Journal of Analytical Toxicology 2015;39:41 –44 doi:10.1093/jat/bku121 Advance Access publication October 22, 2014
Article
Postmortem Femoral Blood Reference Concentrations of Aripiprazole, Chlorprothixene, and Quetiapine Louise Skov*, Sys Stybe Johansen and Kristian Linnet Section of Forensic Chemistry, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V’s Vej 11, DK-2100 Copenhagen Ø, Denmark *Author to whom correspondence should be addressed. Email: [email protected]
Postmortem femoral blood concentrations of the antipsychotic drugs aripiprazole, chlorprothixene and its metabolite, and quetiapine were determined by LC–MS-MS in 25 cases for aripiprazole and 60 cases each for chlorprothixene and quetiapine. For cases where the cause of death was not related to the considered drugs, the following blood concentration intervals (10 –90 percentiles) were observed: 0.049 – 0.69 mg/kg for aripiprazole, 0.006 – 0.24 mg/kg for chlorprothixene, and 0.006 – 0.37 mg/kg for quetiapine. These concentration ranges largely correspond to therapeutic plasma levels observed in vivo suggesting no or only limited postmortem redistribution for aripiprazole, chlorprothixene with metabolite, and quetiapine in these cases. One fatality caused by chlorprothixene with a blood level of 0.90 mg/kg was recorded, and in six cases chlorprothixene was judged to be contributing to death with concentrations 0.43– 0.91 mg/kg. No fatalities exclusively ascribed to the two other drugs were observed, but aripiprazole was considered to be contributing to death in one case (1.9 mg/kg) and quetiapine in seven cases with concentrations 0.35 – 10.0 mg/kg. The presented values may serve as a reference for judgment of postmortem cases with presence of these antipsychotics.
Introduction In postmortem cases, blood levels of drugs may not equal in vivo concentrations in plasma because of postmortem redistribution and differences between plasma and whole blood concentrations (1 –4). Thus, it has been recommended to estimate reference levels from postmortem cases since postmortem reference concentrations are a valuable asset for determining cause of death (5, 6). Druid and Holmgren and later Reis et al. compiled postmortem drug levels and divided them into three categories: A: concentrations in cases ascribed to fatal intoxication with the drug as the sole cause of death, B: concentrations where the drug is considered a contributing cause of death, and C: concentrations observed when the drug is not considered to be directly related to the cause of death, e.g., suicide by hanging or shooting (5, 6). This categorization is primarily based on circumstances and not on drug concentrations. Postmortem reference values have also been reported in other studies, e.g., amlodipine (7), risperidone (8), olanzapine (9), and more recently for 16 different sedative and hypnotic drugs (10). In other studies, postmortem concentrations were reported for 25 and 129 drugs, respectively, including several antipsychotics, but there were no categorization in A –C case types (11, 12). Here, we present concentration ranges in postmortem blood for aripiprazole, chlorprothixene, and quetiapine. The results were categorized A – C and compared with previously published findings. The three drugs investigated here are all antipsychotic drugs used primarily in the treatment
of schizophrenia and bipolar disorder. The recommended daily doses for aripiprazole are 10 –30 mg orally, for chlorprothixene 20– 600 mg in two divided portions either by oral or intramuscular routes, and for quetiapine 150 –800 mg in two or three divided oral portions (13). During therapy, the average plasma/serum levels for aripiprazole have been measured up to 0.96 mg/L (14), for chlorprothixene up to 0.3 mg/L (15, 16), and for quetiapine up to 1.1 mg/L (17) as listed in Table I. Concerning aripiprazole, adults or children who ingested acute overdoses have suffered from mild sedation (40) to coma (22), but so far no deaths have been recorded, even in cases where the concentration were elevated by up to 3- to 4-fold over normal therapeutic levels suggesting that aripiprazole has a wide therapeutic index. The side effects of chlorprothixene can be so substantial that normally a full effective dose cannot be given, so chlorprothixene is often given in combination with other more potent antipsychotic drugs to allow remission of the psychotic disorder. Overdose symptoms can be confusion, hypotension, and tachycardia (13) and several fatalities have been reported with concentrations in postmortem blood ranging from 0.1 to 7.0 mg/L (5, 23 – 25). Overdose symptoms for quetiapine poisoning can include drowsiness, disorientation (41), neuroleptic malignant syndrome (42), EKG abnormalities (30), together with tachycardia, and coma (31). Several fatalities have been reported with postmortem blood concentrations ranging from 0.28 to 170 mg/L (35 –39).
Experimental Postmortem samples Screening for aripiprazole, quetiapine, chlorprothixene, and its active N-desmethylmetabolite is part of the routine toxicological investigations of forensic cases. Aripiprazole was detected in 25 cases in the period 2006 – 2013, chlorprothixene in 60 cases, and quetiapine in 60 cases for the period 2009 – 2012. Dosing details were not available. Autopsies were performed within 1 – 4 days after the bodies arrived at the Department of Forensic Medicine; storage was at 58C. Blood was drawn from the femoral vein at the beginning of the autopsy after the body was opened without ligation of the iliac vein. The blood samples were preserved with 1% sodium fluoride and stored at 2208C until analysis.
Analytical method Aripiprazole cases from 2006 to 2011 (N ¼ 16) and all chlorprothixene with metabolite (N ¼ 60), and quetiapine (N ¼ 60) cases were quantified by a previously published method (43) involving liquid – liquid extraction, separation by ultra-high-performance liquid chromatography and detection by tandem mass
# The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected]
Table I. In Vivo and Postmortem Concentrations of Aripiprazole, Chlorprothixene, N-Desmethylchlorprothixene, and Quetiapine Reported in the Literature (mg/L or mg/kg)
Table II. Postmortem Blood Concentrations of Aripiprazole, Chlorprothixene, N-Desmethylchlorprothixene, and Quetiapine for Categories A, B, and C in Present Study (mg/kg)
Matrix
Categorya
Aripiprazole Serum Serum Serum Serum Plasma Serum Chlorprothixen Plasma Plasma/serum Postmortem blood Postmortem blood Postmortem blood Postmortem blood N-Desmethylchlorprothixene Postmortem blood Postmortem blood Quetiapine Plasma Serum Plasma Plasma Serum Plasma Serum Serum Serum Serum Postmortem heart blood Postmortem femoral blood Postmortem heart blood Postmortem heart blood Postmortem cavity blood Postmortem femoral blood
Therapeutic level
Clinical intoxication Fatalities cases/B postmortem cases
0.23 –0.96 [118] 0.11 –0.55 [27] 0 –0.87 [164] 0.04 –0.65 [33] 0.10 –0.45 [48]
(14) (18) (19) (20) (21) (22)
1.4 [1] 0.02 –0.30* 0.04 –0.30* 0.2 [1]
0.4 –0.8* 0.60 –7.0 [2] 0.60 –2.0[2]
0 –1.1 [12] 0 –0.86 [53] 0.02 –0.88 [21] 0.59 –0.92 [36] 0.14 –0.37 [11] 1.8 [1] 12.7 [1] 1.8 [1] 1.1 –8.8 [14] 8.7 [1] 0.43 –49 [5] 1.3 –30 [8]
Ref.
