The smoking cessation drug varenicline (Champix®, Chantix®) has been added as a row to the interactive charts and will be included on the printed charts when they are next updated.
Drug interactions are not expected with varenicline as it has been shown in vitro not to inhibit or induce cytochrome P450 enzymes. Since less than 10% of varenicline is metabolised, CYP P450 inhibitors or inducers are unlikely to affect the pharmacokinetics of varenicline. In addition, in vitro studies indicate that drugs cleared by renal secretion are unlikely to be affected by varenicline.
Varenicline can be found on the charts in a new class “Smoking Cessation”. Bupropion, another drug used in smoking cessation therapy, is already listed on the charts under its original indication of “antidepressant”.