Forensic Science International 245 (2014) 87–91
Contents lists available at ScienceDirect
Forensic Science International journal homepage: www.elsevier.com/locate/forsciint
Postmortem distribution of guaifenesin concentrations reveals a lack of potential for redistribution Iain M. McIntyre a,*, Aylmer Navarrete a, Othon Mena b a b
Forensic Toxicology Laboratory, 5570 Overland Avenue, Suite 101, San Diego, CA 92123, USA County of San Diego Medical Examiner’s Office, 5570 Overland Avenue, Suite 101, San Diego, CA 92123, USA
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 August 2014 Received in revised form 14 October 2014 Accepted 16 October 2014 Available online 24 October 2014
Therapeutic (or non-toxic) postmortem guaifenesin blood and liver concentrations have not been previously described. Peripheral blood guaifenesin concentrations were compared to central blood and liver concentrations in eight medical examiner cases. Specimens were initially screened for alcohol and simple volatiles, drugs of abuse, alkaline, and acid/neutral drugs. Guaifenesin, when detected by the acid/ neutral drug screen, was subsequently confirmed and quantified by a high performance liquid chromatography procedure. Data suggest that postmortem guaifenesin peripheral blood concentrations may be considered non-toxic to at least 5.4 mg/L with liver concentrations to at least 7.0 mg/kg. Overall, guaifenesin concentrations ranged from 1.9 to 40 mg/L in peripheral blood, 2.2–150 mg/L in central blood, and 2.6–36 mg/kg in liver. The median guaifenesin central blood to peripheral blood ratio was 1.1 (N = 8). Similarly, liver to peripheral blood ratios showed a median value of 0.9 L/kg (N = 5). Given that a liver to peripheral blood ratio less than 5 L/kg is consistent with little to no propensity for postmortem redistribution, these data suggest that guaifenesin is not prone to substantial postmortem redistribution. Published by Elsevier Ireland Ltd.
Keywords: Guaifenesin Peripheral blood Central blood Liver Postmortem redistribution
1. Introduction Guaifenesin (Mucinex1, Robitussin1, Cheratussin1, Benylin1, DayQuil1), a guaiacol derivative, is used therapeutically as an expectorant [1,2] and a veterinary relaxant. It is also a metabolite of methocarbamol [3]. The expectorant properties of guaifenesin have endowed the drug with incorporation into numerous propriety preparations (tablet and syrups) which are commonly prescribed (together in combination with analgesics, antihistamines, antitussives or decongestants) at single doses of 50–200 mg and daily doses of up to 1200 mg, but may be used up to 2400 mg daily [1]. In clinical investigations, therapeutic plasma concentrations of guaifenesin following a dose of 200 mg (combined with 20 mg dextromethorphan) were reported to peak at 1–1.2 mg/L by 1 h [4]. Following a single oral dose of 600 mg, a mean peak blood concentration of 1.4 mg/L was attained at 15 min [5]. Guaifenesin is readily absorbed after oral administration, and it is metabolized by oxidation [2]. The estimated half-life of elimination is generally reported at about 1 h, but may increase to 5.3 h [3]. Therapeutic
* Corresponding author. Tel.: +1 858 694 2907; fax: +1 858 495 5383. E-mail address: [email protected] (I.M. McIntyre). http://dx.doi.org/10.1016/j.forsciint.2014.10.029 0379-0738/Published by Elsevier Ireland Ltd.
