Drug concentration in selected skeletal muscles

Area of Science:

• Forensic Toxicology
• Pharmacokinetics
• Analytical Chemistry

Background:

• Accurate drug concentration measurement is crucial in forensic toxicology and clinical settings.
• Muscle tissue is a potential biological matrix for drug analysis, but its homogeneity is not well-established.
• Understanding drug distribution in muscle is key to interpreting post-mortem and therapeutic drug levels.

Purpose of the Study:

• To evaluate the homogeneity and reliability of drug concentrations in various human skeletal muscles.
• To compare muscle drug concentrations with femoral venous blood concentrations.
• To determine the suitability of muscle tissue for quantitative drug analysis.

Main Methods:

• Analysis of drug concentrations in twelve named muscles and femoral venous blood from 14 cadavers.
• Inclusion of cases involving drug overdoses and chronic therapeutic drug use.
• Utilization of standard analytical techniques and instrumentation for drug quantification.

Main Results:

• Marked within-case variability in muscle drug concentrations was observed, with highest:lowest ratios up to 21.7.
• The diaphragm exhibited the highest overall drug concentrations, with diaphragm:blood ratios varying significantly by drug.
• Excluding the diaphragm, mean muscle:blood ratios also showed considerable variation, indicating non-uniform drug distribution.

Conclusions:

• Muscle tissue demonstrates significant heterogeneity in drug concentrations, limiting its quantitative utility.
• Muscle is suitable for qualitative drug detection but not for quantitative corroboration or as an alternative to blood analysis.
• Results suggest that blood remains the preferred matrix for quantitative drug concentration measurements in forensic and clinical toxicology.