The Poison Chronicles: Deadly Doping with Strychnos nux-vomica

Posted on January 10, 2017 Updated on January 9, 2017

Guest post by Laura Cooper

Strychnine is an infamous poison. It is most well-known by its appearance in the novels of Agatha Christie as an effective but unsubtle method of murder. It was widely available in the 19^th century from chemists as a rat poison, but this was taken advantage of by a number of real life serial killers including Dr Thomas Cream who gave disguised as a medicine and in alcohol. But strychnine had another side to it. Its caffeine- like stimulating effects means it has been used as a performance enhancing drug in competitive sports.

Strychnine, along with the toxin brucine, is present in the seeds of Strychnos nux-vomica. Though its name is lurid, it does not have anything to do with vomiting, “nux vomica” translates as ‘bumpy nut’. S. nux-vomica is in the family Loganiaceae and is native to South-East Asia and India. It is a medium-sized tree with large smooth oval leaves. The flowers have a repellent smell and the fruit is apple-sized with a hard shell that is orange when ripe. Inside, the seed are held in soft gelatinous pulp. The seeds are flattened disks covered with fine hairs, their flatness gives them the nickname ‘Quaker buttons’. The strychnine is concentrated in the seeds, but the wood also possesses poisons including brucine. Strychnine in the S. nux- vomica plays the same role as abrin in Abrus precatorius, it prevents herbivore species evolving which specialize in eating these seeds, as the poison is so general that it will likely kill any animal that eats the seed.

Strychnine poisons by blocking glycine from binding to specific neurons in the central nervous system. Strychnine prevents glycine from carrying out its inhibitory role, so causes the central nervous system to over-react to the smallest stimulus.

Initially the muscles become stiff, which is followed by hyperreflexia, where small stimulus trigger powerful reflex reactions. Later, increasingly frequent whole body convulsions occur. These resemble those in tetanus, an explanation often used to cover up strychnine poisoning. Eventually the respiratory muscles become paralysed and death by asphyxiation  occurs usually within a few hours. Strychnine cannot cross the blood-brain barrier, so the victim is fully conscious throughout, making strychnine poisoning one of the worst ways to die I can imagine.

The main method of treating strychnine poisoning is crude. The patient is given barbiturates and muscle relaxants and removed from stimuli to prevent convulsions until the strychnine is metabolised by the liver which takes a few days.

However, S. nux-vomica extracts have been used in herbal and alternative medicine. It has been recommended for many different health issues from abdominal pain, heart disease and migraines though there is no evidence for its efficacy as a drug. However, a low dose of strychnine stimulates the central nervous system in a similar way to caffeine, but to a greater extent. This gives it great potential to act as a placebo, which is likely why it was reported to treat a wide range of illnesses, as well as to help spur athletes to victory.

S. nux-vomica‘s stimulating effects were used in 19^th and early 20^th century Europe and America in competitive sports as one of an arsenal of performance enhancing drugs, which were even deemed necessary for some endurance sports. Strychnine helped the American Thomas Hicks secure an Olympic Gold Medal. He was given strychnine and brandy during the 1904 Olympic marathon when he was flagging, though he collapsed after crossing the finishing line he later recovered. To this day, strychnine is on the list of banned stimulants in the World Anti-Doping Agency International Standard Prohibited List.

For more information, see the Poison Garden’s page on the species and Ian Musgrave’s article on strychnine in sport.