Journal of Forensic and Legal Medicine 25 (2014) 77e84
Contents lists available at ScienceDirect
Journal of Forensic and Legal Medicine j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / j fl m
Original communication
Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: The effect of short-term variation David W. Sadler*, James Parker a Centre for Forensic and Legal Medicine, University of Dundee, Dundee DD1 4HN, UK
a r t i c l e i n f o
a b s t r a c t
Article history: Received 24 January 2014 Received in revised form 12 April 2014 Accepted 21 April 2014 Available online 4 May 2014
Ten male and 8 female students underwent serial breath alcohol concentration (BrAC) measurements on a CAMIC Datamaster on two consecutive occasions, early evening and again the following morning. Subjects were fasted for 6 h before receiving alcohol as white wine (12.5% by volume) at doses of 38e45 g for males and 26e37 g for females, consumed over 10 min. Specific individual doses were calculated individually from height and weight (according to the Forrest Method) to give target C0 breath alcohol concentrations of 35 mg/100 ml breath in males and 31 mg/100 ml breath in females. BrAC versus time curves were constructed for each subject and the values of peak BrAC (Cmax), BrAC extrapolated at zero time (C0), time taken to reach peak (Tmax) and rate of elimination (ß) were recorded directly from the curves. Values of C0 taken from the BrACetime curves varied widely, from 21 to 47 mg/ 100 ml on visit 1 and from 22 to 45 mg/100 ml on visit 2. Widmark Factors calculated from these C0 values averaged 0.74 (range, 0.59e1.06) in males and 0.73 (range, 0.58e1.05) in females. Elimination rate was higher in the morning than evening in both males (7.4 versus 5.7 mg/100 ml/h) and females (6.9 versus 5.8 mg/100 ml/h). Elimination rates in males and females were not significantly different. Total body water, measured by electronic scales, averaged 58.7% (range, 56.6e63%) in males and 48.3% (range, 40.9 e57.6%) in females. Widmark Factors calculated by various established mathematical methods were 0.73 e0.77 in males and 0.61e0.64 in females. Ó 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Keywords: Breath Alcohol Concentration Pharmacokinetics Variation Total body water
1. Introduction Measurement of alcohol concentration in blood and breath is of major medico-legal importance with respect to drink-driving offences. Many of the more recent studies have involved measurement of breath alcohol concentration (BrAC) since this is the primary evidential specimen in most jurisdictions, its measurement is less invasive than blood sampling and because BrAC is thought to correlate well with blood alcohol concentration (BAC).1 Breath samples have been found to show similar or lower variations than blood, both within and between subjects.2 Numerous factors may affect the rate and extent of alcohol absorption and its rate of elimination. Alcohol absorption rate is dependent upon the concentration of alcohol in the beverage consumed and upon carbonation of any mixers used.3 Taking food
* Corresponding author. Tel.: þ44 (0) 1382 596544. E-mail address: [email protected] (D.W. Sadler). a Tel.: þ44 (0) 1382 596544.
with alcohol is known to both reduce the peak blood alcohol level achieved and enhance the rate of alcohol elimination.4e7 Conversely, other studies demonstrated a slightly lower rate of alcohol elimination from breath after food.8e10 The peak level achieved after food may only reach
Contents lists available at ScienceDirect
Journal of Forensic and Legal Medicine j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / j fl m
Original communication
Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: The effect of short-term variation David W. Sadler*, James Parker a Centre for Forensic and Legal Medicine, University of Dundee, Dundee DD1 4HN, UK
a r t i c l e i n f o
a b s t r a c t
Article history: Received 24 January 2014 Received in revised form 12 April 2014 Accepted 21 April 2014 Available online 4 May 2014
Ten male and 8 female students underwent serial breath alcohol concentration (BrAC) measurements on a CAMIC Datamaster on two consecutive occasions, early evening and again the following morning. Subjects were fasted for 6 h before receiving alcohol as white wine (12.5% by volume) at doses of 38e45 g for males and 26e37 g for females, consumed over 10 min. Specific individual doses were calculated individually from height and weight (according to the Forrest Method) to give target C0 breath alcohol concentrations of 35 mg/100 ml breath in males and 31 mg/100 ml breath in females. BrAC versus time curves were constructed for each subject and the values of peak BrAC (Cmax), BrAC extrapolated at zero time (C0), time taken to reach peak (Tmax) and rate of elimination (ß) were recorded directly from the curves. Values of C0 taken from the BrACetime curves varied widely, from 21 to 47 mg/ 100 ml on visit 1 and from 22 to 45 mg/100 ml on visit 2. Widmark Factors calculated from these C0 values averaged 0.74 (range, 0.59e1.06) in males and 0.73 (range, 0.58e1.05) in females. Elimination rate was higher in the morning than evening in both males (7.4 versus 5.7 mg/100 ml/h) and females (6.9 versus 5.8 mg/100 ml/h). Elimination rates in males and females were not significantly different. Total body water, measured by electronic scales, averaged 58.7% (range, 56.6e63%) in males and 48.3% (range, 40.9 e57.6%) in females. Widmark Factors calculated by various established mathematical methods were 0.73 e0.77 in males and 0.61e0.64 in females. Ó 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Keywords: Breath Alcohol Concentration Pharmacokinetics Variation Total body water
1. Introduction Measurement of alcohol concentration in blood and breath is of major medico-legal importance with respect to drink-driving offences. Many of the more recent studies have involved measurement of breath alcohol concentration (BrAC) since this is the primary evidential specimen in most jurisdictions, its measurement is less invasive than blood sampling and because BrAC is thought to correlate well with blood alcohol concentration (BAC).1 Breath samples have been found to show similar or lower variations than blood, both within and between subjects.2 Numerous factors may affect the rate and extent of alcohol absorption and its rate of elimination. Alcohol absorption rate is dependent upon the concentration of alcohol in the beverage consumed and upon carbonation of any mixers used.3 Taking food
* Corresponding author. Tel.: þ44 (0) 1382 596544. E-mail address: [email protected] (D.W. Sadler). a Tel.: þ44 (0) 1382 596544.
with alcohol is known to both reduce the peak blood alcohol level achieved and enhance the rate of alcohol elimination.4e7 Conversely, other studies demonstrated a slightly lower rate of alcohol elimination from breath after food.8e10 The peak level achieved after food may only reach
