
Data suggest that addition of amphetamine to varenicline may negate the partial agonism of varenicline, resulting in elimination of the smoking-cessation aid's benefits.
An 18-year-old man with attention-deficit-hyperactivity disorder (ADHD) was prescribed varenicline for smoking cessation.He quit smoking after 1 week of therapy and remained smoke free for the next 17 days. During that time, he had also been taking amphetamine-dextroamphetamine (Adderall) on work days for his ADHD.
Because his supply of amphetamine-dextroamphetamine was diminishing, he took only half (30 mg every morning) of his prescribed dosage from days 4-12 of varenicline therapy. He further reduced his dosage to 15 mg every morning on days 13 and 14 of varenicline therapy, and his supply of amphetamine-dextroamphetamine was depleted on day 15.
On day 23 of varenicline therapy, he received and filled a new prescription for amphetamine-dextroamphetamine and resumed his prescribed dosage (30 mg twice/day).
He began smoking again within 48 hours.
Rechallenge with varenicline while the patient continued to receive amphetamine-dextroamphetamine yielded similar results.
Data suggest that addition of amphetamine to varenicline may negate the partial agonism of varenicline, resulting in elimination of the smoking-cessation aid's benefits.
Other potential mechanisms for the drug interaction may also exist. Thus, varenicline may not aid smoking cessation in patients undergoing treatment with amphetamine and amphetamine-like drugs. [...]


I knew it.
I'm on both and the Chantix doesn't really work. The dex makes me smoke and the Chantix kills the buzz from it. But it's not disgusting or anything, it's just sort of joyless, but still compelling.