Forensic Issues (Anti-infectives)
■■ Poisoning resulting
from pharmaceutical preparations is usually accidental in nature arising out of
therapeutic overdose, allergic reactions, or inadvertent ingestion (mistaken
identity, paediatric poisoning, etc.). The usual culprits include analgesic-antipyretics,
NSAIDs, benzodiazepines, sedative-hypnotics, antidepressants, and
from anti-infective drugs is relatively uncommon, though adverse (side) effects
especially at high therapeutic doses frequently occur, which is all the more
likely if the duration of therapy is prolonged. However as the incidence of
poisoning relentlessly rises in India, the agents employed for deliberate
self-ingestion have undergone a subtle but definite change over a period of
time. While chemicals and plant products were overwhelmingly common in the
past, today pharmaceutical preparations are making significant inroads.
though this may be true, the contribution of anti-infective drugs to this grim
scenario still remains negligible as demonstrated by studies in which
therapeutic drugs accounted for upto 20 to 30 % of suicidal poisoning, andyet
anti-infective preparations hardly figured in the list of culprits. That is of
course no reason to be complacent since these drugs are so frequently
prescribed, and there-fore the incidence of accidental overdose is probably not
insignificant inspite of a paucity of studies substantiating this assumption.
■■ In Western countries with advanced
economies and rela-tively sophisticated medical services, suicidal poisoning
with pharmaceutical preparations has always been more common than toxic agents.
This is due to easy acces-sibility, since these drugs are either obtainable
from a doctor on prescription, or on demand across the counter of a pharmacy.
■■ In the Indian context, the
following examples represent some common situations producing anti-infective
drug morbidity and mortality:
o Idiosyncratic reactions to drugs,
e.g. quinine. Allergic reactions including anaphylaxis, e.g. penicil-lins.
o G6PD deficiency in some individuals
which can predis-pose to toxicity even with therapeutic doses of some drugs,
e.g. primaquine, dapsone.
o Inadvertent intake of alcohol along
with incompatible anti-infectives, e.g. metronidazole, cephalosporines,
griseofulvin, etc. However, well controlled studies have not substantiated this
disulfiram-like reaction with regard to metronidazole and alcohol. The
likelihood of this drug interaction is not considered clinically significant,
since in some studies it has occurred with placebo. Several reports have
anecdotally described deliberate abuse of the metronidazole-alcohol
combi-nation to produce pleasurable CNS effects: a sudden onset or “rush” of
excitement, giddiness, and flushing. Nausea was denied or reported as a
transient effect by these subjects.
o Tetracycline ingestion (usually on
the advice of quacks) by children and pregnant women, resulting in dental and
o Ignorant patients ingesting outdated
anti-infectives (especially tetracycline) which can cause renal prob-lems.
o Administration of chloramphenicol to
neonates by quacks.
o Accidental paediatric poisoning
involving attractively coloured or flavoured medicines.
o Use of quinine as abortifacient in
rural areas. Chronic toxicity resulting from inadequately supervised treatment
regimens involving the use of drugs such as INH,*
dapsone, chloroquine, aminoglycosides, penicil-lins, macrolides, and