Patient handout
Guanfacine ER (Intuniv)
You have been prescribed guanfacine. This page explains what it is, what to expect, and when to call.
What it is
Guanfacine extended-release is a non-stimulant ADHD medication. It calms the brain's alarm system rather than stimulating it, which helps with impulsivity, irritability, and restlessness, and it is often used alongside a stimulant or when stimulants are not a good fit. It also lowers blood pressure, which is where most of its side effects come from. It is not a controlled substance.
How to take it
- Take it once a day at the same time, often at bedtime because it can cause sleepiness.
- Swallow the tablet whole. Do not crush or split it, and do not take it with a high-fat meal, which raises the amount absorbed.
- If you miss a dose, skip it and take the next one on time. Missing two or more days in a row can cause a blood-pressure rebound; call us.
- The dose is raised slowly, usually one step per week.
What to expect, and when
- Week 1 to 2: sleepiness, tiredness, and lightheadedness are the common early effects and usually ease.
- Week 2 to 4: irritability, impulsivity, and restlessness often begin to improve.
- Week 4 to 8: full benefit at the right dose.
- Blood pressure and pulse are checked at visits.
Common side effects
Sleepiness, fatigue, dizziness or lightheadedness when standing, dry mouth, constipation, slower heart rate, and lower blood pressure. Stand up slowly, especially at night.
Call the office the same day if
- Fainting or near-fainting
- A very slow heartbeat, chest pain, or shortness of breath
- Severe dizziness that does not settle
- A sudden rise in blood pressure, pounding headache, or anxiety after missed doses (rebound)
- Rash, swelling, or trouble breathing (call 911)
Stopping
Do not stop guanfacine suddenly. Stopping abruptly can cause a rebound rise in blood pressure and heart rate, with headache and anxiety. We taper it down over one to two weeks together.
Good to know
- Avoid alcohol and other sedatives while adjusting the dose. Do not drive until you know how it affects you.
- Tell us about any heart condition, low blood pressure, fainting, or kidney or liver problems.
- Tell other prescribers and your pharmacist, especially about blood-pressure medicines and sedatives.
Questions about this medication?
Alice Tran Psychiatric Care · 3060 Williams Drive, Suite 300, Fairfax, VA 22031
Call: (703) 791-9099 · Text: (703) 791-9031 · info@alicetrannp.com · alicetrannp.com
This handout is for education and is not a substitute for the instructions you received at your visit. Follow the dose on your prescription label. If anything here differs from what you were told, call the office. In an emergency, call 911. If you are in crisis, call or text 988.