Nikethamide is a respiratory and circulatory stimulant with some central nervous system activity. Widely known by its former trade name of Coramine, it was used in the mid-twentieth century as a medical countermeasure against tranquilizer overdoses, before the advent of endotracheal intubation and positive-pressure lung expansion. Nikethamide is available as a short-acting over-the-counter drug in several South American and European countries, combined with glucose in form of lozenges. Nikethamide is especially useful for mountain climbers to increase endurance at high altitudes. Contraindications include hypertension, cardiovascular pathologies, and epilepsy. In some sports, nikethamide is listed by the World Anti-Doping Agency as a banned substance. Croatian tennis player Marin Čilić was suspended from competition for nine months after he tested positive for nikethamide in April 2013