1.6 –1.7 [2] 0.4 [1] 0.1 [1] 0.13– 0.25 [2]
(16) (15) (5) (23) (24) (25)
0.3 [1] 0.06– 0.26 [2]
(23) (25)
(17) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) 2.6 –14 [2] (36) 7.2 –16 [3] (37) 0.72– 18.4 [12] (38) 170 [1] (39) 0.28– 19.3 [12] (38)
Number of observations, N, are indicated by [ ]. N not available indicated by asterisk.
spectrometry. Aripiprazole was not originally included in the method but added later. Reference material of aripiprazole was obtained from Bristol-Myers Squibb Company (Syracuse, New York, USA). All blood samples are initially weighed; hence, the results are given in mg/kg. The detection was performed by positive electrospray ionization operating in multiple reaction monitoring (MRM) mode with two MRM transitions of each drug. The published method was validated for 25 common pharmaceuticals including chlorprothixene with metabolite and quetiapine (43). A supplementary validation for aripiprazole showed a linear range from 0.002 to 1.0 mg/kg (LOQ 0.002 mg/kg) and a process efficiency of 60%. The intermediary precisions were 20 and 17% with bias against the spiked level of ,2% for the low and high controls at 0.020 and 0.30 mg/kg. Aripiprazole samples from 2012 (N ¼ 9) were measured by another method, which is under preparation for publication. The sample preparation was based on solid-phase extraction (SPE) that was described in detail in (44), while the UHPLC –MS-MS conditions are as described in (43) with the following transitions for aripiprazole: 448!285 and 448!176 with a cone voltage of 49 V and collision energy at 25 and 31 eV, respectively. The new method had a linear range from 0.002 to 2.5 mg/kg (LOQ 0.002 mg/kg) and a process efficiency of 38%, while the intermediary precision was 13 and 14% with bias of 6 and 16% for the low and high controls at 0.020 and 0.30 mg/kg, respectively. The metabolite 42 Skov et al.
N
Aripiprazole A – B 1 C 20 Chlorprothixene A 1 B 6 C 51 N-Desmethylchlorprothixene A 1 B 6 C 51 Chlorprothixene/metabolite ratio A 1 B 6 C 51 Quetiapine A – B 7 C 51
Range
Median
10– 90 percentile
– 1.9 0.015 –0.91
– 1.9 0.20
– – 0.049 –0.69
0.90 0.43 –0.91 0.002 –0.43
0.90 0.52 0.042
– – 0.006 –0.24
0.51 0.23 –0.93 0.002 –0.20
0.51 0.24 0.033
– – 0.006 –0.086
1.76 0.87 –2.21 0.50 –8.00
1.76 1.87 1.53
– – 0.64 –4.21
– 0.35 –10.0 0.003 –0.80
– 1.30 0.13
– – 0.006 –0.37
a A: drug is considered the sole cause of death; B: drug is considered a contributing cause of death; C: drug is not considered to be directly related to the cause of death.
dehydroaripiprazole was not quantified, but separation between the parent compound and metabolite was achieved with the chromatographic system, so no interference occurred for the aripiprazole determinations.
Results and discussion The concentration data are given in Table II for all the drugs studied separated into A –C categories.
Aripiprazole For the 25 aripiprazole cases, there was a single category B case, 20 category C cases, and 4 cases with uncertain cause of death (U). The concentration of the single aripiprazole category B case, 1.9 mg/kg, is of the same order of magnitude as observed in a clinical intoxication case (22). Besides aripiprazole poisoning, the deceased had a toxic/fatal methadone level of 1.4 mg/kg. For the 20 C cases, the cause of death was poisoning with other drugs (13), suffocation (1), stabbing (1), and natural causes for the remaining 5. The concentration levels of the category C cases (N ¼ 20), which ranged from 0.015 to 0.91 mg/kg, were in the same order of magnitude as reported in vivo therapeutic plasma or serum levels from below LOQ to 0.96 mg/L (14, 18 – 21). The 10 – 90 percentile for aripiprazole was determined to 0.049 –0.69 mg/kg.
Chlorprothixene There were 1 A case, 6 B cases in addition to 51 C cases. The latter included 33 cases of poisoning with other psychoactive drugs and/or ethanol, 3 drowning and suffocation cases, and 15 cases with a natural cause of death. For two cases, the cause of death was uncertain (U). The concentration of the A case, 0.90 mg/kg, was of the same order of magnitude as values given in the literature for fatalities
with chlorprothixene present as the only drug (5, 23 – 25). For the six category, B cases the concentration range 0.43 – 0.91 mg/kg was about the same as the plasma/serum range reported for clinical intoxication cases 0.4 – 0.8 mg/L (15) and the range for blood in postmortem cases 0.60 – 7.0 mg/kg (5, 23). All B cases involved multiple drugs, and four of the six cases involved benzodiazepines in therapeutic levels, one case involved opioids in therapeutic levels, five cases involved antidepressants up to toxic levels, two cases involved other antipsychotic drugs at therapeutic to toxic levels, and one case included the antihistamine hydroxyzine at a toxic level. The concentrations of the category C cases (N ¼ 51), which ranged from 0.002 to 0.43 mg/kg, were of the same order of magnitude as stated in vivo therapeutic plasma/serum levels 0.02 – 0.3 mg/L (15, 16). The 10 – 90 percentile was determined to 0.006 –0.24 mg/kg. The A category case had a drug/metabolite ratio of 1.76, and the medians for the B and C categories were 1.87 and 1.53, respectively. In the literature, three chlorprothixene postmortem overdose cases have been reported with an average drug/metabolite ratio of 1.31 (23, 25).
