Active Ingredient: Guanfacine
Guanfacine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in children and adolescents 6-17 years old for whom stimulants are not suitable, not tolerated or have been shown to be ineffective.
Guanfacine must be used as a part of a comprehensive ADHD treatment programme, typically including psychological, educational and social measures.
For this indication, competent medicine agencies globally authorize below treatments:
For:
Tablet, delated release oral, between 0.05 milligrams guanfacine per kilogram of body weight and 0.12 milligrams guanfacine per kilogram of body weight, once daily.
Treatment must be initiated under the supervision of an appropriate specialist in childhood and/or adolescent behavioural disorders.
Prior to prescribing, it is necessary to conduct a baseline evaluation to identify patients at increased risk of somnolence and sedation, hypotension and bradycardia, QT-prolongation arrhythmia and weight increase/risk of obesity. This evaluation should address a patient’s cardiovascular status including blood pressure and heart rate, documenting comprehensive history of concomitant medications, past and present co-morbid medical and psychiatric disorders or symptoms, family history of sudden cardiac/unexplained death and accurate recording of pre-treatment height and weight on a growth chart.
Careful dose titration and monitoring is necessary at the start of treatment with Intuniv since clinical improvement and risks for several clinically significant adverse reactions (syncope, hypotension, bradycardia, somnolence and sedation) are dose- and exposure-related. Patients should be advised that somnolence and sedation can occur, particularly early in treatment or with dose increases. If somnolence and sedation are judged to be clinically concerning or persistent, a dose decrease or discontinuation should be considered.
For all patients, the recommended starting dose is 1 mg of guanfacine, taken orally once a day.
The dose may be adjusted in increments of not more than 1 mg per week. Dose should be individualised according to the patient’s response and tolerability.
Depending on the patient’s response and tolerability for guanfacine the recommended maintenance dose range is 0.05-0.12 mg/kg/day. The recommended dose titration for children and adolescents is provided below (see tables 1 and 2). Dose adjustments (increase or decrease) to a maximum tolerated dose within the recommended optimal weight-adjusted dose range based upon clinical judgement of response and tolerability may occur at any weekly interval after the initial dose.
During dose titration, weekly monitoring for signs and symptoms of somnolence and sedation, hypotension and bradycardia should be performed.
During the first year of treatment, the patient should be assessed at least every 3 months for:
It is recommended clinical judgement be exercised during this period. 6 monthly monitoring should follow thereafter, with more frequent monitoring following any dose adjustments.
Table 1. Dose Titration Schedule for Children Aged 6-12 years:
| Weight Group | Week 1 | Week 2 | Week 3 | Week 4 |
|---|---|---|---|---|
| 25 kg and up Max Dose=4 mg | 1 mg | 2 mg | 3 mg | 4 mg |
Table 2. Dose Titration Schedule for Adolescents (Aged 13-17 Years):
| Weight Groupa | Week 1 | Week 2 | Week 3 | Week 4 | Week 5 | Week 6 | Week 7 |
|---|---|---|---|---|---|---|---|
| 34-41.4 kg Max Dose=4 mg | 1 mg | 2 mg | 3 mg | 4 mg | |||
| 41.5-49.4 kg Max Dose=5 mg | 1 mg | 2 mg | 3 mg | 4 mg | 5 mg | ||
| 49.5-58.4 kg Max Dose=6 mg | 1 mg | 2 mg | 3 mg | 4 mg | 5 mg | 6 mg | |
| 58.5 kg and above Max Dose=7 mg | 1 mg | 2 mg | 3 mg | 4 mg | 5 mg | 6 mg | 7 mgb |
a Adolescent subjects must weigh at least 34 kg.
b Adolescents weighing 58.5 kg and above may be titrated to a 7 mg/day dose after the subject has completed a minimum of 1 week of therapy on a 6 mg/day dose and the physician has performed a thorough review of the subject’s tolerability and efficacy.
The physician who elects to use guanfacine for extended periods (over 12 months) should re-evaluate the usefulness of guanfacine every 3 months for the first year and then at least yearly based on clinical judgement, and consider trial periods off medication to assess the patient’s functioning without pharmacotherapy, preferably during times of school holidays.
Patients/caregivers should be instructed not to discontinue guanfacine without consulting their physician.
When stopping Intuniv, the dose must be tapered with decrements of no more than 1 mg every 3 to 7 days, and blood pressure and pulse should be monitored in order to minimise potential withdrawal effects, in particular increases in blood pressure and heart rate.
In a maintenance of efficacy study, upon switching from guanfacine to placebo, 7/158 (4.4%) subjects experienced increases in blood pressure to values above 5 mmHg and also above the 95 th percentile for age, sex and stature.
In the event of a missed dose, Intuniv dosing can resume the next day. If two or more consecutive doses are missed, re-titration is recommended based on the patient’s tolerability to guanfacine.
Guanfacine is taken once daily either morning or evening. Tablets should not be crushed, chewed or broken before swallowing because this increases the rate of guanfacine release
Treatment is recommended only for children who are able to swallow the tablet whole without problems.
Guanfacine can be administered with or without food but should not be administered with high fat meals, due to increased exposure.
Guanfacine should not be administered together with grapefruit juice.
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