• Basic Info
• Top Questions
• Clinical Info

What is this medicine?

GUANFACINE (GWAHN fa seen) is used to treat attention-deficit hyperactivity disorder (ADHD).

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

• heart disease
• kidney disease
• liver disease
• low blood pressure or slow heart rate
• an unusual or allergic reaction to guanfacine, other medicines, foods, dyes, or preservatives
• breast-feeding
• pregnant or trying to get pregnant

How should I use this medicine?

Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. Do not cut, crush or chew this medicine. Do not take this medicine with a high-fat meal. Take your medicine at regular intervals. Do not take it more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 6 years for selected conditions, precautions do apply.

Overdosage: If you think you've taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses. If you miss 2 or more doses in a row, you should contact your doctor or health care professional. You may need to restart your medicine at a lower dose.

What may interact with this medicine?

• barbiturate medicines for insomnia or treating seizures
• ketoconazole
• medicines for blood pressure
• phenytoin
• prescription pain medicines
• valproic acid

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular checks on your progress. Check your heart rate and blood pressure regularly while you are taking this medicine. Ask your doctor or health care professional what your heart rate should be and when you should contact him or her.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. To avoid dizzy or fainting spells, do not stand or sit up quickly, especially if you are an older person. Alcohol can make you more drowsy and dizzy. Avoid alcoholic drinks.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your doctor if the problem does not go away or is severe.

Avoid becoming dehydrated or overheated while taking this medicine.

Last Updated: September 09, 2009