This is in opposition to the majority of antipsychotic drugs that tend to exhibit increases of postmortem values. Even though postmortem redistribution generally is more pronounced in heart than in femoral blood, postmortem redistribution has previously been reported in femoral blood as well (46, 47). On the other hand, quetiapine has recently been reported not to undergo postmortem redistribution (48).
Quetiapine For the 60 quetiapine cases, there were no cases where quetiapine poisoning was classified as the sole cause of death, but seven cases were considered category B cases, where quetiapine was a contributing factor to death. The cause of death for all the B cases was determined as multiple drug poisoning. In five cases, opioids were present in therapeutic to possible lethal levels, five cases involved multiple antipsychotic drugs up to toxic levels, four cases had benzodiazepines levels from therapeutic to toxic levels, and four cases had antidepressants from therapeutic to elevated levels. Fifty-one cases were considered C cases with cause of death unrelated to quetiapine. These cases included 32 cases of poisoning with other psychoactive drugs and/or ethanol, 11 cases of natural death, 3 cases of suffocation, 2 cases of drowning, 2 cases of hanging, and a single case of carbon monoxide poisoning. The cause of death for the two cases left was classified as uncertain. The seven category B cases had concentrations 0.35 – 10.0 mg/kg, which were below or in the range of serum/plasma values for clinical intoxication cases, 1.1 –12.7 mg/L (30 –34). The concentrations of the category C cases (N ¼ 51), which ranged from 0.003 to 0.80 mg/kg, were in the same range as reported in vivo therapeutic values, from below LOQ to 0.92 mg/L (17, 26 – 29). The 10 – 90 percentile was determined to 0.006 – 0.37 mg/kg.
References
Postmortem redistribution Antipsychotic drugs usually have high volumes of distribution with high tissue concentrations, which are considered to predispose to postmortem redistribution (45). However, concentrations of the three antipsychotic drugs aripiprazole, chlorprothixene plus metabolite, and quetiapine in cases with cause of death presumed to be unrelated to toxicity of these drugs were of about the same magnitude as published in vivo therapeutic plasma/serum values, suggesting that these drugs are not likely to be subject to major postmortem concentration increases in femoral blood.
Conclusion Reference concentrations of postmortem femoral blood values were estimated for aripiprazole, chlorprothixene, N-desmethylchlorprothixene, and quetiapine. One fatality due to chlorprothixene poisoning was reported as well as 13 fatalities due to multiple drug poisoning with 6 cases involving chlorprothixene and 7 cases involving quetiapine. The reference values were all of the same order of magnitude as previously reported in vivo literature values indicating no extensive postmortem redistribution for the investigated drugs.
1. Linnet, K. (2012) Postmortem drug concentration intervals for the non-intoxicated state - A review. Journal of Forensic and Legal Medicine, 19, 245–249. 2. Drummer, O.H. (2007) Post-mortem toxicology. Forensic Science International, 165, 199– 203. 3. Prouty, R.W., Anderson, W.H. (1990) The forensic science implications of site and temporal influences on postmortem blood-drug concentrations. Journal of Forensic Sciences, 35, 243–270. 4. Pounder, D.J., Jones, G.R. (1990) Post-mortem drug redistribution – a toxicological nightmare. Forensic Science International, 45, 253–263. 5. Druid, H., Holmgren, P. (1997) A compilation of fatal and control concentrations of drugs in postmortem femoral blood. Journal of Forensic Sciences, 42, 79 –87. 6. Reis, M., Aamo, T., Ahlner, J., Druid, H. (2007) Reference concentrations of antidepressants. A compilation of postmortem and therapeutic levels. Journal of Analytical Toxicology, 31, 254–264. 7. Linnet, K., Lang, L.M., Johansen, S.S. (2011) Postmortem femoral blood concentrations of amlodipine. Journal of Analytical Toxicology, 35, 227–231. 8. Linnet, K., Johansen, S.S. (2014) Postmortem femoral blood concentrations of risperidone. Journal of Analytical Toxicology, 38, 57 –60. 9. Vance, C., McIntyre, I.M. (2009) Postmortem tissue concentrations of olanzapine. Journal of Analytical Toxicology, 33, 15 –26. 10. Jo¨nsson, A.K., So¨derberg, C., Espnes, K.A., Ahlner, J., Eriksson, A., Reis, M., et al. (2014) Sedative and hypnotic drugs – fatal and non-fatal reference blood concentrations. Forensic Science International, 236, 138– 145. 11. Launiainen, T., Ojanpera¨, I. (2014) Drug concentrations in postmortem femoral blood compared with therapeutic concentrations in plasma. Drug Testing and Analysis, 6, 308– 316. 12. Jones, A.W., Holmgren, A. (2009) Concentration distributions of the drugs most frequently identified in post-mortem femoral blood representing all causes of death. Medicine, Science and the Law, 49, 257– 273. 13. Baselt, R.C. Disposition of Toxic Drugs and Chemicals in Man; 9th edition. Biomedical Publications, Seal Beach, CA, USA, 2011. 14. Molden, E., Lunde, H., Lunder, N., Refsum, H. (2006) Pharmacokinetic variability of aripiprazole and the active metabolite dehydroaripiprazole in psychiatric patients. Therapeutic Drug Monitoring, 28, 744– 749.
