Toxicology and alcohol
Pharmacology is the study of the use of drugs to
improve the functioning of the body of a living being. Toxicology is the study
of the chemical and physical characteristics of toxic substances (drugs and
poisons) and the physiological effects on the human body. This also includes
the analytical methods to determine the level of the substance in the body, as
well as the treatment of poisoning or overdosing.
Put simply, pharmacology refers to those cases
where a drug is beneficial for an individual, and may even cure the individual.
However, if a drug is consumed in too high a dosage, it has toxic effects, and
that is toxicology. This can be an over-simplification, but even Paracelsus
(1493±1541) remarked: ``All drugs are poisons; there is not one
which is not a poison. The right dose differentiates a poison from a remedy''.
Toxicology and poisoning have formed part of
human life since the beginning of time. Diseases which are today treatable with
medication with relatively few if any side effects, were until not so long ago
treated with drugs or substances which few, if any, modern men will dare to
ingest. The treatment of syphilis, for instance, was with arsenic salts.
Mercury was used for other ailments.
The following inscription was found on a tomb in
the Cross Kirk cemetery in Eshaness, Shetland:
Born 11th January, 1785, Died 4th June, 1848,
aged 63 years.
He was a peaceable quiet man and to all
appearances a sincere Christian. His death was
very much regretted, which was caused by the
stupidity of Laurence Tulloch in Clothester,
who sold him nitre instead of Epsom salts,
by which he was killed in the space of 3 hours
after taking a dose of it.
If Donald Robertson did take the customary
teaspoonful of what he thought to be Epsom salts, he probably ingested about 5
g or more of nitre (saltpetre). Severe abdominal pain, vomiting and diarrhoea
probably commenced shortly thereafter, leading to a state of shock, and death.
Post-mortem lividity was probably of a chocolate-brown colour due to the
formation of methaemo-globin. Saltpetre was and still is in use as a meat preservative
and colourant, and in small doses may give rise to reactions of
hypersensitivity. One wonders what the court would have awarded as damages in
Prescribing drugs is not without risk, even in
modern times. The doctor's illegible handwriting, an incorrect unit, for
instance gram instead of milligram or an incorrect dose interval are but a few
examples that can lead to misinterpretation. In addition the pharmacist and the
patient can also play a role. The elderly are especially at risk when it comes
to taking medicines. Often their memories are not good any longer, and they
forget whether they already took their daily medication or not. Diabetics
sometimes have bad eyesight and cannot see exactly how much insulin they are
administering to themselves.
In this study unit a few general principles of
pharmacology and toxicology will be discussed, and two important substances
(carbon monoxide and alcohol) will be discussed in more detail.