grade) were purchased from Sigma– Mydocalm prescription because of psychosomatic pain. No sign Aldrich (Buchs, Switzerland). of crime or drug ingestion was noted at the place of death. The external examinations of the bodies were unremarkable, 3.3. Solutions and the macro- and microscopic autopsy findings all showed Stock solutions were prepared at 1 mg/ml in methanol for tolperisone and visceral congestion and lung edema. The autopsy findings did not methaqualone and at 10 mg/ml for paracetamol, ibuprofen, naproxen and MPPH. reveal the cause of death in any of the three cases. Working solutions of tolperisone and the I.S. were at 10 mg/ml in methanol. For quality controls, second working and stock solutions of tolperisone with the same concentrations as above were prepared. 3. Material and methods 3.1. Samples 3.4. Extraction procedures Biological fluids and tissue samples of the three autopsy cases were routinely Blood, post-mortem serum, urine, cerebrospinal fluid, bile and gastric contents taken during autopsy at the University Center of Legal Medicine of Lausanne and were extracted according to the following procedures: to 0.5 ml of each liquid were immediately frozen and kept until analysis at À21 8C. The autopsies took place sample (for bile and gastric content, 0.01 ml of the homogenized sample), 100 ml of F. Sporkert et al. / Forensic Science International 215 (2012) 101–104 103 the I.S. solution at 10 mg/l (final concentration, 1000 mg/l) and 2 ml of saturated Additionally, external calibration was performed from 0.1 to 10 mg/l at seven ammonium chloride buffer (pH 9.5) were added. n-Chlorobutane (4 ml) was used as different concentrations (0.1, 0.2, 0.4, 1.0, 2.0, 5.0 and 10 mg/l) in drug-free whole the extraction solvent because of its good efficiency in an extraction test [11]. After bovine blood (EDTA stabilized). Six tolperisone free blood extracts were injected on a 15 min extraction on a horizontal shaker at 200 strokes/min, the samples were the GC–NPD in order to test the system’s selectivity. centrifuged for 5 min at 4000 rpm. The upper layer was collected and evaporated to Because no commercial quality control sample was available, an internal quality dryness at 30 8C under a gentle stream of nitrogen. The residue was dissolved in control sample based on an independent stock solution of 1.0 mg/l was prepared 100 ml of toluene. Liver and brain tissues (each 0.5 g, to which was added 1 ml of and analyzed in the same way.