Drug repurposing is big business. Investigating the further potential of existing drugs saves the time – at least a decade – and money – around a billion pounds – required to get a new drug from the drawing board to the prescription pad.
Thirty years ago, in early clinical trials sildenafil wasn’t doing much for angina. But men who took it had penile erections. So started the medical, economic and social history of Viagra, probably the most famous repurposed drug in the history of pharmacology. Since when, it has been further repurposed with less publicity for treating pulmonary hypertension, and is being trialled for high-altitude pulmonary oedema and Raynaud’s.
Few other repurposed drugs enter popular culture, though minoxidil, developed for treating cardiovascular problems, has been sufficiently effective for hair growth to reappear as Regaine on the London Underground.
