Varenicline drug interactions

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Contents 1 Drug-drug interactions 2 Drug-food/drug-herb interactions 3 References	This page is not completed and has not been reviewed for accuracy. You are reading a non-certified PubDrug document. This document is incomplete and not ready for final editing, review, and certification. Until this document is certified, any registered PubDrug user may edit its content. Authored by: Tdwalsh 12:51, 18 September 2007 (PDT) Certified by: certifier signature (four tildes)
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Drug-drug interactions

Severity level	Drug and description of interaction
4	None known
3	None known
2	None known
1	None known

Drug-food/drug-herb interactions

Severity level	Drug and description of interaction
4	None known
3	None known
2	None known
1	None known

Note: No significant drug-drug interactions have been reported for varenicline. Those which do exist are clinically trivial. For example, when varenicline was co-administered with cimetidine (which is known to inhibit the OCT2 pathway through which varenicline is known to be secreted), varenicline serum levels were increased. Still, this interaction is too minor to warrant a dose adjustment.^[1][2]

It should also be noted that an interaction may exist between nicotine and varenicline. Patients who received both varenicline and transdermal nicotine experienced both an increase in side effects (such as nausea and headache) and, consequently, a higher drop-out rate. The pharmacokinetics of nicotine did not appear to be affected.^[1]

Further attention should be paid to drug-drug interactions involving nicotine, since a patient receiving varenicline will presumably cease taking nicotine. Some of the more significant interactions include warfarin (decreased plasma concentrations with nicotine), heparin (decreased T_1/2 with nicotine) and insulin (potentially reduced absorption with nicotine).^[3]

References

1. ↑ ^1.0 1.1 Chantix® (varenicline) package insert. New York, NY: Pfizer, Inc.; 2007 May.
2. ↑ Obach RS, Reed-Hagen AE, Krueger SS, Obach BJ, O’Connell TN, Zandi KS, et al. Metabolism and disposition of varenicline, a selective α4β2 acetylcholine receptor partial agonist, in vivo and in vitro. Drug Metab Dispos. 2006 January; 34(1):121-130.
3. ↑ Zevin S and Benowitz NL. Drug interactions with tobacco smoking: an update. Clinical Pharmacokinetics. 1999 June; 36(6):425-438.