Postmortem Concentrations of Three Antipsychotics 43
15. Winek, C.L., Wahba, W.W., Winek, C.L., Jr, Balzer, T.W. (2001) Drug and chemical blood-level data 2001. Forensic Science International, 122, 107–123. 16. Schulz, M., Iwersen-Bergmann, S., Andresen, H., Schmoldt, A. (2012) Therapeutic and toxic blood concentrations of nearly 1,000 drugs and other xenobiotics. Critical Care, 16, R136. 17. DeVane, C.L., Nemeroff, C.B. (2001) Clinical pharmacokinetics of quetiapine: an atypical antipsychotic. Clinical Pharmacokinetics, 40, 509– 522. 18. Kirschbaum, K.M., Mu¨ller, M.J., Zernig, G., Saria, A., Mobascher, A., Malevani, J., et al. (2005) Therapeutic monitoring of aripiprazole by HPLC with column-switching and spectrophotometric detection. Clinical Chemistry, 51, 1718–1721. 19. Kirschbaum, K.M., Mu¨ller, M.J., Malevani, J., Mobascher, A., Burchardt, C., Piel, M., et al. (2008) Serum levels of aripiprazole and dehydroaripiprazole, clinical response and side effects. The World Journal of Biological Psychiatry, 9, 212– 218. 20. Bachmann, C.J., Rieger-Gies, A., Heinzel-Gutenbrunner, M., Hiemke, C., Remschmidt, H., Theisen, F.M. (2008) Large variability of aripiprazole and dehydroaripiprazole serum concentrations in adolescent patients with schizophrenia. Therapeutic Drug Monitoring, 30, 462–466. 21. Mallikaarjun, S., Salazar, D.E., Bramer, S.L. (2004) Pharmacokinetics, tolerability, and safety of aripiprazole following multiple oral dosing in normal healthy volunteers. The Journal of Clinical Pharmacology, 44, 179–187. 22. Seifert, S.A., Schwartz, M.D., Thomas, J.D. (2005) Aripiprazole (AbilifyTM ) overdose in a child. Clinical Toxicology, 43, 193– 195. 23. Christensen, H. (1974) Chlorprothixene and its metabolites in blood, liver, and urine from fatal poisoning. Acta Pharmacologica et Toxicologica, 34, 16 –26. 24. Poklis, A., Maginn, D., Mackell, M.A. (1983) Chlorprothixene and chlorprothixene-sulfoxide in body fluids from a case of drug overdose. Journal of Analytical Toxicology, 7, 29 –32. 25. Brooks, M.A., DiDonato, G., Blumenthal, H.P. (1985) Determination of chlorprothixene and its sulfoxide metabolite in plasma by highperformance liquid chromatography with ultraviolet and amperometric detection. Journal of Chromatography B: Biomedical Sciences and Applications, 337, 351–362. 26. Hasselstrøm, J., Linnet, K. (2004) Quetiapine serum concentrations in psychiatric patients: the influence of comedication. Therapeutic Drug Monitoring, 26, 486– 491. 27. Gerlach, M., Hu¨nnerkopf, R., Rothenho¨fer, S., Libal, G., Burger, R., Clement, H.-W., et al. (2007) Therapeutic drug monitoring of quetiapine in adolescents with psychotic disorders. Pharmacopsychiatry, 40, 72– 76. 28. Potkin, S.G., Thyrum, P.T., Alva, G., Bera, R., Yeh, C., Arvanitis, L.A. (2002) The safety and pharmacokinetics of quetiapine when coadministered with haloperidol, risperidone, or thioridazine. Journal of Clinical Psychopharmacology, 22, 121– 130. 29. Fabre, L.F.J., Arvanitis, L., Pultz, J., Jones, V.M., Malick, J.B., Slotnick, V.B. (1995) ICI 204,636, a novel, atypical antipsychotic: early indication of safety and efficacy in patients with chronic and subchronic schizophrenia. Clinical Therapeutics, 17, 366–378. 30. Beelen, A.P., Yeo, K.T., Lewis, L.D. (2001) Asymptomatic QTc prolongation associated with quetiapine fumarate overdose in a patient being treated with risperidone. Human & Experimental Toxicology, 20, 215–219.
44 Skov et al.
31. Harmon, T.J., Benitez, J.G., Krenzelok, E.P., Cortes-Belen, E. (1998) Loss of consciousness from acute quetiapine overdosage. Clinical Toxicology, 36, 599–602. 32. Pollak, P.T., Zbuk, K. (2000) Quetiapine fumarate overdose: clinical and pharmacokinetic lessons from extreme conditions. Clinical Pharmacology & Therapeutics, 68, 92 –97. 33. Hunfeld, N.G.M., Westerman, E.M., Boswijk, D.J., de Haas, J.A.M., van Putten, M.J.A.M., Touw, D.J. (2006) Quetiapine in overdosage: a clinical and pharmacokinetic analysis of 14 cases. Therapeutic Drug Monitoring, 28, 185– 189. 34. Young, A.C., Kleinschmidt, K.C., Wax, P.M. (2009) Late-onset seizures associated with quetiapine poisoning. Journal of Medical Toxicology, 5, 24 –26. 35. Anderson, D.T., Fritz, K.L. (2000) Quetiapine (Seroquelw) concentrations in seven postmortem cases. Journal of Analytical Toxicology, 24, 300– 304. 36. Parker, D.R., McIntyre, I.M. (2005) Case studies of postmortem quetiapine: therapeutic or toxic concentrations? Journal of Analytical Toxicology, 29, 407– 412. 37. Langman, L.J., Kaliciak, H.A., Carlyle, S. (2004) Fatal overdoses associated with quetiapine. Journal of Analytical Toxicology, 28, 520– 525. 38. Wise, S., Jenkins, A.J. (2005) Disposition of quetiapine in biological specimens from postmortem cases. Journal of Forensic Sciences, 50, 209–214. 39. Mainland, M.K., Wagner, M.A., Gock, S.B., Wong, S.H. (2001) Quetiapine-related fatalities. Journal of Analytical Toxicology, 25, 381–382. 40. Carstairs, S.D., Williams, S.R. (2005) Overdose of aripiprazole, a new type of antipsychotic. The Journal of Emergency Medicine, 28, 311– 313. 41. Nudelman, E., Vinuela, L.M., Cohen, C.I. (1998) Safety in overdose of quetiapine: a case report. Journal of Clinical Psychiatry, 59, 433. 42. Sing, K.J., Ramaekers, G.M.G.I., Harten, P.N.V. (2002) Neuroleptic malignant syndrome and quetiapine. The American Journal of Psychiatry, 159, 149–150. 43. Nielsen, M.K.K., Johansen, S.S. (2012) Simultaneous determination of 25 common pharmaceuticals in whole blood using ultraperformance liquid chromatography-tandem mass spectrometry. Journal of Analytical Toxicology, 36, 497–506. 44. Bjørk, M.K., Simonsen, K.W., Andersen, D.W., Dalsgaard, P.W., Sigurardo´ttir, S.R., Linnet, K., et al. (2013) Quantification of 31 illicit and medicinal drugs and metabolites in whole blood by fully automated solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry. Analytical & Bioanalytical Chemistry, 405, 2607–2617. 45. Ferner, R.E. (2008) Post-mortem clinical pharmacology. British Journal of Clinical Pharmacology, 66, 430–443. 46. Hilberg, T., Rogde, S., Mørland, J. (1999) Postmortem drug redistribution-human cases related to results in experimental animals. Journal of Forensic Sciences, 44, 3– 9. 47. Rodda, K.E., Drummer, O.H. (2006) The redistribution of selected psychiatric drugs in post-mortem cases. Forensic Science International, 164, 235– 239. 48. Saar, E., Beyer, J., Gerostamoulos, D., Drummer, O.H. (2012) The timedependant post-mortem redistribution of antipsychotic drugs. Forensic Science International, 222, 223–227.
