-
Varenicline
- indication:For use as an aid in smoking cessation.
- pharmacologypharmacology:
- mechanism: Varenicline is an alpha-4 beta-2 neuronal nicotinic acetylcholine receptor partial agonist. The drug shows high selectiviyty for this receptor subclass, relative to other nicotinic receptors (>500-fold alpha-3 beta-4, >3500-fold alpha-7, >20,000-fold alpha-1 beta gamma delta) or non-nicotinic receptors and transporters (>2000-fold). The drug competitively inhibits the ability of nicotine to bind to and activate the alpha-4 beta-2 receptor. The drug exerts mild agonistic activity at this site, though at a level much lower than nicotine; it is presumed that this activation eases withdrawal symptoms.
- toxicity:
- absorprion:
- halflife: The elimination half-life of varenicline is approximately 24 hours
- roouteelimination: Varenicline undergoes minimal metabolism, with 92% excreted unchanged in the urine. Renal elimination of varenicline is primarily through glomerular filtration along with active tubular secretion possibly via the organic cation transporter, OCT2.
- volumedistribution:
- clearance: