7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino(2,3-h)(3)benzazepine

Absorption
Absorption is virtually complete and exhibits linear pharmacokinetics. C max occurs within 3 to 4 h. Steady state is reached within 4 days.

Distribution
Plasma protein binding is 20% or less.

Metabolism
Minimal metabolism occurs.

Elimination
Elimination t ½ is approximately 24 h. Excretion is 92% unchanged in the urine.

Special Populations
Hepatic Function Impairment

Pharmacokinetics should not be affected.

Mild Renal Function Impairment
Pharmacokinetics unchanged.

Moderate Renal Function Impairment
Drug exposure increased 1.5-fold.

Severe Renal Function Impairment
Drug exposure increased 2.1-fold.

End-Stage Renal Disease
Drug exposure increased 2.7-fold.

Cimetidine
Coadministration increased the systemic exposure of varenicline 29%.

Insulin, theophylline, warfarin
Smoking cessation may alter the pharmacokinetics or pharmacodynamics of some drugs, necessitating dosage adjustment.

Transdermal nicotine
The incidence of adverse reactions may be increased with coadministration.