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Intuniv (Guanfacine Hydrochloride) - Indications and Dosage

 
 



INDICATIONS AND USAGE

INTUNIVis indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). The efficacy of INTUNIVwas studied for the treatment of ADHD in two controlled clinical trials (8 and 9 weeks in duration) in children and adolescents ages 6-17 who met DSM-IV® criteria for ADHD [see Clinical Studies ]. The effectiveness of INTUNIV for long-term use (more than 9 weeks) has not been systematically evaluated in controlled trials.

A diagnosis of ADHD implies the presence of hyperactive-impulsive and/or inattentive symptoms that cause impairment and were present before the age of 7 years. The symptoms must cause clinically significant impairment, e.g., in social, academic, or occupational functioning, and be present in two or more settings, e.g., school (or work) and at home. The symptoms must not be better accounted for by another mental disorder. For the Inattentive Type, at least six of the following symptoms must have persisted for at least 6 months: lack of attention to details/careless mistakes; lack of sustained attention; poor listener; failure to follow through on tasks; poor organization; avoids tasks requiring sustained mental effort; loses things; easily distracted; forgetful. For the Hyperactive-Impulsive Type, at least six of the following symptoms must have persisted for at least 6 months: fidgeting/squirming; leaving seat; inappropriate running/climbing; difficulty with quiet activities; "on the go"; excessive talking; blurting answers; can't wait turn; intrusive. The Combined Type requires both inattentive and hyperactive-impulsive criteria to be met.

Special Diagnostic Considerations

Specific etiology of this syndrome is unknown, and there is no single diagnostic test. Adequate diagnosis requires the use not only of medical but also of special psychological, educational, and social resources. Learning may or may not be impaired. The diagnosis must be based upon a complete history and evaluation of the patient and not solely on the presence of the required number of DSM-IV® characteristics.

Need for Comprehensive Treatment Program

INTUNIV™ is indicated as an integral part of a total treatment program for ADHD that may include other measures (psychological, educational, and social) for patients with this syndrome. Drug treatment may not be indicated for all patients with this syndrome. INTUNIV™ is not intended for use in patients who exhibit symptoms secondary to environmental factors and/or other primary psychiatric disorders, including psychosis. Appropriate educational/vocational placement is essential and psychosocial intervention is often helpful. When remedial measures alone are insufficient, the decision to prescribe INTUNIV™ will depend upon the physician's assessment of the chronicity and severity of the patient's symptoms and on the level of functional impairment.

DOSAGE AND ADMINISTRATION

General Dosing Information

INTUNIVis an extended-release tablet and should be dosed once daily. Tablets should not be crushed, chewed or broken before swallowing because this will increase the rate of guanfacine release. Do not administer with high fat meals, due to increased exposure.

Do not substitute for immediate-release guanfacine tablets on a mg-mg basis, because of differing pharmacokinetic profiles. INTUNIV has a delayed Tmax, reduced Cmax and lower bioavailability compared to those of the same dose of immediate-release guanfacine [see Clinical Pharmacology ].

Dose Selection

If switching from immediate-release guanfacine, discontinue that treatment, and titrate with INTUNIV according to the following recommended schedule.

Begin at a dose of 1 mg/day, and adjust in increments of no more than 1 mg/week.

Maintain the dose within the range of 1-4 mg once daily, depending on clinical response and tolerability. In clinical trials, patients were randomized to doses of 1 mg, 2 mg, 3 mg or 4 mg and received INTUNIVonce daily in the morning [see Clinical Studies ].

Clinically relevant improvements were observed beginning at doses in the range 0.05-0.08 mg/kg once daily. Efficacy increased with increasing weight-adjusted dose (mg/kg). If well tolerated, doses up to 0.12 mg/kg once daily may provide additional benefit. Doses above 4mg/day have not been studied.

In clinical trials, there were dose-related and exposure-related risks for several clinically significant adverse reactions (hypotension, bradycardia, sedative events). Thus, consideration should be given to dosing INTUNIV™ on a mg/kg basis, in order to balance the exposure-related potential benefits and risks of treatment.

Maintenance Treatment

The effectiveness of INTUNIV for longer-term use (more than 9 weeks) has not been systematically evaluated in controlled trials. Therefore the physician electing to use INTUNIV for extended periods should periodically re-evaluate the long-term usefulness of the drug for the individual patient.

Discontinuation

In a pharmacodynamic study in healthy young adult volunteers receiving INTUNIV (4 mg once daily) or placebo, the effects of abrupt discontinuation were compared to tapering. There were greater mean increases in systolic and diastolic blood pressure and heart rate after abrupt discontinuation of INTUNIV, but these changes generally reflected a return to original baseline and were not meaningfully different for the two discontinuation strategies. However, infrequent, transient elevations in blood pressure above original baseline (i.e., rebound) have been reported to occur upon abrupt discontinuation of guanfacine. To minimize these effects, the dose should generally be tapered in decrements of no more than 1 mg every 3 to 7 days.

Missed Doses

When reinitiating patients to the previous maintenance dose after two or more missed consecutive doses, physicians should consider titration based on patient tolerability.

DOSAGE FORMS and STRENGTHS

1 mg, 2 mg, 3 mg and 4 mg extended-release tablets

1 mg 2 mg 3 mg 4 mg
Color White/off-white White/off-white Green Green
Shape Round Caplet Round Caplet
Debossment (top/bottom) 503 / 1mg 503 / 2mg 503 / 3mg 503 / 4mg

HOW SUPPLIED/STORAGE AND HANDLING

INTUNIVis supplied in 1 mg, 2 mg, 3 mg, and 4 mg strength extended-release tablets in 100 count bottles.

1 mg 2 mg 3 mg 4 mg
Color White/off-white White/off-white Green Green
Shape Round Caplet Round Caplet
Debossment (top/bottom) 503 / 1mg 503 / 2mg 503 / 3mg 503 / 4mg
NDC number 54092-513-02 54092-515-02 54092-517-02 54092-519-02

Storage - Store at 25C (77F); excursions permitted to 15 to 30C (59 to 86F). See USP Controlled Room Temperature.

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