(or non-toxic) postmortem guaifenesin concentrations have not been described. Adverse effects of guaifenesin at higher dose levels include central nervous system depression [3]. Overdosage produces significant central nervous system (CNS) depression and guaifenesin may potentiate CNS depression when co-administered with other CNS depressants. Postmortem concentrations have been rarely described in blood or tissue. A concentration of 14 mg/L in blood (together with 3.0 mg/L hydrocodone) was reported in a single case of guaifenesin intoxication [6]. A woman died within 2 h of ingesting an overdose had a postmortem femoral blood level of 25 mg/L with an ethanol of 0.12 g/dL [7]. Another suicide involving ingestion of guaifenesin, together with diphenhydramine and chlorpheniramine, reported a postmortem heart blood guaifenesin concentration of 27 mg/L, urine 21 mg/L, bile 222 mg/ L, vitreous humor 7 mg/L, CSF 13 mg/L, and gastric contents 7700 mg [8]. Postmortem liver concentrations have not been described. To date, there has been no assessment or interpretation of the potential for guaifenesin postmortem redistribution. The study described herein examined eight postmortem cases for peripheral blood, central blood and liver concentrations from known positive guaifenesin cases. These investigations present data of postmortem distribution, and provide further insight on how liver concentrations may correlate with those of blood, and assist with
88
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
the interpretation of the drugs’ propensity for postmortem redistribution. 2. Experimental 2.1. Specimen collection and storage All specimens analyzed were collected at autopsy at the San Diego County Medical Examiner’s Office. Cases identified or suspected to be decomposed (as described in the Medical Examiner Investigation report, or at the time of autopsy) were not included. Autopsies were performed within 24–48 h after the reported time of death. Peripheral blood was drawn from the common iliac veins (blood returning from the leg and visually identified in the pelvis at autopsy) and stored in standard glass tubes containing sodium fluoride (100 mg) and potassium oxalate (20 mg). Central blood was collected from the heart or adjacent great vessels and placed in identical tubes. Sections of the upper right lobe of liver were collected and stored in a 16 ounce container without preservative. All samples were stored at 4 8C until analyzed. 2.2. Drug screening Drug screening for all cases included blood alcohol and simple volatiles by GC-FID headspace analysis, ELISA (cocaine metabolite, opiates, methamphetamine, benzodiazepines, cannabinoids, fentanyl, synthetic cannabinoids, oxycodone, methadone, zolpidem, carisoprodol, and buprenorphine) (Immunalysis Inc., CA), an alkaline drug screen by gas chromatography–mass spectrometry (GC–MS) following solid phase extraction, and an acid/neutral drug screen with high performance liquid chromatography (HPLC)photodiode array detection following specimen precipitation with acetonitrile. Guaifenesin, when detected by the acid/neutral drug screen, was subsequently confirmed and quantified by reextraction and re-analysis by a calibrated acid/neutral drug technique.
calibrators, controls and case specimens were pipetted into individual microcentrifuge tubes. 0.5 mL extraction solution (acetonitrile w/MPPH) was added to each tube and tubes were vortexed. Samples were allowed to sit at room temperature for 10 min to allow for protein precipitation before being centrifuged for 10 min at 13,000 rpm. Approximately 200 mL of each supernatant was then transferred to individually labeled autosampler vials. Vials were then capped and placed on the autosampler. 2.5. Instrumentation An 1100 series HPLC-DAD system (Agilent Technologies, Santa Clara, CA) with an automatic injector was used for analyses. The technique utilized was a minimally modified version of the method previously validated and published by Drummer et al. [9]. An Agilent Zorbax Eclipse XDB-C18 HPLC column (2.1 mm 150 mm, 5 mm particle size, and a matching column filter were used (Agilent Technologies). Analyses were performed using mobile phase containing phosphate buffer:acetonitrile (95:5) with a gradient elution: gradient of acetonitrile increasing to 35% at 9 min, 40% at 18 min, 45% at 20 min, 55% at 24 min, and finally returning to 5% at 27 min. 12 mL of specimens were injected at a flow rate of 0.45 mL/min. Detection of eluent was monitored at 230 nm. Total run time was 30 min with guaifenesin and MPPH eluting at 8.18 and 14.3 min, respectively. Calibrators were back calculated to original known concentrations and were within 20% of target value. A calibration curve was constructed from a minimum of the three non-zero points. The calibration used a linear regression fit (r2 0.99). Positive control samples were prepared (by an independent preparation) at concentrations of 4.0 mg/L or 10 mg/L. All specimen tubes (blood and liver homogenates) were diluted, if necessary, so the concentration would fall within the range of the calibration curve. The limit of detection and the limit of quantification, determined by the lowest calibration concentration, was 2.0 (20%) mg/L. 2.6. Accuracy and precision
