Clonidine (Catapres) for quitting smoking

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Clonidine (Catapres) for quitting smoking


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Clonidine is available by prescription in pill form.

Clonidine has not been approved by Health Canada or the U.S. Food and Drug Administration (FDA) for use in helping people to quit smoking. But the Tobacco Use and Dependence Clinical Practice Guideline Panel of the U.S. Public Health Service recommends it as a second-choice medicine for this use.1

The preferred medicines to help you quit smoking are nicotine replacement therapy, varenicline, and bupropion.

How It Works

Doctors normally use clonidine to treat high blood pressure. In some people, it reduces the craving for cigarettes. It is not entirely understood how clonidine does this.

Although clonidine is not normally used as a first-choice medicine for smoking cessation, some people find it calms them when they are dealing with tobacco withdrawal symptoms.

Why It Is Used

Doctors prescribe clonidine for people who want to quit smoking but cannot take the first-choice medicines (bupropion, varenicline, and nicotine replacement therapy) or have not been able to quit smoking by using those medicines.2

How Well It Works

People using clonidine were twice as likely to be successful at quitting smoking as people who were not using any medicine.1

Side Effects

The most common side effects of clonidine include:

  • Dry mouth (occurs in 40% of users).
  • Drowsiness (33%).
  • Dizziness (16%).
  • Sleepiness (10%).
  • Constipation (10%).

The clonidine patch may irritate the skin.

Clonidine lowers blood pressure, so monitor your blood pressure while you are taking this medicine. It can also cause depression. Low blood pressure may occur if you sit or stand up quickly (postural or orthostatic hypotension).

Suddenly stopping the use of clonidine can cause side effects. These effects include nervousness, agitation, headache, confusion, and tremor along with a sudden rise in blood pressure (rebound hypertension). You can avoid this by slowly decreasing clonidine over 2 to 4 days.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Side effects can limit clonidine's usefulness for helping people quit smoking. It often has more side effects than other medicines used to help people quit smoking.1

You begin using clonidine 3 to 4 days before your quit date to build up the level of medicine in your body.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Fiore MC, et al. (2000). Clinical Practice Guideline: Treating Tobacco Use and Dependence. Rockville, MD: U.S. Department of Health and Human Services. Also available online:
  2. Drugs for tobacco dependence (2003). Treatment Guidelines From the Medical Letter, 1(10): 65–68.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer John Hughes, MD - Psychiatry
Specialist Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Last Revised August 31, 2009

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.