GF is a regular patient at your pharmacy. His past medical history includes angina, dyslipidemia and hypertension. While picking up his medication this month, he informs you that he had a heart attack...

GF is a regular patient at your pharmacy. His past medical history includes angina, dyslipidemia and hypertension.   While picking up his medication this month, he informs you that he had a heart attack last week which was a wake-up call and wants to quit smoking.  He reports smoking about 1 pack/day (20 cigarettes) but doesn’t smoke his first cigarette until after he goes to work.

After a few weeks of therapy with success taking Varenicline, GF’s doctor informs him that his liver function tests indicate that he has moderate hepatic impairment and normal renal function. Which of the following is the most appropriate recommendation?