2.3. Materials Guaifenesin (guaiacol glyceryl ether) was purchased from Sigma Aldrich (St. Louis, MO). The stock guaifenesin was dissolved in methanol at a concentration of 1.0 mg/mL. The internal standard used was MPPH (5-(4-methylphenyl)-5-phenylhydantoin) and this was purchased from Sigma–Aldrich (St. Louis, MO). The stock MPPH was dissolved in acetonitrile at a concentration of 1.0 mg/ mL. HPLC grade acetonitrile (Omnisolv), HPLC grade methanol (Omnisolv) and dibasic potassium phosphate (BDH) were purchased through VWR (Radnor, PA). O-Phosphoric acid, 85% was purchased from Fisher Scientific (Fair Lawn, NJ). Deionized water was obtained from a Cascada AN water purification system manufactured by Pall (Ann Arbor, MI). A 15.5 mM phosphate buffer was formulated and pH adjusted to 2.9 with O-phosphoric acid. An extraction solution consisting of acetonitrile with MPPH at a concentration of 17 mg/L was formulated. 2.4. Guaifenesin analysis Working standards were formulated by adding the appropriate amount of guaifenesin stock solution to individual volumetric flasks and diluting with deionized water to create 2.0, 5.0, 10 mg/L calibration standards. Liver specimens were homogenized by taking 5–6 g of liver specimen and blending it with an equal amount of DI water to create a 0.5 g/mL homogenate. Case specimens including blood and liver homogenates were extracted using appropriate dilutions to ensure that the quantitation fell within the linear range of the calibration curve. 0.25 mL of
Accuracy of the method for the analysis of guaifenesin in blood was established over 19 analyses (over a 6 month time-frame) and was 104% at 4 mg/L and 98% at 10 mg/L. Precision was established over the same period with guaifenesin having a coefficient of variation of 1.8% and 2.4% for concentrations of 4 mg/L and 10 mg/ L, respectively, over the same analyses. 3. Case reports 3.1. Case 1 64-Year-old male had history of daily vodka abuse and a fewdays history of fever, chills, and productive cough. He had primarily remained in bed prior to being found dead on the floor. The autopsy documented bronchopneumonia, with lung and blood cultures positive for growth of Klebsiella pneumoniae. He had marked triple-vessel coronary artery and aortic atherosclerosis, and moderate intracranial artery atherosclerotic stenosis. His liver was large and fatty. 3.2. Case 2 36-Year-old male without significant medical history who had been complaining of cold-like symptoms with upper respiratory congestion, cough, and general malaise for three days. He had been taking over-the-counter cold remedies without any significant relief. Whilst working at home on his computer, family heard him make a ‘‘hard breathing’’ noise, witnessed him become unresponsive, and
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
he was pronounced dead following resuscitative efforts. The autopsy documented no significant anatomic finding or evidence of trauma, aside from lymphocytic thyroiditis and mild inflammation of some airways. The heart’s conduction system and other major organs demonstrated no significant histopathologic finding. Amiodarone and lidocaine had been administered by emergency medical personnel. 3.3. Case 3 39-Year-old male had a history of illicit drug use and he was shot multiple times. Natural disease identified at autopsy consisted only of microscopic evidence of hepatitis.
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3.8. Case 8 73-Year-old male had history of chronic alcohol abuse and binge drinking for two weeks, having stopped 2 days prior to death. He also had history of hypertension, atrial fibrillation, atherosclerotic cardiovascular disease, and old subdural hematoma with surgical intervention. He had complained of feeling weak and having a cough, so family gave him over-the-counter cough syrup containing dextromethorphan and guaifenesin. One bottle was empty and found in his hand when he was found dead. The autopsy documented hypertensive and atherosclerotic cardiovascular disease, emphysema, and focal bronchopneumonia of one lung. The gastric contents contained a total of 100 mg guaifenesin, consistent with a recent large ingestion.
