One Fatal and One Nonfatal Intoxication with

Journal of Analytical Toxicology, Vol. 20, September 1996

One Fatal and One Nonfatal Intoxication with Tranylcypromine.Absenceof Amphetaminesas Metabolites Stefanie Iwersen

and

Achim Schmoldt

Department of LegalMedicine, Universityof Hamburg, Butenfeld 34, D-22529 Hamburg, Germany

Abstract

!

Materials

Two very different cases of overdose with tranylcypromine are presented. One clinical case involving the ingestion of 400 mg tranylcypromine with suicidal intention and one fatality with a suspicion of possible tranylcypromine overdose were examined. Both casesshowed similar blood concentrations (0.5 and 0.7 rag/L, respectively), but the clinical case exhibited only mild symptoms of intoxication. The fatality showed no other drugs that could provide an explanation for the death of a 40-year-old male except tranylcypromine. Consideration of the drug concentrations in the fatality in relation to the case findings and other reported data indicates the tranylcypromine overdose as the probable cause of death, despite the low blood concentration. In addition, we looked for evidence of amphetamine as a putative metabolite in both cases. No amphetamines were detected in the overdose cases reported here.

Introduction

Tranylcypromine is a monoamine oxidase (MAO) inhibitor that is commonly used in the treatment of depression, especially in patients who do not respond to other antidepressants. The irreversible inhibition of monoamine degradation is responsible for the antidepressive effect, but it can also cause interaction with sympathomimetics or with tyramine from food. Symptoms of interaction or overdose are hypertensive crisis, hyperreflexia, shock, and convulsions (1-4). The metabolic conversion of tranylcypromine to amphetamine has been proposed by Youdhim et al. (5). This is a possible explanation for symptoms in cases of overdose or reports of tranylcypromine abuse (6). On the other hand, Riederer et al. (7) could not detect any amphetamines at therapeutic dosage of tranylcypromine. Although suicide with antidepressants occurs quite often, only three reports (8-10) gave blood concentrations of tranylcypromine. We report here on toxicologicaldata of one fatal and one nonfatal case of tranylcypromine overdose. In addition, we investigated whether the potential metabolites of tranylcypromine, amphetamine or methamphetamine could be found.

Tranylcypromine sulfate racemate was donated by Procter & Gamble (Weiterstadt, Germany). Methylenedioxymethamphetamine (MDMA)and amphetamine-d3, which were used as internal standards, were obtained from Sigma (Deisenhofen, Germany). Hepafluorobutyric anhydride (HFBA)was purchased from Fluka (Buchs, Switzerland). All other chemicals and reagents were of analytical grade and were used as purchased.

Methods

Systematic toxicological analysis Urine samples were screened for basic drugs and drugs of abuse by immunoassay using the Syva ETS (Darmstadt, Germany) and Abbott ADx (Wiesbaden-Delkenheim, Germany) systems according to the manufacturers instructions. Further screening for "general unknown" drugs was performed after alkaline or acid liquid-liquid or solid-phase extraction (SPE) using thin-layer chromatography (TLC) (11), GC, gas chromatography-mass spectrometry (GC-MS) (12), and highperformance liquid chromatography (HPLC) (13). Ethanol was determined in blood and urine samples by GC-flame-ionization detection (FID) using a column packed with 0.2% Carbowax 1500 on a 60/80 mesh Graphpac (Restek, Bad Soden, Germany).

Determination of tranylcypromine Blood and urine samples were diluted with an equal amount of water; solid-tissue samples were minced and homogenized with twice as much water. After dilution, blood and solid samples were ultrasonicated for 30 rain, then centrifuged. The supernatant was extracted according to the method that Cody and Schwarzhoff (14) used for the determination of amphetamines in urine. The samples were extracted at pH 11 with 1-chlorobutane. The organic phase was re-extracted with 0.15M H2SO4.The aqueous phase was transferred, adjusted to pH 11, and extracted again with 1-chlorobutane. Isopropanolic HCI (200 ]~L; Merck, Darmstadt, Germany) was added to the

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301

Journal of Analytical Toxicology, Vol. 20, September 1996

Table I. Toxicological Data of Blood Concentrations Following Fatal and Nonfatal Tranylcypromine Overdose Tranylcypromine concentration (mg/L)

Outcome

Dose (mg)

