Taking varenicline for smoking cessation: A rare cause of pulmonary thromboembolism with infarction

Varenicline (Champix (R), Chantix (R)) is a partial agonist of the alpha 4 beta 2 nicotinic acetylcholine receptor (nAChR) and a full agonist of the alpha 7 nAChR. It has been used for smoking cessation since 2006. Varenicline has been associated with adverse cardiovascular (CV) events, including myocardial infarction, which may be caused by activation of the alpha 7 nAChR receptor that in turn stimulates parasympathetic output from the brainstem to the heart, release of catecholamines, and has a prothrombotic effect. However, among the adverse CV events, the issue related to the varenicline-induced pulmonary thromboembolism (PTE) has not being addressed. We report a case of PTE with pulmonary infarction presenting as right flank pain that resulted from the use of varenicline (the total score of adverse drug reaction probability scale, 6; probable association between varenicline and pulmonary PTE) in a patient without underlying CV disease and in whom low probability of PTE (Wells score was zero) was identified. (C) 2017 Elsevier Inc. All rights reserved.