3.4. Case 4 4. Results and discussion 58-Year-old male had history of chronic pain and shoulder surgery. During the month prior to death he appeared lethargic, complained of general malaise, and thought that he had ‘‘the flu’’. Prior to being found unresponsive he was somewhat incoherent and was later pronounced dead despite resuscitative efforts. The autopsy documented endocarditis, marked coronary artery atherosclerosis, and moderate to marked aortic atherosclerosis. 3.5. Case 5 59-Year-old female had a history of hypertension, obesity, chronic neck and knee pain for which she took oxycodone, and knee replacements. She had been having cough, congestion, and nausea. She was found cold and not breathing in bed after she had been thought to be sleeping. Carisoprodol prescription was missing 28 pills in 6 days since it was prescribed (prescribed as 1 pill three times per day), one of oxycodone prescriptions was missing 88 pills in 20 days since it was prescribed (1 pill 4 times per day), and ondansetron prescription was missing 9 pills in 2 days since it was prescribed (1 pill three times per day). The autopsy documented pulmonary edema and congestion, arteriosclerotic cardiovascular disease with enlargement of the heart and focal marked coronary artery atherosclerosis; and enlargement, fatty change and mild fibrosis of the liver. 3.6. Case 6 56-Year-old female had history of bipolar disorder, borderline schizophrenia, vascular dementia, diabetes mellitus, pneumonia two years prior, breathing difficulties, and prior suicide attempt via overdose. She also had a history of intentionally and accidentally taking too much medication. On night of death she was behaving strangely, seemed ‘‘out of it,’’ and became incontinent. She later became unresponsive, ‘‘froth’’ was present in her mouth, and was later pronounced dead. The autopsy documented an obese female with acute bronchopneumonia of one of the lungs. 3.7. Case 7 66-Year-old female had history of chronic obstructive pulmonary disease, bipolar disorder, alcohol use, prescription medication overuse, remote history of ovarian cancer, treated oropharyngeal cancer, remote history of bilateral knee and hip replacements, remote history of spine fracture, and fall with humerus fracture. Prior to death, she appeared groggy but it was believed she was tired. The autopsy documented a feeding tube, an apparent subcutaneous medication pump in the chest, somewhat enlarged heart, focal moderate coronary artery atherosclerosis, acute and organizing bronchopneumonia, and centrilobular congestion and necrosis of the liver.
A total of eight cases were examined where blood [central (C) and peripheral (P)], and liver (L) were available for analysis. Guaifenesin concentrations and ratios for central to peripheral blood (C/P) and liver to peripheral blood (L/P) are shown in Table 1. Cause and manner of death and the other drugs detected in each case are shown in Table 2. Considering the ascribed causes of death––death resulting from causes other than medications/drugs––together with previous reports of toxicity, the first four cases were deemed to represent examples of non-toxic or incidental use. Using these criteria, the non-toxic postmortem peripheral blood guaifenesin concentration ranged up to 5.4 mg/L (case 1––a natural death) with a corresponding liver concentration of 2.6 mg/kg. A second nontoxic case (case 3––multiple gunshot homicide) with a peripheral blood concentration of 2.0 mg/L, exhibited a liver concentration of 7.0 mg/kg. Overall, the non-toxic concentrations ranged from 2.0 to 5.4 mg/L (peripheral blood), 2.4–5.1 mg/L (central blood), and 2.6–7.0 mg/kg (liver). Conversely, half of the cases (cases 5–8) were judged to be examples of intoxication and/or overdose in which guaifenesin was contributory––all were determined to be accidental drug deaths. The potentially toxic guaifenesin concentrations ranged from 1.9 to 40 mg/L (peripheral blood), 2.2–150 mg/L (central blood), and 8.2–36 mg/kg (liver). Clearly, guaifenesin was not found to be the cause of death in its own right––it was always combined with other medications. Cases 5 and 6 were determined to be deaths due to mixed drug toxicity, although the guaifenesin Table 1 Peripheral blood, central blood and liver guaifenesin concentrations, and ratios. Case #
P (mg/L)
C (mg/L)
L (mg/kg)
C/P ratio
L/P ratio (L/kg)
1 2 3 4
5.4 2.2 2.0 3.2
5.1 2.4 4.7 3.9
2.6 3.6 7.0 ND
0.94 1.1 2.4 1.2
0.5 1.6 3.5 –
Mean Median S.D. Range
3.2 2.7 2.4 2.0–5.4
4.0 4.3 1.2 2.4–5.1
4.4 3.6 2.4 2.6–7.0
1.4 1.1 0.72 0.94–2.4
1.9 1.6 1.3 0.5–3.5
5 6 7 8
3.9 1.9 12 40
3.9 2.2 11 150
ND ND 8.2 36
1.0 1.2 0.92 3.75
– – 0.7 0.9
Mean Median S.D. Range
14 8.0 20 1.9–40
41 7.5 83 2.2–150
22 22 20 8.2–36
1.7 1.1 1.6 0.92–3.75
0.8 0.8 0.14 0.7–0.9
P = peripheral blood; C = central blood; L = liver; ND = not detected.
