Key facts about Guanfacine
What dosages is Guanfacine available in?
Guanfacine is available as a 1 mg, 2 mg, 3 mg, and 4 mg extended-release oral tablet.
What is Guanfacine used for?
Guanfacine is an alpha 2A-adrenergic receptor agonist and is used to treat attention-deficit hyperactivity disorder (ADHD).
How does Guanfacine work?
Guanfacine is an alpha-2A agonist. It’s not clear how Guanfacine works to treat attention-deficit hyperactivity disorder (ADHD). It’s thought to work by lowering the amount of norepinephrine (a chemical in your brain) in certain parts of your brain that are involved with attention and focus.
How do I take Guanfacine?
Guanfacine is typically dosed as 1 mg by mouth once daily, either in the morning or evening. Your provider will raise the dose based on your body weight, age, and whether or not you’re taking other medications for ADHD. The typical maintenance dose ranges from 2 mg to 7 mg daily.
Is it safe for me to take Guanfacine?
Guanfacine is a safe and effective treatment when used for FDA licensed indications. However, like all medications, they may give you unwanted side effects. You should always discuss potential side effects with your physician to ensure the medication is suitable and right for you. You should not use this medication if you have a history of hypersensitivity to Guanfacine, its inactive ingredients, or other products containing Guanfacine.
Guanfacine Common Side Effects
Common side effects of Guanfacine include:
- Sleepiness
- Tiredness
- Low blood pressure
- Nausea
- Lack of energy
- Dizziness
Guanfacine Serious Side Effects
Serious side effects are rare with Guanfacine. Contact your healthcare provider immediately if you experience any of the following.
- Dangerously low blood pressure: feeling dizzy, tired, or out of breath easily
- Heart problems: lightheadedness, fainting, feeling like your heart is racing
Effects of other drugs, drug classes and over-the-counter products on Guanfacine
The following medications may interact with Guanfacine:
- Strong CYP3A4 inhibitors (e.g., ketoconazole): Coadministration increases Guanfacine exposure. Guanfacine dose should be limited to no more than 2 mg/day. When discontinuing CYP3A4 inhibitors, Guanfacine dose should be doubled based on patient tolerability. The maximum dose should not exceed 4 mg/day
- Strong CYP3A4 inducers (e.g., rifampin): Coadministration decreases Guanfacine exposure Guanfacine dose may be titrated up to 8 mg/day. When discontinuing CYP3A4 inducers, Guanfacine dose should be decreased by half in 1-2 weeks based on patient
- tolerability. The maximum dose should not exceed 4 mg/day
Who makes Guanfacine?
Various FDA-approved generic manufacturers
Is Guanfacine safe in pregnancy?
It is not known if Guanfacine will harm your unborn baby. You should talk to your healthcare provider before taking this medication if you are pregnant.













