WARNINGS AND PRECAUTIONS
Hypotension/Bradycardia
Treatment with clonidine hydrochloride extended-release tablets can cause dose related decreases in blood pressure and heart rate. In patients that completed 5 weeks of treatment in a controlled, fixed-dose monotherapy study in pediatric patients, during the treatment period the maximum placebo-subtracted mean change in systolic blood pressure was -4.0 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -8.8 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in diastolic blood pressure was -4.0 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -7.3 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in heart rate was -4.0 beats per minute on clonidine hydrochloride extended-release tablets 0.2 mg/day and -7.7 beats per minute on clonidine hydrochloride extended-release tablets 0.4 mg/day.
During the taper period of the fixed-dose monotherapy study the maximum placebo-subtracted mean change in systolic blood pressure was +3.4 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -5.6 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in diastolic blood pressure was +3.3 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -5.4 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in heart rate was -0.6 beats per minute on clonidine hydrochloride extended-release tablets 0.2 mg/day and -3.0 beats per minute on clonidine hydrochloride extended-release tablets 0.4 mg/day.
Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Uptitrate clonidine hydrochloride extended-release tablets slowly in patients with a history of hypotension, and those with underlying conditions that may be worsened by hypotension and bradycardia; e.g., heart block, bradycardia, cardiovascular disease, vascular disease, cerebrovascular disease, or chronic renal failure. Use caution in treating patients who have a history of syncope or may have a condition that predisposes them to syncope, such as hypotension, orthostatic hypotension, bradycardia, or dehydration. Use clonidine hydrochloride extended-release tablets with caution in patients treated concomitantly with antihypertensives or other drugs that can reduce blood pressure or heart rate or increase the risk of syncope. Advise patients to avoid becoming dehydrated or overheated.
Sedation and Somnolence
Somnolence and sedation were commonly reported adverse reactions in clinical studies. In patients that completed 5 weeks of therapy in a controlled fixed dose pediatric monotherapy study, 31% of patients treated with 0.4 mg/day and 38% treated with 0.2 mg/day vs 7% of placebo treated patients reported somnolence as an adverse event. In patients that completed 5 weeks of therapy in a controlled flexible dose pediatric adjunctive to stimulants study, 19% of patients treated with clonidine hydrochloride extended-release tablets+stimulant vs 8% treated with placebo+stimulant reported somnolence. Before using clonidine hydrochloride extended-release tablets with other centrally active depressants (such as phenothiazines, barbiturates, or benzodiazepines), consider the potential for additive sedative effects. Caution patients against operating heavy equipment or driving until they know how they respond to treatment with clonidine hydrochloride extended-release tablets. Advise patients to avoid use with alcohol.
Abrupt Discontinuation
No studies evaluating abrupt discontinuation of clonidine hydrochloride extended-release tablets in children with ADHD have been conducted. In children and adolescents with ADHD, physicians should gradually reduce the dose of clonidine hydrochloride extended-release tablets in decrements of no more than 0.1 mg every 3 to 7 days. Patients should be instructed not to discontinue clonidine hydrochloride extended-release tablets therapy without consulting their physician due to the potential risk of withdrawal effects.
In adults with hypertension, sudden cessation of clonidine hydrochloride extended-release formulation treatment in the 0.2 to 0.6 mg/day range resulted in reports of headache, tachycardia, nausea, flushing, warm feeling, brief lightheadedness, tightness in chest, and anxiety.
In adults with hypertension, sudden cessation of treatment with immediate-release clonidine has, in some cases, resulted in symptoms such as nervousness, agitation, headache, and tremor accompanied or followed by a rapid rise in blood pressure and elevated catecholamine concentrations in the plasma.
Allergic Reactions
In patients who have developed localized contact sensitization to clonidine transdermal system, continuation of clonidine transdermal system or substitution of oral clonidine hydrochloride therapy may be associated with the development of a generalized skin rash.
In patients who develop an allergic reaction from clonidine transdermal system, substitution of oral clonidine hydrochloride may also elicit an allergic reaction (including generalized rash, urticaria, or angioedema).
Cardiac Conduction Abnormalities
The sympatholytic action of clonidine may worsen sinus node dysfunction and atrioventricular (AV) block, especially in patients taking other sympatholytic drugs. There have been post-marketing reports of patients with conduction abnormalities and/or taking other sympatholytic drugs who developed severe bradycardia requiring IV atropine, IV isoproterenol, and temporary cardiac pacing while taking clonidine. Uptitrate clonidine hydrochloride extended-release tablets slowly and monitor vital signs frequently in patients with cardiac conduction abnormalities or patients concomitantly treated with other sympatholytic drugs.
Other Clonidine-Containing Products
Clonidine, the active ingredient in clonidine hydrochloride extended-release tablets, is also approved as an antihypertensive. Do not use clonidine hydrochloride extended-release tablets in patients concomitantly taking other clonidine-containing products, (e.g. Catapres®).
USE IN SPECIFIC POPULATIONS
Pregnancy
Pregnancy Category C: Oral administration of clonidine hydrochloride to pregnant rabbits during the period of embryo/fetal organogenesis at doses of up to 80 mcg/kg/day (approximately 3 times the oral maximum recommended daily dose [MRHD] of 0.4 mg/day on a mg/m2 basis) produced no evidence of teratogenic or embryotoxic potential. In pregnant rats, however, doses as low as 15 mcg/kg/day (1/3 the MRHD on a mg/m2 basis) were associated with increased resorptions in a study in which dams were treated continuously from 2 months prior to mating and throughout gestation. Increased resorptions were not associated with treatment at the same or at higher dose levels (up to 3 times the MRHD) when treatment of the dams was restricted to gestation days 6-15. Increases in resorptions were observed in both rats and mice at 500 mcg/kg/day (10 and 5 times the MRHD in rats and mice, respectively) or higher when the animals were treated on gestation days 1-14; 500 mcg/kg/day was the lowest dose employed in this study. No adequate and well-controlled studies have been conducted in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should not be used during pregnancy unless clearly needed.
Nursing Mothers
Since clonidine hydrochloride is excreted in human milk, caution should be exercised when clonidine hydrochloride extended-release tablets are administered to a nursing woman.
Pediatric Use
A study was conducted in which young rats were treated orally with clonidine hydrochloride from day 21 of age to adulthood at doses of up to 300 mcg/kg/day, which is approximately 3 times the maximum recommended human dose (MRHD) of 0.4 mg/day on a mg/m2 basis. A slight delay in onset of preputial separation was seen in males treated with the highest dose (with a no-effect dose of 100 mcg/kg/day, which is approximately equal to the MRHD), but there were no drug effects on fertility or on other measures of sexual or neurobehavioral development.
Clonidine hydrochloride extended-release tablets have not been studied in children with ADHD less than 6 years old.
Patients with Renal Impairment
The impact of renal impairment on the pharmacokinetics of clonidine in children has not been assessed. The initial dosage of clonidine hydrochloride extended-release tablets should be based on degree of impairment. Monitor patients carefully for hypotension and bradycardia, and titrate to higher doses cautiously. Since only a minimal amount of clonidine is removed during routine hemodialysis, there is no need to give supplemental clonidine hydrochloride extended-release tablets following dialysis.
Adult Use in ADHD
Clonidine hydrochloride extended-release tablets have not been studied in adult patients with ADHD.
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