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
90 Table 2 Other drugs detected, cause and manner of death. Case #
Other drugs detected
Cause of death-contributing factors
Manner of death
1
Dextromethorphan
Contents lists available at ScienceDirect
Forensic Science International journal homepage: www.elsevier.com/locate/forsciint
Postmortem distribution of guaifenesin concentrations reveals a lack of potential for redistribution Iain M. McIntyre a,*, Aylmer Navarrete a, Othon Mena b a b
Forensic Toxicology Laboratory, 5570 Overland Avenue, Suite 101, San Diego, CA 92123, USA County of San Diego Medical Examiner’s Office, 5570 Overland Avenue, Suite 101, San Diego, CA 92123, USA
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 August 2014 Received in revised form 14 October 2014 Accepted 16 October 2014 Available online 24 October 2014
Therapeutic (or non-toxic) postmortem guaifenesin blood and liver concentrations have not been previously described. Peripheral blood guaifenesin concentrations were compared to central blood and liver concentrations in eight medical examiner cases. Specimens were initially screened for alcohol and simple volatiles, drugs of abuse, alkaline, and acid/neutral drugs. Guaifenesin, when detected by the acid/ neutral drug screen, was subsequently confirmed and quantified by a high performance liquid chromatography procedure. Data suggest that postmortem guaifenesin peripheral blood concentrations may be considered non-toxic to at least 5.4 mg/L with liver concentrations to at least 7.0 mg/kg. Overall, guaifenesin concentrations ranged from 1.9 to 40 mg/L in peripheral blood, 2.2–150 mg/L in central blood, and 2.6–36 mg/kg in liver. The median guaifenesin central blood to peripheral blood ratio was 1.1 (N = 8). Similarly, liver to peripheral blood ratios showed a median value of 0.9 L/kg (N = 5). Given that a liver to peripheral blood ratio less than 5 L/kg is consistent with little to no propensity for postmortem redistribution, these data suggest that guaifenesin is not prone to substantial postmortem redistribution. Published by Elsevier Ireland Ltd.
Keywords: Guaifenesin Peripheral blood Central blood Liver Postmortem redistribution
1. Introduction Guaifenesin (Mucinex1, Robitussin1, Cheratussin1, Benylin1, DayQuil1), a guaiacol derivative, is used therapeutically as an expectorant [1,2] and a veterinary relaxant. It is also a metabolite of methocarbamol [3]. The expectorant properties of guaifenesin have endowed the drug with incorporation into numerous propriety preparations (tablet and syrups) which are commonly prescribed (together in combination with analgesics, antihistamines, antitussives or decongestants) at single doses of 50–200 mg and daily doses of up to 1200 mg, but may be used up to 2400 mg daily [1]. In clinical investigations, therapeutic plasma concentrations of guaifenesin following a dose of 200 mg (combined with 20 mg dextromethorphan) were reported to peak at 1–1.2 mg/L by 1 h [4]. Following a single oral dose of 600 mg, a mean peak blood concentration of 1.4 mg/L was attained at 15 min [5]. Guaifenesin is readily absorbed after oral administration, and it is metabolized by oxidation [2]. The estimated half-life of elimination is generally reported at about 1 h, but may increase to 5.3 h [3]. Therapeutic
* Corresponding author. Tel.: +1 858 694 2907; fax: +1 858 495 5383. E-mail address: [email protected] (I.M. McIntyre). http://dx.doi.org/10.1016/j.forsciint.2014.10.029 0379-0738/Published by Elsevier Ireland Ltd.
