Toxicology and alcohol

Toxicology and alcohol

Introduction

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:

Donald Robertson

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 those times.

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.