Circumstances

Other drugs

Case 1

Blood, 0.5 Urine, 2.4

Survival; pulse 115/min; no severesymptoms

400

gastric lavage 3 h after ingestion

Not detected

Case 2

Blood, 0.7 Liver, 1.9 Urine, 238.0

Death; survival time unknown

400-700

unknown

BAC*, 0 mg/dL UAC, 150 mg/dL

Reference 5

Plasma, 0.93

Survival; pulse 120/min; BP 140/100; confusion, dilated pupils

250

admission to hospital 22h after ingestion; Diazepam and Chlopromazine were administered

not detected

Reference 8

Heart blood, 5.0 lliac blood, 9.1 Liver, 21.0

Death; survival time, 6 h

unknown

unknown

Diazepam

Reference8

Blood, 1.7 Urine, 50.8

Death; survival time, 48 h

unknown

unknown

not detected

Reference9

Blood, 3.7 Urine, 25.0

Death; survival time unknown

300

unknown

Dextropropoxyphen d-lsoephedrine

Reference 10

Blood, 0.25 Liver, 13.0

Death; survival time unknown

850

unknown

not detected

*Abbreviations: BAC = blood alcohol concentration; UAC = urine alcohol concentration; BP = blood pressure.

Calibration curve

O

~-C~HOH-NH2 Tranylcypromine

OH2-CH- CH3 NH2 Amphetamine

@-C~Ho-/HCH-NH-(~-CH 3 ,~,'-Acetv[tranylcypromine

@-C~-

,CH-CH3 ,NH-C~C

Selegetine

OH3

"OH

Figure 1. Chemical structuresof tranylcypromine,N-acetyltranylcypromine, amphetamine, and selegine.

organic phase, and the extract was dried at 40~ under a slow stream of nitrogen. Ethyl acetate (100 ilL) and HFBA (50 ilL) were added to the residue. The solution was heated for 30 rain at 70~ After cooling to room temperature, the mixture was evaporated to dryness under a stream of nitrogen. The sample was reconstituted with 50 ~L ethyl acetate, and 1 pL was injected in splitless mode into a Hewlett Packard (B6blingen, Germany) model 5890 GC coupled to a HP model 5972 mass selective detector. Helium was used as the carrier gas at a flow rate of 1 mL/min. A (5% phenyl)-methylpolysiloxane capillary column (HP-5MS, 30 m x 0.25-ram i.d, 0.25-pro film thickness) was used. Operating temperatures for the injector and the detector were 200~ and 280~ respectively. Oven temperature was programmed as follows: 130~ for 3 rain, 4~ to 146~ 146~ for 4 rain, 30~ to 260~ and held for 10 rain.

302

Calibration curves for tranylcypromine, amphetamine, and methamphetamine were determined with 1 mg/L MDMA or amphetamine-d3 as internal standard. The ratios of the peak areas of amphetamine, methamphetamine, and tranylcypromine to MDMA or amphetamine-d:~ were used to calculate the concentration of the analytes in specimens. Standard calibration curves were linear over the range of 0.1 to 100 mg/L. The limit of quantitation was approximately 0.06 mg/L for tranylcypromine and 0.02 mg/L for amphetamine and methamphetamine. Both internal standards were used alternately to ensure that possibly detected traces of amphetamine did not result from degradation or contamination of amphetamine-d3.

Case Reports Case 1 A 35-year-old male took 40 10-rag tranylcypromine tablets with the intention of committing suicide. Approximately 3 h after ingestion he was taken to the hospital where gastric lavage was performed immediately. He developed mild tachycardia (115 beats/rain) and was sweating profusely. The patient was discharged the next day without any toxic symptoms. Directly after gastric lavage, tranylcyprornine concentration was determined to be 0.51 mg/L in plasma and 2.4 mg/L in urine. Case 2 A man known to be addicted to alcohol and different drugs

lournal of Analytical Toxicology, Vol, 20, September ] 996

and with a history of several suicide attempts in the past was found dead in his bed. An empty box of 100 tranylcypromine tablets and several alcoholic beverages were found near the decedent. The tablets had been prescribed by his doctor two weeks previously and were to be taken twice per day. The determined tranylcypromine concentrations are shown in Table I and compared with the data from Case 1 and other reported data from fatal and nonfatal overdose cases. Postmortem findings were as follows:the stomach was completely empty; the bladder contained 300 mL urine; the liver

showed a fatty degeneration due to known chronic alcohol abuse; lung and brain tissue were oedematous and congested; and the heart, coronary vessels, and aorta did not show any pathologic changes.