(or non-toxic) postmortem guaifenesin concentrations have not been described. Adverse effects of guaifenesin at higher dose levels include central nervous system depression [3]. Overdosage produces significant central nervous system (CNS) depression and guaifenesin may potentiate CNS depression when co-administered with other CNS depressants. Postmortem concentrations have been rarely described in blood or tissue. A concentration of 14 mg/L in blood (together with 3.0 mg/L hydrocodone) was reported in a single case of guaifenesin intoxication [6]. A woman died within 2 h of ingesting an overdose had a postmortem femoral blood level of 25 mg/L with an ethanol of 0.12 g/dL [7]. Another suicide involving ingestion of guaifenesin, together with diphenhydramine and chlorpheniramine, reported a postmortem heart blood guaifenesin concentration of 27 mg/L, urine 21 mg/L, bile 222 mg/ L, vitreous humor 7 mg/L, CSF 13 mg/L, and gastric contents 7700 mg [8]. Postmortem liver concentrations have not been described. To date, there has been no assessment or interpretation of the potential for guaifenesin postmortem redistribution. The study described herein examined eight postmortem cases for peripheral blood, central blood and liver concentrations from known positive guaifenesin cases. These investigations present data of postmortem distribution, and provide further insight on how liver concentrations may correlate with those of blood, and assist with
88
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
the interpretation of the drugs’ propensity for postmortem redistribution. 2. Experimental 2.1. Specimen collection and storage All specimens analyzed were collected at autopsy at the San Diego County Medical Examiner’s Office. Cases identified or suspected to be decomposed (as described in the Medical Examiner Investigation report, or at the time of autopsy) were not included. Autopsies were performed within 24–48 h after the reported time of death. Peripheral blood was drawn from the common iliac veins (blood returning from the leg and visually identified in the pelvis at autopsy) and stored in standard glass tubes containing sodium fluoride (100 mg) and potassium oxalate (20 mg). Central blood was collected from the heart or adjacent great vessels and placed in identical tubes. Sections of the upper right lobe of liver were collected and stored in a 16 ounce container without preservative. All samples were stored at 4 8C until analyzed. 2.2. Drug screening Drug screening for all cases included blood alcohol and simple volatiles by GC-FID headspace analysis, ELISA (cocaine metabolite, opiates, methamphetamine, benzodiazepines, cannabinoids, fentanyl, synthetic cannabinoids, oxycodone, methadone, zolpidem, carisoprodol, and buprenorphine) (Immunalysis Inc., CA), an alkaline drug screen by gas chromatography–mass spectrometry (GC–MS) following solid phase extraction, and an acid/neutral drug screen with high performance liquid chromatography (HPLC)photodiode array detection following specimen precipitation with acetonitrile. Guaifenesin, when detected by the acid/neutral drug screen, was subsequently confirmed and quantified by reextraction and re-analysis by a calibrated acid/neutral drug technique.
calibrators, controls and case specimens were pipetted into individual microcentrifuge tubes. 0.5 mL extraction solution (acetonitrile w/MPPH) was added to each tube and tubes were vortexed. Samples were allowed to sit at room temperature for 10 min to allow for protein precipitation before being centrifuged for 10 min at 13,000 rpm. Approximately 200 mL of each supernatant was then transferred to individually labeled autosampler vials. Vials were then capped and placed on the autosampler. 2.5. Instrumentation An 1100 series HPLC-DAD system (Agilent Technologies, Santa Clara, CA) with an automatic injector was used for analyses. The technique utilized was a minimally modified version of the method previously validated and published by Drummer et al. [9]. An Agilent Zorbax Eclipse XDB-C18 HPLC column (2.1 mm 150 mm, 5 mm particle size, and a matching column filter were used (Agilent Technologies). Analyses were performed using mobile phase containing phosphate buffer:acetonitrile (95:5) with a gradient elution: gradient of acetonitrile increasing to 35% at 9 min, 40% at 18 min, 45% at 20 min, 55% at 24 min, and finally returning to 5% at 27 min. 12 mL of specimens were injected at a flow rate of 0.45 mL/min. Detection of eluent was monitored at 230 nm. Total run time was 30 min with guaifenesin and MPPH eluting at 8.18 and 14.3 min, respectively. Calibrators were back calculated to original known concentrations and were within 20% of target value. A calibration curve was constructed from a minimum of the three non-zero points. The calibration used a linear regression fit (r2 0.99). Positive control samples were prepared (by an independent preparation) at concentrations of 4.0 mg/L or 10 mg/L. All specimen tubes (blood and liver homogenates) were diluted, if necessary, so the concentration would fall within the range of the calibration curve. The limit of detection and the limit of quantification, determined by the lowest calibration concentration, was 2.0 (20%) mg/L. 2.6. Accuracy and precision
