The former musician, of Willen, Milton Keynes, pressed the plunger himself to inject the barbiturates that ended his life.

BBC: 'My brother chose to end his suffering'

Sodium pentothal, the trade name for thiopental, is the best-known of a class of barbiturates popularly supposed to act as truth serums.

ECONOMIST: Drugs cannot make you tell the truth

Simple, and safe: for the problem with all tranquillisers up till then, from henbane and absinthe to barbiturates, was that they gave unpleasant side effects at moderate doses and, at larger ones, killed you.

ECONOMIST: Leo Sternbach

Dr David Gunnell and colleagues from Bristol University point out that the method of suicide favoured by women - drug overdose - has become less lethal owing to the replacement of barbiturates by the less toxic benzodiazepines in the 1980s.

BBC: 20.50 11-02-99 pills ac

Although I don't administer these barbiturates.

NPR: The Medical Ethics of the Death Penalty