Article
Postmortem Femoral Blood Reference Concentrations of Aripiprazole, Chlorprothixene, and Quetiapine Louise Skov*, Sys Stybe Johansen and Kristian Linnet Section of Forensic Chemistry, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V’s Vej 11, DK-2100 Copenhagen Ø, Denmark *Author to whom correspondence should be addressed. Email: [email protected]
Postmortem femoral blood concentrations of the antipsychotic drugs aripiprazole, chlorprothixene and its metabolite, and quetiapine were determined by LC–MS-MS in 25 cases for aripiprazole and 60 cases each for chlorprothixene and quetiapine. For cases where the cause of death was not related to the considered drugs, the following blood concentration intervals (10 –90 percentiles) were observed: 0.049 – 0.69 mg/kg for aripiprazole, 0.006 – 0.24 mg/kg for chlorprothixene, and 0.006 – 0.37 mg/kg for quetiapine. These concentration ranges largely correspond to therapeutic plasma levels observed in vivo suggesting no or only limited postmortem redistribution for aripiprazole, chlorprothixene with metabolite, and quetiapine in these cases. One fatality caused by chlorprothixene with a blood level of 0.90 mg/kg was recorded, and in six cases chlorprothixene was judged to be contributing to death with concentrations 0.43– 0.91 mg/kg. No fatalities exclusively ascribed to the two other drugs were observed, but aripiprazole was considered to be contributing to death in one case (1.9 mg/kg) and quetiapine in seven cases with concentrations 0.35 – 10.0 mg/kg. The presented values may serve as a reference for judgment of postmortem cases with presence of these antipsychotics.
Introduction In postmortem cases, blood levels of drugs may not equal in vivo concentrations in plasma because of postmortem redistribution and differences between plasma and whole blood concentrations (1 –4). Thus, it has been recommended to estimate reference levels from postmortem cases since postmortem reference concentrations are a valuable asset for determining cause of death (5, 6). Druid and Holmgren and later Reis et al. compiled postmortem drug levels and divided them into three categories: A: concentrations in cases ascribed to fatal intoxication with the drug as the sole cause of death, B: concentrations where the drug is considered a contributing cause of death, and C: concentrations observed when the drug is not considered to be directly related to the cause of death, e.g., suicide by hanging or shooting (5, 6). This categorization is primarily based on circumstances and not on drug concentrations. Postmortem reference values have also been reported in other studies, e.g., amlodipine (7), risperidone (8), olanzapine (9), and more recently for 16 different sedative and hypnotic drugs (10). In other studies, postmortem concentrations were reported for 25 and 129 drugs, respectively, including several antipsychotics, but there were no categorization in A –C case types (11, 12). Here, we present concentration ranges in postmortem blood for aripiprazole, chlorprothixene, and quetiapine. The results were categorized A – C and compared with previously published findings. The three drugs investigated here are all antipsychotic drugs used primarily in the treatment
of schizophrenia and bipolar disorder. The recommended daily doses for aripiprazole are 10 –30 mg orally, for chlorprothixene 20– 600 mg in two divided portions either by oral or intramuscular routes, and for quetiapine 150 –800 mg in two or three divided oral portions (13). During therapy, the average plasma/serum levels for aripiprazole have been measured up to 0.96 mg/L (14), for chlorprothixene up to 0.3 mg/L (15, 16), and for quetiapine up to 1.1 mg/L (17) as listed in Table I. Concerning aripiprazole, adults or children who ingested acute overdoses have suffered from mild sedation (40) to coma (22), but so far no deaths have been recorded, even in cases where the concentration were elevated by up to 3- to 4-fold over normal therapeutic levels suggesting that aripiprazole has a wide therapeutic index. The side effects of chlorprothixene can be so substantial that normally a full effective dose cannot be given, so chlorprothixene is often given in combination with other more potent antipsychotic drugs to allow remission of the psychotic disorder. Overdose symptoms can be confusion, hypotension, and tachycardia (13) and several fatalities have been reported with concentrations in postmortem blood ranging from 0.1 to 7.0 mg/L (5, 23 – 25). Overdose symptoms for quetiapine poisoning can include drowsiness, disorientation (41), neuroleptic malignant syndrome (42), EKG abnormalities (30), together with tachycardia, and coma (31). Several fatalities have been reported with postmortem blood concentrations ranging from 0.28 to 170 mg/L (35 –39).
Experimental Postmortem samples Screening for aripiprazole, quetiapine, chlorprothixene, and its active N-desmethylmetabolite is part of the routine toxicological investigations of forensic cases. Aripiprazole was detected in 25 cases in the period 2006 – 2013, chlorprothixene in 60 cases, and quetiapine in 60 cases for the period 2009 – 2012. Dosing details were not available. Autopsies were performed within 1 – 4 days after the bodies arrived at the Department of Forensic Medicine; storage was at 58C. Blood was drawn from the femoral vein at the beginning of the autopsy after the body was opened without ligation of the iliac vein. The blood samples were preserved with 1% sodium fluoride and stored at 2208C until analysis.
Analytical method Aripiprazole cases from 2006 to 2011 (N ¼ 16) and all chlorprothixene with metabolite (N ¼ 60), and quetiapine (N ¼ 60) cases were quantified by a previously published method (43) involving liquid – liquid extraction, separation by ultra-high-performance liquid chromatography and detection by tandem mass
# The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected]
Table I. In Vivo and Postmortem Concentrations of Aripiprazole, Chlorprothixene, N-Desmethylchlorprothixene, and Quetiapine Reported in the Literature (mg/L or mg/kg)
Table II. Postmortem Blood Concentrations of Aripiprazole, Chlorprothixene, N-Desmethylchlorprothixene, and Quetiapine for Categories A, B, and C in Present Study (mg/kg)
Matrix
Categorya
Aripiprazole Serum Serum Serum Serum Plasma Serum Chlorprothixen Plasma Plasma/serum Postmortem blood Postmortem blood Postmortem blood Postmortem blood N-Desmethylchlorprothixene Postmortem blood Postmortem blood Quetiapine Plasma Serum Plasma Plasma Serum Plasma Serum Serum Serum Serum Postmortem heart blood Postmortem femoral blood Postmortem heart blood Postmortem heart blood Postmortem cavity blood Postmortem femoral blood
Therapeutic level
Clinical intoxication Fatalities cases/B postmortem cases
0.23 –0.96 [118] 0.11 –0.55 [27] 0 –0.87 [164] 0.04 –0.65 [33] 0.10 –0.45 [48]
(14) (18) (19) (20) (21) (22)
1.4 [1] 0.02 –0.30* 0.04 –0.30* 0.2 [1]
0.4 –0.8* 0.60 –7.0 [2] 0.60 –2.0[2]
0 –1.1 [12] 0 –0.86 [53] 0.02 –0.88 [21] 0.59 –0.92 [36] 0.14 –0.37 [11] 1.8 [1] 12.7 [1] 1.8 [1] 1.1 –8.8 [14] 8.7 [1] 0.43 –49 [5] 1.3 –30 [8]
Ref.
