Antabuse

Drug Uses

For social and historical reasons we normally buy alcohol in a bar instead of man. Pharmacy because it is considered to be a drink and not a drug, but pharmacologically speaking it has much in common with medicinal drugs which depress the central nervous system. Objective tests show that as blood-alcohol levels rise, the ability to perform a number of skills gradually deteriorates because of the progessive disorganization of the brain. The myth that alcohol is a stimulant has arisen because at parties and social occasions it helps people to lose some of their inhibitions and allows them to relax and unwind. Professor JH Gaddum put it amusingly and succinctly when, describing the early effects of moderate amounts of alcohol, he wrote that logical thought is difficult but after dinner speeches easy. The expansiveness and locquaciousness which are socially acceptable lead on, with increasing amounts of alcohol, to unrestrained behaviour in normally well-controlled individuals, through drunkeness, unconsciousness and finally death from respiratory failure. These effects are all a reflection of the progressive and deepening depression of the CNS Since alcohol impairs the skills needed to drive a car safely, almost all national and state authorities have imposed maximum legal blood-alcohol limits. In the UK and a number of other countries this is currently 80 mg, but impairment is clearly detectable at lower concentrations and because of this some countries have imposed much lower legal limits.

Table 2 1 gives an indication m very broad terms of the reactions of men and women to different amounts and concentrations of alcohol. On the whole women are smaller than men and their body fluids also represent a smaller proportion of then total body mass, so that after taking the same drink the blood-alcohol level of a woman is likely to be higher than that of a man. The values given assume that the drinkers regularly drink, have had a meal and weigh between 9 and 11 stones (55-70 kg). Higher blood alcohol levels would occur if drunk on an empty stomach and lower values m much heavier individuals. The liver metabolizes about one unit per hour so that the values will fall with time.

Probably the most common drug interaction of all occurs if alcohol is drunk while taking other drugs which have CNS depressant activity. This can occur with some antihistamines, analgesics, antidepressants, hypno-sedatives, tranquillizers, travel-sickness remedies and others (see Alcohol & CNS depressants). This chapter contains a number of synopses which describe the results of formal studies on recognized CNS depressants (see the index), but there are large numbers of other drugs which still await study of this kind and which undoubtedly represent a real hazard.

A less serious but not uncommon interaction between alcohol and some other drugs and chemical agents is the flushing (Antabuse) reaction which is exploited m the case of disulfiram.