Clonidine is efficacious but its usefulness is limited by a high incidence of side effects. It should be considered as a second-line therapy.

Clonidine should be regarded as a second-line pharmacotherapy for smokers who have not been helped by any of the NRTs, bupropion or varenicline, or who have contraindications to their use. This pharmacotherapy is not licensed for smoking cessation. Clonidine can be used as a pill or patch. Patients will need to be monitored closely for known adverse effects, such as hypotension and sedation. However, sedative effects may be desirable during the period of nicotine withdrawal if a smoker experiences extreme agitation and anxiety unrelieved by NRT. Clonidine could be added to, or used instead of, NRT in that circumstance.

Fiore MC, Bailey WC, Cohen SJ, et al. Treating Tobacco Use and Dependence. A Clinical Practice Guideline. Rockville, MD: US Department of Health and Human Services, 2000. http://www.surgeongeneral.gov/tobacco/treating_tobacco_use.pdf

Gourlay SG, Stead LF, Benowitz NL. Clonidine for smoking cessation (Cochrane Review). Cochrane Database of Systematic Reviews 2004; 3. http://www.cochrane.org/reviews/en/ab000058.html