Handbook of Drug Interactions

210 Welner
causing seizures (114), which can create a highway catastrophe. In this regard, standard
psychiatric practice has reinforced the responsibility for psychiatrists to advise patients
of risks associated with operating such items when prescribed antipsychotics.
9. COMPETENCY TO INVEST, TESTAMENTARY CAPACITY
Legal questions, often posthumous, arise over decisions to invest or to earmark
assets. Since trusts and wills often concern individuals with health problems, such decisions
may be affected by the interactions of prescribed drugs. Cases involving such
competencies therefore warrant close scrutiny of medical, prescription, and pharmacy
records. Comparison of decisions made, with corresponding dates, yields vital detail
about the relevance of drug interactions.
As agitation in the medically ill, and in the elderly, is often treated with antipsychotics,
confusion and sedation may be attributable to the medicine—if not the underlying
condition. Careful consideration of the clinical course will enable the distinction
of whether a drug interaction was responsible.
The elderly, and those incapacitated who are making financial decisions, are
particularly vulnerable to undue influence. Loving relatives with self-serving motives
can position themselves opportunistically. For this reason, sedation, heightened by drug
interactions, should also be tracked. If undue influence is suspected, and the agent had
continuous proximity to an ill but wealthy patient, the deceased’s blood should be tested
to ensure that no medicines were administered, in combination, that would have perpetuated
mental incapacity or hastened death.
The study of drug interactions is ongoing. New discoveries from clinical use of
combinations of an ever-growing pharmacopoeia add to our appreciation of interactions.
These findings will one day provide answers to some of the peculiar forensic scenarios
that we now suspect are influenced by drug interactions, but cannot yet explain.
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