guanfacine (Intuniv, Tenex)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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What is guanfacine-oral, and how does it work (mechanism of action)?

Guanfacine is an oral, centrally-acting alpha 2A adrenergic receptor agonist. It is available in two different formulations, Tenex immediate release tablets and Intuniv extended release tablets. Tenex is used alone or in combination with other medications for the treatment of hypertension (high blood pressure). Guanfacine reduces blood pressure by reducing the resistance of blood flow in the blood vessels, and by decreasing heart rate.

Intuniv (guanfacine extended release) is used alone or in combination with other medications for the treatment of attention deficit hyperactivity disorder (ADHD). The exact mechanism of action of guanfacine in ADHD is unknown. Extended release guanfacine is effective for the treatment of ADHD in children and adolescents between the ages of 6 to 17 in clinical trials lasting 8 weeks.

Guanfacine was approved by the US Food and Drug Administration (FDA) in 1986.

What brand names are available for guanfacine-oral?

Intuniv, Tenex

Is guanfacine-oral available as a generic drug?

GENERIC AVAILABLE: Yes

Do I need a prescription for guanfacine-oral?

: Yes

What are the side effects of guanfacine-oral?

The most common side effects associated with guanfacine treatment are

Other important side effects that are rare, but serious, are:

Quick GuideHow to Lower Blood Pressure: Exercise Tips

How to Lower Blood Pressure: Exercise Tips

What is the dosage for guanfacine-oral?

  • Extended release guanfacine for the treatment of ADHD The recommended dose is 1 to 4 mg by mouth in the morning or evening. Patients are usually started on 1 mg once daily which is then increased in increments no larger than 1 mg/week as needed or tolerated. Tablets should not be administered with high-fat meals.
  • Immediate release guanfacine for the treatment of hypertension The recommended dose is 1 mg usually at bedtime. The dose may be increased at 3 to 4 week intervals as necessary. The usual dose range is 0.5 to 2 mg once daily.

Which drugs or supplements interact with guanfacine-oral?

: Rifampin and St. John's wort may reduce blood levels of guanfacine by increasing its metabolism (breakdown) in the intestine; doses of guanfacine may need to be increased when combined with drugs that reduce its blood levels.

Other drugs that also may reduce blood levels of guanfacine include carbamazepine (Tegretol, Tegretol XR , Equetro, Carbatrol, Epitol, Teril), phenytoin (Dilantin, Dilantin-125), phenobarbital, oxcarbazepine (Trileptal), rifabutin, rifampin, rifapentine, bosentan (Tracleer), and tipranavir/ritonavir (Aptivus).

Ketoconazole (Nizoral, Extina, Xolegel, Kuric), itraconazole (Sporanox), and simeprevir (Olysio) may increase blood levels of guanfacine by decreasing its metabolism in the intestine; the dose of guanfacine may need to be decreased when combined with drugs that increase its blood levels.

Is guanfacine-oral safe to take if I'm pregnant or breastfeeding?

It is not known whether guanfacine is excreted in breast milk. Due to the lack of safety data, guanfacine should be used cautiously in nursing mothers.

What else should I know about guanfacine-oral?

What preparations of guanfacine-oral are available?

  • Intuniv: Extended-Release Tablets: 1, 2, 3, and 4 mg
  • Tenex: Immediate-Release Tablets: 1 and 2 mg

How should I keep guanfacine-oral stored?

Tablets should be stored at room temperature, between 15 C to 30 C (59 F to 86 F).

REFERENCE: FDA Prescribing Information.

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How to Lower Blood Pressure: Exercise Tips

Summary

guanfacine (Intuniv, Tenex) is a prescription medication. The brand Intuniv is prescribed to use alone or in combination to treat ADHD . The brand Tenex is prescribed to treat high blood pressure (hypertension). Side effects, drug intearctions, dosing, storage, and pregnancy safety information should be reviewed prior to taking this medicaiton.

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Reviewed on 9/11/2015
References
REFERENCE: FDA Prescribing Information.

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