1.6 –1.7 [2] 0.4 [1] 0.1 [1] 0.13– 0.25 [2]
(16) (15) (5) (23) (24) (25)
0.3 [1] 0.06– 0.26 [2]
(23) (25)
(17) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) 2.6 –14 [2] (36) 7.2 –16 [3] (37) 0.72– 18.4 [12] (38) 170 [1] (39) 0.28– 19.3 [12] (38)
Number of observations, N, are indicated by [ ]. N not available indicated by asterisk.
spectrometry. Aripiprazole was not originally included in the method but added later. Reference material of aripiprazole was obtained from Bristol-Myers Squibb Company (Syracuse, New York, USA). All blood samples are initially weighed; hence, the results are given in mg/kg. The detection was performed by positive electrospray ionization operating in multiple reaction monitoring (MRM) mode with two MRM transitions of each drug. The published method was validated for 25 common pharmaceuticals including chlorprothixene with metabolite and quetiapine (43). A supplementary validation for aripiprazole showed a linear range from 0.002 to 1.0 mg/kg (LOQ 0.002 mg/kg) and a process efficiency of 60%. The intermediary precisions were 20 and 17% with bias against the spiked level of ,2% for the low and high controls at 0.020 and 0.30 mg/kg. Aripiprazole samples from 2012 (N ¼ 9) were measured by another method, which is under preparation for publication. The sample preparation was based on solid-phase extraction (SPE) that was described in detail in (44), while the UHPLC –MS-MS conditions are as described in (43) with the following transitions for aripiprazole: 448!285 and 448!176 with a cone voltage of 49 V and collision energy at 25 and 31 eV, respectively. The new method had a linear range from 0.002 to 2.5 mg/kg (LOQ 0.002 mg/kg) and a process efficiency of 38%, while the intermediary precision was 13 and 14% with bias of 6 and 16% for the low and high controls at 0.020 and 0.30 mg/kg, respectively. The metabolite 42 Skov et al.
N
Aripiprazole A – B 1 C 20 Chlorprothixene A 1 B 6 C 51 N-Desmethylchlorprothixene A 1 B 6 C 51 Chlorprothixene/metabolite ratio A 1 B 6 C 51 Quetiapine A – B 7 C 51
Range
Median
10– 90 percentile
– 1.9 0.015 –0.91
– 1.9 0.20
– – 0.049 –0.69
0.90 0.43 –0.91 0.002 –0.43
0.90 0.52 0.042
– – 0.006 –0.24
0.51 0.23 –0.93 0.002 –0.20
0.51 0.24 0.033
– – 0.006 –0.086
1.76 0.87 –2.21 0.50 –8.00
1.76 1.87 1.53
– – 0.64 –4.21
– 0.35 –10.0 0.003 –0.80
– 1.30 0.13
– – 0.006 –0.37
a A: drug is considered the sole cause of death; B: drug is considered a contributing cause of death; C: drug is not considered to be directly related to the cause of death.
dehydroaripiprazole was not quantified, but separation between the parent compound and metabolite was achieved with the chromatographic system, so no interference occurred for the aripiprazole determinations.
Results and discussion The concentration data are given in Table II for all the drugs studied separated into A –C categories.
Aripiprazole For the 25 aripiprazole cases, there was a single category B case, 20 category C cases, and 4 cases with uncertain cause of death (U). The concentration of the single aripiprazole category B case, 1.9 mg/kg, is of the same order of magnitude as observed in a clinical intoxication case (22). Besides aripiprazole poisoning, the deceased had a toxic/fatal methadone level of 1.4 mg/kg. For the 20 C cases, the cause of death was poisoning with other drugs (13), suffocation (1), stabbing (1), and natural causes for the remaining 5. The concentration levels of the category C cases (N ¼ 20), which ranged from 0.015 to 0.91 mg/kg, were in the same order of magnitude as reported in vivo therapeutic plasma or serum levels from below LOQ to 0.96 mg/L (14, 18 – 21). The 10 – 90 percentile for aripiprazole was determined to 0.049 –0.69 mg/kg.
Chlorprothixene There were 1 A case, 6 B cases in addition to 51 C cases. The latter included 33 cases of poisoning with other psychoactive drugs and/or ethanol, 3 drowning and suffocation cases, and 15 cases with a natural cause of death. For two cases, the cause of death was uncertain (U). The concentration of the A case, 0.90 mg/kg, was of the same order of magnitude as values given in the literature for fatalities
with chlorprothixene present as the only drug (5, 23 – 25). For the six category, B cases the concentration range 0.43 – 0.91 mg/kg was about the same as the plasma/serum range reported for clinical intoxication cases 0.4 – 0.8 mg/L (15) and the range for blood in postmortem cases 0.60 – 7.0 mg/kg (5, 23). All B cases involved multiple drugs, and four of the six cases involved benzodiazepines in therapeutic levels, one case involved opioids in therapeutic levels, five cases involved antidepressants up to toxic levels, two cases involved other antipsychotic drugs at therapeutic to toxic levels, and one case included the antihistamine hydroxyzine at a toxic level. The concentrations of the category C cases (N ¼ 51), which ranged from 0.002 to 0.43 mg/kg, were of the same order of magnitude as stated in vivo therapeutic plasma/serum levels 0.02 – 0.3 mg/L (15, 16). The 10 – 90 percentile was determined to 0.006 –0.24 mg/kg. The A category case had a drug/metabolite ratio of 1.76, and the medians for the B and C categories were 1.87 and 1.53, respectively. In the literature, three chlorprothixene postmortem overdose cases have been reported with an average drug/metabolite ratio of 1.31 (23, 25).
This is in opposition to the majority of antipsychotic drugs that tend to exhibit increases of postmortem values. Even though postmortem redistribution generally is more pronounced in heart than in femoral blood, postmortem redistribution has previously been reported in femoral blood as well (46, 47). On the other hand, quetiapine has recently been reported not to undergo postmortem redistribution (48).