Results and Discussion

The cases show comparable blood concentrations but a completely different outcome. The tranylcypromine concentrations in our cases are between those previously reported for therapeutic doses (i.e., 0.6 to 0.12 ~bundance Ion 240.00 (23,,70 to 240.70): S378VHFB.D A rag/L) (15,16) and the few other fatalitieswith documented blood levels of tranylcypromine 100000 (Table I). For this reason, it was not clear if a tranylcypromine overdose was the actual 50000 cause of death. One possible explanation is the low levels might be attributable to postmortem degradation of tranylcypromine as 0 rime--> 4. 00 6.00 8.00 10.00 12.00 14.00 described by Yonemitsu et al. (17). They %bundance Ion 254.00 (253.70 to 254.70): S378VHFB.D showed that blood samples spiked with 14 60 B tranylcypromineand incubated at 37~ for 48 100000h showed a 58% decline in tranylcypromine blood concentration. In a case of combined 50000tranylcypromine and lithium overdose, the authors took blood samples from peripheral and central vessels at 0, 6, 24, 48, and 72 h 0 ~ime - - 9 .00 after starting the autopsy. Blood concentra6.00 8.00 I0.00 12.00 14.00 ~bundance Ion 116.00 (115.70 to i16.70): S378VHFB.D tion of tranylcypromine increased slightly 8.57 C during the first 24 h (1.3-1.6-fold), which 800000 was interpretated as a mild redistribution ef600000 fect (Vd = 1.11-5.68 L/kg), whereas the con400000 centration decreased within the next 48 h to levels that were much lower (25-80%) than 200000 those at the beginning. The decline was less 0 i . ' i .... i . . . . i , 9 ' ' pronounced in urine. Pime - - > 5.00 i0.00 15.00 20.00 However, the time after death was at least ~bundance Scan 411 (8.529 rain): S378VHFB.D 1:.6 D 48 h in this case, so degradation effects 900000 I might have contributed to the low tranyl800000 ] cypromine concentration. Tranylcypromine is readily absorbed from 700000 I the gastrointestinal tract and is rapidly elim600000 4 inated (tl/2, 1.5 h) (15). The MAO-inhibiting i effect of tranylcypromine is irreversible and 500000 1 therefore lasts considerably longer than blood concentrations of tranylcypromine can 400000 1 be determined. The extremely high tranyl300000 ] 69 cypromine concentration of the nearly neutral urine (pH 6.8) in Case 2 and the alcohol 200000 ] 169 concentrations in blood (0 mg/dL) and urine 238 lO, 100001 ] (150 mg/dL) point to a long time of survival. i I 3143 , Boniface (8) reported one case with a survival ! . . i "1 ,' 9 . 9 5'0 100 /z--> 150 200 250 300 350 time of 48 h (Table I), and Griffiths (18) reFigure2. Selected ion chromatograms obtained GC-MS analysis of the urine (Case2). A, m/z240 (no ported a case with a survival time of 19 h but did not include tranylcypromine blood amphetamine-HFBA; retention time, 5.7 min); B, m/z 254 (no methamphetamine-HFBA; retention time, concentrations. 7.8 min; internal standard, MDMA-HFBA; retention time, ]4.6 min); C, m/z I16 (tranylWe also investigated whether amphetcypromine-HFBA; retention time, 8.57 min); D, massspectra of tranylcypromine-HFBA. amines could be detected in these two casesof 303

Journal of AnalyticalToxicology,Vol. 20, September1996

overdose. Considering the increase in abuse of amphetamine and amphetamine derivatives, it is important to know which therapeutic drugs form amphetamines as metabolites. One example is the selective MAO [~-inhibitor selegeline, which can easily undergo sequential oxidative Nodesalkylation and yield R-(-)methamphetamine and R-(-)amphetamine (19)(Figure 1). Although both cases of overdose reported here showed positive immunological results for amphetamines (cross-reactivity of tranylcypromine was approximately 1%), neither amphetamine, methamphetamine, nor other amphetamine derivatives could be detected (Figure 2). This is in accordance with Riederer et al. (7) and Spahn-Langguth et al. (20). Only Youdhim et al. (5) detected high concentration of amphetamine and methamphetamine in a case of tranylcypromine overdose and postulated the metabolic formation of amphetamine from tranylcypromine by cleavage of the cyclopropyl ring. Furthermore, they showed the formation of methamphetamine, but not amphetamine, after incubation of rat liver homogenate together with tranylcypromine. However, this metabolic pathway seems to be rather unlikely because there is no report on N-methylation of amphetamine or tranylcypromine even at high concentration in vivo or in vitro. Moreover, we do not know an example of metabolic C-C bond cleavage without previous oxidation. Even in the case of pyrethroids with unsaturated side chains, the cyclopropyl ring can only be split by photo chemical reaction (21). These arguments and our findings do not support the hypothesis that amphetamine or methamphetamine might be metabolites of tranylcypromine.

7. 8. 9. 10. 11.

12. 13.

14. 15.

16.

17.

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