Canesten Thrush Oral Capsule Canesten Thrush Oral Capsule is a single dose, full course treatment for vaginal thrush, for women who have been previously diagnosed by their doctor as having thrush & who haven't had it more than twice in the previous six months. It can also be used by a male partner if he has thrush on his penis. Thrush is caused by a yeast (fungus) called Candida which lives harmlessly in the vagina & other parts of the body, without you even noticing it. However, if the natural p H balance that keeps Candida under control is altered, the level of yeast increases & can develop into a thrush infection. Canesten Thrush Oral Capsule contains the active substance fluconazole, an antifungal agent which fights the cause of infections such as thrush.