Imidazoles, such as clotrimazole and fluconazole, block ergosterol biosynthesis, impairing sterol production and repair in Candida cell membranes. This alters membrane functionality, disrupting cell membrane molecular transportation and signaling.³

A number of OTC clotrimazole preparations are available, and topical clotrimazole is suitable for vaginal candidiasis during pregnancy if there are no other complications; the course of treatment should last a week.¹⁵ OTC fluconazole can be taken as a single oral dose for isolated cases but requires a prescription for longer courses. Oral fluconazole for recurrent vulvovaginal thrush has a recommended dose of 150mg every three days for three doses, and then once weekly for six months.¹²

Metronidazole is used for bacterial infections with Gram-negative organisms, and against anaerobes and protozoa. Clindamycin is active against Gram-positive cocci and a range of anaerobes. Both can be used as gels for BV and have the advantage of only requiring a single dose. Oral metronidazole is also indicated for G vaginalis infection, either as a single 2g dose or at 400-500mg twice a day for a week.¹²

Dequalinium chloride 10mg vaginal tablets (Flumizin) were launched earlier this year, being licensed for BV with a treatment regime of once daily for six days. The drug is a surface-active agent, increasing cell wall permeability and causing loss of enzyme activity and cell death. "As the bactericidal effect of dequalinium chloride occurs within 30-60 minutes, the maximum local concentration within the first hour after application is considered crucial for the efficacy," says the SPC.¹⁵