ABSTRACT
These substances are discussed solely from the point of view of the pathologist dealing with fatal cases.
Drugs of dependence may be absorbed orally, by intravenous, subcutaneous or – rarely – intramuscular injection, by smoking, or by nasal sniffing. The routine at autopsy, in respect of obtaining samples for toxicological analysis, is altered according to the route of administration. As mixing of drugs and addition of non-narcotic drugs is common, it is the usual practice to take a wide range of samples even if the primary route is known with some degree of certainty. For example, an addict dying ‘on the needle’ where intravenous injection is obvious, will still have stomach contents taken for investigation. The standard samples should be taken, as described in a previous chapter, comprising several samples of venous blood (one with fluoride), stomach and contents, liver and urine. In some circumstances, additional samples such as bile, cerebrospinal fluid and vitreous humour may be taken, as well as brain or kidney. The great advances in the analytical techniques allow the analysis of drugs also in other biological samples, such as saliva, sweat and hair. Hair analysis can also provide evidence of long-term exposure to drugs (weeks, months or years), because most drugs, if not all, incorporate in hair and are relatively stable. At least 50 mg of hair should be collected, cutting about a pencil thickness of strands of hair as close to the skin as possible from the back of the head, dried and stored in a sealed plastic bag or tube at room temperature.
