There is no significant difference between the old Champix Summary of Product Characteristics (SPC) and the ones for generic varenicline.
Thanks to Kevin Irvine from Boots Digital Health for pointing out these small but important differences from the Champix SPC:
1. A gradual approach to quitting smoking with Varenicline should be considered for patients who are not able or willing to quit abruptly. Patients should reduce smoking during the first 12 weeks of treatment and quit by the end of that treatment period.
2. For patients who have successfully stopped smoking at the end of 12 weeks, an additional course of 12 weeks treatment with Varenicline at 1 mg twice daily may be considered for the maintenance of abstinence. Patients should then continue taking Varenicline for an additional 12 weeks for a total of 24 weeks of treatment.
The full Summary of Product Characteristics (SPC) for the Brown & Burke and Wave Pharma versions of varenicline are below. The SPC are where you can find all the information on usage, side effects, and drug interactions of varenicline - and they are essential reading.