AZOLES AND CONTRACEPTIVES
There are isolated reports of breakthrough bleeding and failure of combined oral contraceptives with fluconazole, itraconazole and ketoconazole. Conversely, both fluconazole and itraconazole have been shown to modestly increase serum levels of contraceptive steroids.
Although anecdotal reports suggest that these antifungals can rarely make hormonal contraception less reliable, the pharmacokinetic data suggest that, if anything, an enhanced effect of the combined hormonal contraceptives is likely. Note that, of all the drugs proven to decrease the efficacy of combined hormonal contraceptives, all have also been shown to decrease the steroid levels. Further- more, the manufacturers do not advise any special precautions when taking oral contraceptives and azoles. However, some consider that the data warrant consideration being given to the use of additional contraceptive measures. The theoretical teratogenic risk from these azoles may have a bearing on this.
Although anecdotal reports suggest that these antifungals can rarely make hormonal contraception less reliable, the pharmacokinetic data suggest that, if anything, an enhanced effect of the combined hormonal contraceptives is likely. Note that, of all the drugs proven to decrease the efficacy of combined hormonal contraceptives, all have also been shown to decrease the steroid levels. Further- more, the manufacturers do not advise any special precautions when taking oral contraceptives and azoles. However, some consider that the data warrant consideration being given to the use of additional contraceptive measures. The theoretical teratogenic risk from these azoles may have a bearing on this.