2.3. Materials Guaifenesin (guaiacol glyceryl ether) was purchased from Sigma Aldrich (St. Louis, MO). The stock guaifenesin was dissolved in methanol at a concentration of 1.0 mg/mL. The internal standard used was MPPH (5-(4-methylphenyl)-5-phenylhydantoin) and this was purchased from Sigma–Aldrich (St. Louis, MO). The stock MPPH was dissolved in acetonitrile at a concentration of 1.0 mg/ mL. HPLC grade acetonitrile (Omnisolv), HPLC grade methanol (Omnisolv) and dibasic potassium phosphate (BDH) were purchased through VWR (Radnor, PA). O-Phosphoric acid, 85% was purchased from Fisher Scientific (Fair Lawn, NJ). Deionized water was obtained from a Cascada AN water purification system manufactured by Pall (Ann Arbor, MI). A 15.5 mM phosphate buffer was formulated and pH adjusted to 2.9 with O-phosphoric acid. An extraction solution consisting of acetonitrile with MPPH at a concentration of 17 mg/L was formulated. 2.4. Guaifenesin analysis Working standards were formulated by adding the appropriate amount of guaifenesin stock solution to individual volumetric flasks and diluting with deionized water to create 2.0, 5.0, 10 mg/L calibration standards. Liver specimens were homogenized by taking 5–6 g of liver specimen and blending it with an equal amount of DI water to create a 0.5 g/mL homogenate. Case specimens including blood and liver homogenates were extracted using appropriate dilutions to ensure that the quantitation fell within the linear range of the calibration curve. 0.25 mL of
Accuracy of the method for the analysis of guaifenesin in blood was established over 19 analyses (over a 6 month time-frame) and was 104% at 4 mg/L and 98% at 10 mg/L. Precision was established over the same period with guaifenesin having a coefficient of variation of 1.8% and 2.4% for concentrations of 4 mg/L and 10 mg/ L, respectively, over the same analyses. 3. Case reports 3.1. Case 1 64-Year-old male had history of daily vodka abuse and a fewdays history of fever, chills, and productive cough. He had primarily remained in bed prior to being found dead on the floor. The autopsy documented bronchopneumonia, with lung and blood cultures positive for growth of Klebsiella pneumoniae. He had marked triple-vessel coronary artery and aortic atherosclerosis, and moderate intracranial artery atherosclerotic stenosis. His liver was large and fatty. 3.2. Case 2 36-Year-old male without significant medical history who had been complaining of cold-like symptoms with upper respiratory congestion, cough, and general malaise for three days. He had been taking over-the-counter cold remedies without any significant relief. Whilst working at home on his computer, family heard him make a ‘‘hard breathing’’ noise, witnessed him become unresponsive, and
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
he was pronounced dead following resuscitative efforts. The autopsy documented no significant anatomic finding or evidence of trauma, aside from lymphocytic thyroiditis and mild inflammation of some airways. The heart’s conduction system and other major organs demonstrated no significant histopathologic finding. Amiodarone and lidocaine had been administered by emergency medical personnel. 3.3. Case 3 39-Year-old male had a history of illicit drug use and he was shot multiple times. Natural disease identified at autopsy consisted only of microscopic evidence of hepatitis.
89
3.8. Case 8 73-Year-old male had history of chronic alcohol abuse and binge drinking for two weeks, having stopped 2 days prior to death. He also had history of hypertension, atrial fibrillation, atherosclerotic cardiovascular disease, and old subdural hematoma with surgical intervention. He had complained of feeling weak and having a cough, so family gave him over-the-counter cough syrup containing dextromethorphan and guaifenesin. One bottle was empty and found in his hand when he was found dead. The autopsy documented hypertensive and atherosclerotic cardiovascular disease, emphysema, and focal bronchopneumonia of one lung. The gastric contents contained a total of 100 mg guaifenesin, consistent with a recent large ingestion.
