- Side Effects
- Drug Interactions
- Things to Know
What is guanfacine? What is guanfacine used for?
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?
Is guanfacine-oral available as a generic drug?
Do I need a prescription for guanfacine-oral?
What are the side effects of guanfacine?
Use Intuniv with caution in patients at risk for hypotension, bradycardia, heart block, or syncope (e.g., those taking antihypertensives). Measure heart rate and blood pressure before initiation of therapy, following dose increases, and periodically while on therapy. Advise patients to avoid becoming dehydrated or overheated.
Sedation and somnolence occur commonly with Intuniv
Consider the potential for additive sedative effects with CNS depressant drugs. Caution patients against operating heavy equipment or driving until they know how they respond to Intuniv.
Common side effects
The most common side effects associated with guanfacine treatment are
Other important side effects that are rare, but serious, are:
What is the dosage for guanfacine?
Recommended dose: 1 to 4 mg once daily in the morning or evening.
- Begin at a dose of 1 mg once daily and adjust in increments of no more than 1 mg/week.
- Do not crush, chew or break tablets before swallowing.
- Do not administer high-fat meals, because of increased exposure.
- Do not substitute for immediate-release guanfacine tablets on an mg-per-mg basis, because of differing pharmacokinetic profiles.
- If switching from immediate-release guanfacine, discontinue that treatment and titrate with Intuniv as directed.
- Consider dosing on an mg/kg basis. Improvements were observed starting at doses of 0.05-0.08 mg/kg once daily. Doses up to 0.12 mg/kg once daily may provide additional benefits (2.2).
- When discontinuing, taper the dose in decrements of no more than 1 mg every 3 to 7 days.
Which drugs or supplements interact with guanfacine?
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.
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Is guanfacine safe to take if I'm pregnant or breastfeeding?
What else should I know about guanfacine?
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).
Guanfacine (Intuniv, Tenex) is a prescription medication used to treat ADHD and high blood pressure (hypertension). Check out the center below for more medical references on guanfacine, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.
Multimedia: Slideshows, Images & Quizzes
What Is High Blood Pressure (Hypertension)? Symptoms, Treatments
What causes high blood pressure (hypertension)? What is normal blood pressure? Know the warning signs and symptoms of high blood...
ADHD/ADD in Adults: Symptoms & Treatments in Pictures
Most people don't associate adults with the term ADHD (attention deficit hyperactivity disorder) but it is a common disorder in...
What Are the Symptoms of ADHD in Kids? Tests, Medication
What is ADHD (Attention Deficit Hyperactivity Disorder)? Learn to recognize ADHD symptoms in children.
Adult ADHD Quiz
What are the symptoms of adult ADHD? Take this quiz to learn what it means for an adult to suffer from ADHD and what can be done...
High Blood Pressure (Hypertension) Quiz: Symptoms, Signs & Causes
Take this quiz and test your IQ of high blood pressure (hypertension), the cardiovascular disease that causes most strokes and...
Childhood ADHD Quiz: Test, Symptoms & Medication
Find out causes, symptoms, and treatments for Attention Deficit Hyperactivity Disorder, a widespread behavioral condition...
ADHD in Children: Understanding, Discipline and Better Parenting
ADHD is a common disorder seen in children. Parents can learn tips and techniques to teach children life skills, coping...
Adult ADHD: Organization and Time-Management Tips in Pictures
Learn daily living tips for adult ADHD (Attention Deficit Hyperactivity Disorder). If you have ADHD or you just need to get...
Related Disease Conditions
High Blood Pressure (Hypertension)
High blood pressure (hypertension) is a disease in which pressure within the arteries of the body is elevated. About 75 million people in the US have hypertension (1 in 3 adults), and only half of them are able to manage it. Many people do not know that they have high blood pressure because it often has no has no warning signs or symptoms. Systolic and diastolic are the two readings in which blood pressure is measured. The American College of Cardiology released new guidelines for high blood pressure in 2017. The guidelines now state that blood normal blood pressure is 120/80 mmHg. If either one of those numbers is higher, you have high blood pressure. The American Academy of Cardiology defines high blood pressure slightly differently. The AAC considers 130/80 mm Hg. or greater (either number) stage 1 hypertension. Stage 2 hypertension is considered 140/90 mm Hg. or greater. If you have high blood pressure you are at risk of developing life threatening diseases like stroke and heart attack.REFERENCE: CDC. High Blood Pressure. Updated: Nov 13, 2017.
Things to Know About High Blood Pressure Treatment
High blood pressure (hypertension) means high pressure (tension) in the arteries. Treatment for high blood pressure include lifestyle modifications (alcohol, smoking, coffee, salt, diet, exercise), drugs and medications such as ACE inhibitors, angiotensin receptor blockers, beta blockers, diuretics, calcium channel blockers (CCBs), alpha blockers, clonidine, minoxidil, and Exforge.
What Is ADHD in Children?
Attention deficit hyperactivity disorder (ADHD) causes the following symptoms in children: excessive activity, problems concentrating, and difficulty controlling impulses. Stimulant medications are the most common medication used to treat ADHD.
13 Tips for Parenting a Teen With ADHD
Parenting a teenager who has attention deficit hyperactivity disorder (ADHD) can be challenging. Parents can use specific strategies to help their teen cope with school and homework. Special care should be taken to help an ADHD teen drive safely and avoid alcohol and drug use.
Adult ADHD (Attention Deficit Hyperactivity Disorder)
About 2%-6% of adults have ADHD, a common behavioral problem. Symptoms include impulsivity, hyperactivity, and inattention. Treatment may involve ADHD education, attending a support group, skills training, and medication.
Post-traumatic Stress Disorder
Post-traumatic stress disorder (PTSD), a psychiatric condition, can develop after any catastrophic life event. Symptoms include nightmares, flashbacks, sweating, rapid heart rate, detachment, amnesia, sleep problems, irritability, and exaggerated startle response. Treatment may involve psychotherapy, group support, and medication.
What Causes Tourette Syndrome?
The exact cause of Tourette syndrome isn't known. It is likely to be caused by an interplay between genetic and environmental factors such as certain infections. Recent research on Tourette syndrome has found problems in certain brain regions and neurotransmitters (dopamine, serotonin and norepinephrine) that transmit messages between the nerve cells. These abnormalities may be responsible for the symptoms in Tourette syndrome.
Attention Deficit Hyperactivity Disorder (ADHD) in Teens
Attention deficit hyperactivity disorder (ADHD) in teens is a disruption of neurocognitive functioning. Genetics contribute to ADHD. Symptoms of ADHD in teens include inattention, hyperactivity/impulsivity, or a combination of these. Treatment may include cognitive behavioral therapy, behavior therapy, medication, or alternative therapies.
Parenting a Child With ADHD
ADHD is a behavioral condition with characteristics that include hyperactivity, inattention, and impulsivity. Parenting a child with ADHD presents a variety of challenges. Treatment options for children with ADHD include medication and behavioral therapy.
Treatment & Diagnosis
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