Forensic Pathology for Police - Brainshare Public Online Library

Death Certification 267
blood via diffusion from adjacent structures (stomach, liver). It is generally agreed
that the best blood sample to collect in order to minimize the effects of postmortem
redistribution is femoral blood. Examples of drugs that are known to exhibit marked
postmortem redistribution include tricyclic antidepressants and propoxyphene. In
cases where postmortem redistribution has occurred, heart blood samples have drug
levels that are much higher than femoral blood samples.
Another issue of concern is the concept of “pharmacogenomics.” Different people
have genetic variations in the enzymes used to metabolize certain drugs. As
such, a given dose of a particular drug may cause certain, predictable results in many
individuals, but have serious or even lethal effects in another individual. For example,
many persons of Chinese, Vietnamese, and Japanese descent have a reduced
activity of one of the enzymes involved in the metabolism of ethanol (drinking alcohol).
When these individuals drink alcohol, they have a severe reaction with facial
flushing.
For some drugs, a generally accepted level for lethality is known. In other words,
a death will not be considered due to the toxic effects of that drug unless the blood
level is at or above the generally accepted lethal level. For other drugs, such a level
does not exist, or the levels in cases reportedly due to the drug are so widely spread
that a generally accepted lethal level is not agreed upon. Many factors contribute
to this somewhat confusing situation regarding these drugs, including postmortem
redistribution, postmortem metabolism, pharmacogenomics, short half-lives, tolerance,
and the fact that with many such drugs a possible mechanism of death involves
the initiation of a lethal cardiac arrhythmia or perhaps a seizure. With drugs that can
induce a lethal arrhythmia or seizure, it can be argued that, in a given individual,
an absolutely safe level of the drug may not exist. It is beyond the scope of this
text to provide detailed information regarding lethal levels of the drugs and toxins
discussed. The reader is referred to an excellent reference book, Disposition of
Toxic Drugs and Chemicals in Man, eighth edition, by Randall C. Baselt (copyright
2008 by Biomedical Publications, Foster City, CA), as an extremely useful resource
regarding lethal drug levels.
Death Certification
If a death is caused exclusively by the acute toxic effects of a drug, the cause of
death ruling can be written in several different ways. Examples include “toxic effects
of cocaine,” “cocaine intoxication,” or “acute cocaine intoxication.” If more than
one drug is involved, several options exist, for example, “mixed drug intoxication,”
“combined toxic effects of multiple drugs,” or “combined intoxication with cocaine
and heroin.” Occasionally, an underlying natural disease process or finding may
be considered contributory to death. It is appropriate to list such a finding in part
II of the death certificate. For example, part I – toxic effects of cocaine; part II –
cardiomegaly. In other instances, a natural disease process may be considered the
primary cause of death, but the presence of a drug intoxication is believed to have