3.4. Case 4 4. Results and discussion 58-Year-old male had history of chronic pain and shoulder surgery. During the month prior to death he appeared lethargic, complained of general malaise, and thought that he had ‘‘the flu’’. Prior to being found unresponsive he was somewhat incoherent and was later pronounced dead despite resuscitative efforts. The autopsy documented endocarditis, marked coronary artery atherosclerosis, and moderate to marked aortic atherosclerosis. 3.5. Case 5 59-Year-old female had a history of hypertension, obesity, chronic neck and knee pain for which she took oxycodone, and knee replacements. She had been having cough, congestion, and nausea. She was found cold and not breathing in bed after she had been thought to be sleeping. Carisoprodol prescription was missing 28 pills in 6 days since it was prescribed (prescribed as 1 pill three times per day), one of oxycodone prescriptions was missing 88 pills in 20 days since it was prescribed (1 pill 4 times per day), and ondansetron prescription was missing 9 pills in 2 days since it was prescribed (1 pill three times per day). The autopsy documented pulmonary edema and congestion, arteriosclerotic cardiovascular disease with enlargement of the heart and focal marked coronary artery atherosclerosis; and enlargement, fatty change and mild fibrosis of the liver. 3.6. Case 6 56-Year-old female had history of bipolar disorder, borderline schizophrenia, vascular dementia, diabetes mellitus, pneumonia two years prior, breathing difficulties, and prior suicide attempt via overdose. She also had a history of intentionally and accidentally taking too much medication. On night of death she was behaving strangely, seemed ‘‘out of it,’’ and became incontinent. She later became unresponsive, ‘‘froth’’ was present in her mouth, and was later pronounced dead. The autopsy documented an obese female with acute bronchopneumonia of one of the lungs. 3.7. Case 7 66-Year-old female had history of chronic obstructive pulmonary disease, bipolar disorder, alcohol use, prescription medication overuse, remote history of ovarian cancer, treated oropharyngeal cancer, remote history of bilateral knee and hip replacements, remote history of spine fracture, and fall with humerus fracture. Prior to death, she appeared groggy but it was believed she was tired. The autopsy documented a feeding tube, an apparent subcutaneous medication pump in the chest, somewhat enlarged heart, focal moderate coronary artery atherosclerosis, acute and organizing bronchopneumonia, and centrilobular congestion and necrosis of the liver.
A total of eight cases were examined where blood [central (C) and peripheral (P)], and liver (L) were available for analysis. Guaifenesin concentrations and ratios for central to peripheral blood (C/P) and liver to peripheral blood (L/P) are shown in Table 1. Cause and manner of death and the other drugs detected in each case are shown in Table 2. Considering the ascribed causes of death––death resulting from causes other than medications/drugs––together with previous reports of toxicity, the first four cases were deemed to represent examples of non-toxic or incidental use. Using these criteria, the non-toxic postmortem peripheral blood guaifenesin concentration ranged up to 5.4 mg/L (case 1––a natural death) with a corresponding liver concentration of 2.6 mg/kg. A second nontoxic case (case 3––multiple gunshot homicide) with a peripheral blood concentration of 2.0 mg/L, exhibited a liver concentration of 7.0 mg/kg. Overall, the non-toxic concentrations ranged from 2.0 to 5.4 mg/L (peripheral blood), 2.4–5.1 mg/L (central blood), and 2.6–7.0 mg/kg (liver). Conversely, half of the cases (cases 5–8) were judged to be examples of intoxication and/or overdose in which guaifenesin was contributory––all were determined to be accidental drug deaths. The potentially toxic guaifenesin concentrations ranged from 1.9 to 40 mg/L (peripheral blood), 2.2–150 mg/L (central blood), and 8.2–36 mg/kg (liver). Clearly, guaifenesin was not found to be the cause of death in its own right––it was always combined with other medications. Cases 5 and 6 were determined to be deaths due to mixed drug toxicity, although the guaifenesin Table 1 Peripheral blood, central blood and liver guaifenesin concentrations, and ratios. Case #
P (mg/L)
C (mg/L)
L (mg/kg)
C/P ratio
L/P ratio (L/kg)
1 2 3 4
5.4 2.2 2.0 3.2
5.1 2.4 4.7 3.9
2.6 3.6 7.0 ND
0.94 1.1 2.4 1.2
0.5 1.6 3.5 –
Mean Median S.D. Range
3.2 2.7 2.4 2.0–5.4
4.0 4.3 1.2 2.4–5.1
4.4 3.6 2.4 2.6–7.0
1.4 1.1 0.72 0.94–2.4
1.9 1.6 1.3 0.5–3.5
5 6 7 8
3.9 1.9 12 40
3.9 2.2 11 150
ND ND 8.2 36
1.0 1.2 0.92 3.75
– – 0.7 0.9
Mean Median S.D. Range
14 8.0 20 1.9–40
41 7.5 83 2.2–150
22 22 20 8.2–36
1.7 1.1 1.6 0.92–3.75
0.8 0.8 0.14 0.7–0.9
P = peripheral blood; C = central blood; L = liver; ND = not detected.
I.M. McIntyre et al. / Forensic Science International 245 (2014) 87–91
90 Table 2 Other drugs detected, cause and manner of death. Case #
Other drugs detected
Cause of death-contributing factors
Manner of death
1
Dextromethorphan