Quetiapine For the 60 quetiapine cases, there were no cases where quetiapine poisoning was classified as the sole cause of death, but seven cases were considered category B cases, where quetiapine was a contributing factor to death. The cause of death for all the B cases was determined as multiple drug poisoning. In five cases, opioids were present in therapeutic to possible lethal levels, five cases involved multiple antipsychotic drugs up to toxic levels, four cases had benzodiazepines levels from therapeutic to toxic levels, and four cases had antidepressants from therapeutic to elevated levels. Fifty-one cases were considered C cases with cause of death unrelated to quetiapine. These cases included 32 cases of poisoning with other psychoactive drugs and/or ethanol, 11 cases of natural death, 3 cases of suffocation, 2 cases of drowning, 2 cases of hanging, and a single case of carbon monoxide poisoning. The cause of death for the two cases left was classified as uncertain. The seven category B cases had concentrations 0.35 – 10.0 mg/kg, which were below or in the range of serum/plasma values for clinical intoxication cases, 1.1 –12.7 mg/L (30 –34). The concentrations of the category C cases (N ¼ 51), which ranged from 0.003 to 0.80 mg/kg, were in the same range as reported in vivo therapeutic values, from below LOQ to 0.92 mg/L (17, 26 – 29). The 10 – 90 percentile was determined to 0.006 – 0.37 mg/kg.
References
Postmortem redistribution Antipsychotic drugs usually have high volumes of distribution with high tissue concentrations, which are considered to predispose to postmortem redistribution (45). However, concentrations of the three antipsychotic drugs aripiprazole, chlorprothixene plus metabolite, and quetiapine in cases with cause of death presumed to be unrelated to toxicity of these drugs were of about the same magnitude as published in vivo therapeutic plasma/serum values, suggesting that these drugs are not likely to be subject to major postmortem concentration increases in femoral blood.
Conclusion Reference concentrations of postmortem femoral blood values were estimated for aripiprazole, chlorprothixene, N-desmethylchlorprothixene, and quetiapine. One fatality due to chlorprothixene poisoning was reported as well as 13 fatalities due to multiple drug poisoning with 6 cases involving chlorprothixene and 7 cases involving quetiapine. The reference values were all of the same order of magnitude as previously reported in vivo literature values indicating no extensive postmortem redistribution for the investigated drugs.
1. Linnet, K. (2012) Postmortem drug concentration intervals for the non-intoxicated state - A review. Journal of Forensic and Legal Medicine, 19, 245–249. 2. Drummer, O.H. (2007) Post-mortem toxicology. Forensic Science International, 165, 199– 203. 3. Prouty, R.W., Anderson, W.H. (1990) The forensic science implications of site and temporal influences on postmortem blood-drug concentrations. Journal of Forensic Sciences, 35, 243–270. 4. Pounder, D.J., Jones, G.R. (1990) Post-mortem drug redistribution – a toxicological nightmare. Forensic Science International, 45, 253–263. 5. Druid, H., Holmgren, P. (1997) A compilation of fatal and control concentrations of drugs in postmortem femoral blood. Journal of Forensic Sciences, 42, 79 –87. 6. Reis, M., Aamo, T., Ahlner, J., Druid, H. (2007) Reference concentrations of antidepressants. A compilation of postmortem and therapeutic levels. Journal of Analytical Toxicology, 31, 254–264. 7. Linnet, K., Lang, L.M., Johansen, S.S. (2011) Postmortem femoral blood concentrations of amlodipine. Journal of Analytical Toxicology, 35, 227–231. 8. Linnet, K., Johansen, S.S. (2014) Postmortem femoral blood concentrations of risperidone. Journal of Analytical Toxicology, 38, 57 –60. 9. Vance, C., McIntyre, I.M. (2009) Postmortem tissue concentrations of olanzapine. Journal of Analytical Toxicology, 33, 15 –26. 10. Jo¨nsson, A.K., So¨derberg, C., Espnes, K.A., Ahlner, J., Eriksson, A., Reis, M., et al. (2014) Sedative and hypnotic drugs – fatal and non-fatal reference blood concentrations. Forensic Science International, 236, 138– 145. 11. Launiainen, T., Ojanpera¨, I. (2014) Drug concentrations in postmortem femoral blood compared with therapeutic concentrations in plasma. Drug Testing and Analysis, 6, 308– 316. 12. Jones, A.W., Holmgren, A. (2009) Concentration distributions of the drugs most frequently identified in post-mortem femoral blood representing all causes of death. Medicine, Science and the Law, 49, 257– 273. 13. Baselt, R.C. Disposition of Toxic Drugs and Chemicals in Man; 9th edition. Biomedical Publications, Seal Beach, CA, USA, 2011. 14. Molden, E., Lunde, H., Lunder, N., Refsum, H. (2006) Pharmacokinetic variability of aripiprazole and the active metabolite dehydroaripiprazole in psychiatric patients. Therapeutic Drug Monitoring, 28, 744– 749.
