Clonidine is used to treat high blood pressure. It works by decreasing your heart rate and relaxing the blood vessels so that blood can flow more easily through the body.

Clonidine is also used in the treatment of Tourette's syndrome, migraine headaches, ulcerative colitis, menopausal hot flashes, alcohol withdrawal, and as an aid in smoking cessation therapy. Talk to your doctor about the possible risks of using this drug for your condition.

Clonidine controls high blood pressure but does not cure it. Continue to take clonidine even if you feel well. Do not stop taking clonidine without talking to your doctor. Do not stop taking clonidine suddenly, that can cause a rise in blood pressure and symptoms such as nervousness, headache, and confusion. Your doctor will probably decrease your dose gradually over a few days.

Special precautions

Before taking clonidine,

• Tell your doctor and pharmacist if you are allergic to clonidine or any other drugs.
• Tell your doctor if you have or have ever had coronary artery disease, kidney disease, or a heart attack.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking clonidine, call your doctor.
• If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking clonidine.
• You should know that this drug may make you drowsy or dizzy. Do not drive a car or operate machinery until you know how this drug affects you.
• Ask your doctor about the safe use of alcohol while you are using clonidine. Alcohol can make the side effects from clonidine worse.

Side effects

Although side effects from clonidine are not common, they can occur:

• dry mouth
• drowsiness
• dizziness
• constipation
• tiredness
• headache
• nervousness
• decreased sexual ability
• upset stomach
• vomiting
• rash

If you experience any of the following symptoms, call your doctor immediately:

• fainting
• increased or decreased heartbeat
• irregular heartbeat
• swollen ankles or feet

Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to clonidine.