Mecillinam, a new prophylactic for travellers' diarrhoea. A prospective double-blind study in tourists travelling to Egypt and the Far East.

The efficacy of mecillinam when given orally in preventing travellers' diarrhoea has been studied. Preliminary investigations in volunteers showed that single daily doses of up to 200 mg for 3 weeks were well tolerated. A randomised double-blind study was carried out in a group of tourists visiting Egypt and the Far East. The subjects took either mecillinam (200 mg daily) or placebo for 25 days. 19/36 tourists (53%) taking placebo and 5/38 tourists (13%) taking mecillinam developed travellers' diarrhoea during the treatment period (p less than 0.001). In the placebo group enterotoxigenic Escherichia coli (LT/ST) were found in 2 cases of diarrhoea and Salmonella in another 2 cases. In the remaining cases of diarrhoea the etiological agent was not found in either of the 2 groups.