Postmortem Concentrations of Three Antipsychotics 43
15. Winek, C.L., Wahba, W.W., Winek, C.L., Jr, Balzer, T.W. (2001) Drug and chemical blood-level data 2001. Forensic Science International, 122, 107–123. 16. Schulz, M., Iwersen-Bergmann, S., Andresen, H., Schmoldt, A. (2012) Therapeutic and toxic blood concentrations of nearly 1,000 drugs and other xenobiotics. Critical Care, 16, R136. 17. DeVane, C.L., Nemeroff, C.B. (2001) Clinical pharmacokinetics of quetiapine: an atypical antipsychotic. Clinical Pharmacokinetics, 40, 509– 522. 18. Kirschbaum, K.M., Mu¨ller, M.J., Zernig, G., Saria, A., Mobascher, A., Malevani, J., et al. (2005) Therapeutic monitoring of aripiprazole by HPLC with column-switching and spectrophotometric detection. Clinical Chemistry, 51, 1718–1721. 19. Kirschbaum, K.M., Mu¨ller, M.J., Malevani, J., Mobascher, A., Burchardt, C., Piel, M., et al. (2008) Serum levels of aripiprazole and dehydroaripiprazole, clinical response and side effects. The World Journal of Biological Psychiatry, 9, 212– 218. 20. Bachmann, C.J., Rieger-Gies, A., Heinzel-Gutenbrunner, M., Hiemke, C., Remschmidt, H., Theisen, F.M. (2008) Large variability of aripiprazole and dehydroaripiprazole serum concentrations in adolescent patients with schizophrenia. Therapeutic Drug Monitoring, 30, 462–466. 21. Mallikaarjun, S., Salazar, D.E., Bramer, S.L. (2004) Pharmacokinetics, tolerability, and safety of aripiprazole following multiple oral dosing in normal healthy volunteers. The Journal of Clinical Pharmacology, 44, 179–187. 22. Seifert, S.A., Schwartz, M.D., Thomas, J.D. (2005) Aripiprazole (AbilifyTM ) overdose in a child. Clinical Toxicology, 43, 193– 195. 23. Christensen, H. (1974) Chlorprothixene and its metabolites in blood, liver, and urine from fatal poisoning. Acta Pharmacologica et Toxicologica, 34, 16 –26. 24. Poklis, A., Maginn, D., Mackell, M.A. (1983) Chlorprothixene and chlorprothixene-sulfoxide in body fluids from a case of drug overdose. Journal of Analytical Toxicology, 7, 29 –32. 25. Brooks, M.A., DiDonato, G., Blumenthal, H.P. (1985) Determination of chlorprothixene and its sulfoxide metabolite in plasma by highperformance liquid chromatography with ultraviolet and amperometric detection. Journal of Chromatography B: Biomedical Sciences and Applications, 337, 351–362. 26. Hasselstrøm, J., Linnet, K. (2004) Quetiapine serum concentrations in psychiatric patients: the influence of comedication. Therapeutic Drug Monitoring, 26, 486– 491. 27. Gerlach, M., Hu¨nnerkopf, R., Rothenho¨fer, S., Libal, G., Burger, R., Clement, H.-W., et al. (2007) Therapeutic drug monitoring of quetiapine in adolescents with psychotic disorders. Pharmacopsychiatry, 40, 72– 76. 28. Potkin, S.G., Thyrum, P.T., Alva, G., Bera, R., Yeh, C., Arvanitis, L.A. (2002) The safety and pharmacokinetics of quetiapine when coadministered with haloperidol, risperidone, or thioridazine. Journal of Clinical Psychopharmacology, 22, 121– 130. 29. Fabre, L.F.J., Arvanitis, L., Pultz, J., Jones, V.M., Malick, J.B., Slotnick, V.B. (1995) ICI 204,636, a novel, atypical antipsychotic: early indication of safety and efficacy in patients with chronic and subchronic schizophrenia. Clinical Therapeutics, 17, 366–378. 30. Beelen, A.P., Yeo, K.T., Lewis, L.D. (2001) Asymptomatic QTc prolongation associated with quetiapine fumarate overdose in a patient being treated with risperidone. Human & Experimental Toxicology, 20, 215–219.
44 Skov et al.
31. Harmon, T.J., Benitez, J.G., Krenzelok, E.P., Cortes-Belen, E. (1998) Loss of consciousness from acute quetiapine overdosage. Clinical Toxicology, 36, 599–602. 32. Pollak, P.T., Zbuk, K. (2000) Quetiapine fumarate overdose: clinical and pharmacokinetic lessons from extreme conditions. Clinical Pharmacology & Therapeutics, 68, 92 –97. 33. Hunfeld, N.G.M., Westerman, E.M., Boswijk, D.J., de Haas, J.A.M., van Putten, M.J.A.M., Touw, D.J. (2006) Quetiapine in overdosage: a clinical and pharmacokinetic analysis of 14 cases. Therapeutic Drug Monitoring, 28, 185– 189. 34. Young, A.C., Kleinschmidt, K.C., Wax, P.M. (2009) Late-onset seizures associated with quetiapine poisoning. Journal of Medical Toxicology, 5, 24 –26. 35. Anderson, D.T., Fritz, K.L. (2000) Quetiapine (Seroquelw) concentrations in seven postmortem cases. Journal of Analytical Toxicology, 24, 300– 304. 36. Parker, D.R., McIntyre, I.M. (2005) Case studies of postmortem quetiapine: therapeutic or toxic concentrations? Journal of Analytical Toxicology, 29, 407– 412. 37. Langman, L.J., Kaliciak, H.A., Carlyle, S. (2004) Fatal overdoses associated with quetiapine. Journal of Analytical Toxicology, 28, 520– 525. 38. Wise, S., Jenkins, A.J. (2005) Disposition of quetiapine in biological specimens from postmortem cases. Journal of Forensic Sciences, 50, 209–214. 39. Mainland, M.K., Wagner, M.A., Gock, S.B., Wong, S.H. (2001) Quetiapine-related fatalities. Journal of Analytical Toxicology, 25, 381–382. 40. Carstairs, S.D., Williams, S.R. (2005) Overdose of aripiprazole, a new type of antipsychotic. The Journal of Emergency Medicine, 28, 311– 313. 41. Nudelman, E., Vinuela, L.M., Cohen, C.I. (1998) Safety in overdose of quetiapine: a case report. Journal of Clinical Psychiatry, 59, 433. 42. Sing, K.J., Ramaekers, G.M.G.I., Harten, P.N.V. (2002) Neuroleptic malignant syndrome and quetiapine. The American Journal of Psychiatry, 159, 149–150. 43. Nielsen, M.K.K., Johansen, S.S. (2012) Simultaneous determination of 25 common pharmaceuticals in whole blood using ultraperformance liquid chromatography-tandem mass spectrometry. Journal of Analytical Toxicology, 36, 497–506. 44. Bjørk, M.K., Simonsen, K.W., Andersen, D.W., Dalsgaard, P.W., Sigurardo´ttir, S.R., Linnet, K., et al. (2013) Quantification of 31 illicit and medicinal drugs and metabolites in whole blood by fully automated solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry. Analytical & Bioanalytical Chemistry, 405, 2607–2617. 45. Ferner, R.E. (2008) Post-mortem clinical pharmacology. British Journal of Clinical Pharmacology, 66, 430–443. 46. Hilberg, T., Rogde, S., Mørland, J. (1999) Postmortem drug redistribution-human cases related to results in experimental animals. Journal of Forensic Sciences, 44, 3– 9. 47. Rodda, K.E., Drummer, O.H. (2006) The redistribution of selected psychiatric drugs in post-mortem cases. Forensic Science International, 164, 235– 239. 48. Saar, E., Beyer, J., Gerostamoulos, D., Drummer, O.H. (2012) The timedependant post-mortem redistribution of antipsychotic drugs. Forensic Science International, 222, 223–227.
