The debate about marijuana usage in transplant candidates: recent medical evidence on marijuana health effectsCoffman, Kathy LCurrent Opinion in Organ Transplantation: April 2008 - Volume 13 - Issue 2 - p 189–195 doi: 10.1097/MOT.0b013e3282f56139 Ethical, legal and financial considerations: Edited by Kathy Coffman Abstract Author InformationAuthors Article MetricsMetrics Purpose of review Cannabis is currently the most widely used illicit substance in the world. The issue of how to handle transplant candidates with active use of cannabis is a commonly encountered one for transplant-selection committees. Recent findings Correlates of marijuana use include increased risk of use of other illicit substances, increased risk of affective disorders and psychosis, as well as impaired cognition and motor skills. Risk of fungal infections and possible effects on cellular immunity that may increase cancer risk have also been reported. Reliability of laboratory testing for cannabis is discussed. False-negatives may occur with stealth peroxidases and false-positives with efavirenz (Sustiva). Photometric immunoassay (EMITS) has a 3% false-positive rate. Using a cutoff point of 20 ng/ml with confirmation via GC/MS will give a ‘virtually 100% reliable accuracy’ in detecting cannabis abuse. Summary Guidelines on management of the problem should be based on objective medical evidence on the health effects of marijuana, as well as on the implications in the transplant setting where medical urgency can drive medical decision-making. A recent survey of 16 academic transplant centers showed little consensus on guidelines for length of abstinence prior to listing candidates for transplantation. Department of Psychiatry and Psychology, Cleveland Clinic Foundation, Cleveland, Ohio, USA Correspondence to Kathy L. Coffman, MD, FAPM, 9500 Euclid Avenue/P-57, Cleveland, OH 44195, USA Tel: +1 216 444 8832; fax: +1 216 445 7032; e-mail: firstname.lastname@example.org © 2008 Lippincott Williams & Wilkins, Inc.