^ Pharmacodynamics
Clonidine is a known antihypertensive agent. By stimulating alpha2-adrenergic receptors in the brain stem, clonidine reduces sympathetic outflow from the central nervous system and decreases peripheral resistance, renal vascular resistance, heart rate, and blood pressure.
^ Patient Counseling Information
Advise the patient to read the FDA-approved Patient Labeling (Patient Information)
^ Description
Clonidine hydrochloride extended-release tablets are a centrally acting alpha2-adrenergic agonist available as 0.1 mg extended-release tablets for oral administration. Each 0.1 mg tablet is equivalent to 0.087 mg of the free base.
The inactive ingredients are sodium lauryl sulfate, lactose monohydrate, hypromellose, pregelatinized starch, colloidal silicon dioxide, and magnesium stearate. The formulation is designed to delay the absorption of active drug in order to decrease peak to trough plasma concentration differences. Clonidine hydrochloride is an imidazoline derivative and exists as a mesomeric compound. The chemical name is 2-(2,6 dichlorophenylamino)-2-imidazoline hydrochloride. The following is the structural formula:
C9H9Cl2N3∙HClMol. Wt. 266.56
Clonidine hydrochloride, USP is an odorless, bitter, white, crystalline substance soluble in water and alcohol.
^ Rebound Hypertension
Abrupt discontinuation of clonidine hydrochloride extended-release tablets can cause rebound hypertension. 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.
No studies evaluating abrupt discontinuation of clonidine hydrochloride in children with ADHD have been conducted; however, to minimize the risk of rebound hypertension, 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.
^ General Dosing Information
Clonidine hydrochloride is an extended-release tablet to be taken orally with or without food. Swallow tablets whole. Do not crush, chew, or break tablets because this will increase the rate of clonidine release.
Due to the lack of controlled clinical trial data and differing pharmacokinetic profiles, substitution of clonidine hydrochloride extended-release tablets for other clonidine products on a mg-per-mg basis is not recommended [see Clinical Pharmacology (12.3)].
^ Clinical Trial Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Two clonidine hydrochloride ADHD clinical studies (Study 1, CLON-301 and Study 2, CLON-302) evaluated 256 patients in two 8-week placebo-controlled studies.
A third clonidine hydrochloride ADHD clinical study (Study 3, SHN-KAP-401) evaluated 135 children and adolescents in a 40-week placebo-controlled randomized-withdrawal study.
^Principal Display Panel - Mg Tablet Bottle Label
Rx only
NDC 70069-044-01
Clonidine Hydrochloride
Extended-Release
Tablets
0.1 mg
60 Tablets
^ 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.
^3 Dosage Forms And Strengths
Clonidine hydrochloride extended-release tablets are available in a 0.1 mg strength formulation. The 0.1 mg tablets are white to off-white round, biconvex tablets with debossing: "U" on one side and "77" on the other side. Clonidine hydrochloride extended-release tablets must be swallowed whole and never crushed, cut or chewed.
^ Pediatric Use
The safety and efficacy of clonidine hydrochloride in the treatment of ADHD have been established in pediatric patients 6 to 17 years of age. Use of clonidine hydrochloride in pediatric patients 6 to 17 years of age is supported by three adequate and well-controlled studies; a short-term, placebo-controlled monotherapy trial, a short-term adjunctive therapy trial and a longer-term randomized monotherapy trial [see Clinical Studies (14)]. Safety and efficacy in pediatric patients below the age of 6 years has not been established.
^4 Contraindications
Clonidine hydrochloride extended-release tablets are contraindicated in patients with a history of a hypersensitivity reaction to clonidine. Reactions have included generalized rash, urticaria, and angioedema [see Adverse Reactions (6)].
^ How Supplied/storage And Handling
Clonidine hydrochloride extended-release tablet 0.1 mg is a white to off-white round, biconvex tablets with debossing: "U" on one side and "77" on the other side and supplied as follows.
Bottles of 60 tablets with child-resistant closure, NDC 70069-044-01
Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [See USP Controlled Room Temperature].
Dispense in a tight container as defined in the USP.
Keep clonidine hydrochloride extended-release tablets and all medicines out of the reach of children.
^ 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 extended-release tablets 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 extended-release tablets may also elicit an allergic reaction (including generalized rash, urticaria, or angioedema).
^ Hypotension/bradycardia
Treatment with clonidine hydrochloride extended-release tablets can cause dose-related decreases in blood pressure and heart rate [see Adverse Reactions (6.1)]. Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Titrate 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. In 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, advise patients to avoid becoming dehydrated or overheated. Monitor blood pressure and heart rate, and adjust dosages accordingly in patients treated concomitantly with antihypertensives or other drugs that can reduce blood pressure or heart rate or increase the risk of syncope.
^ Discontinuation
When discontinuing clonidine hydrochloride extended-release tablets, the total daily dose should be tapered in decrements of no more than 0.1 mg every 3 to 7 days to avoid rebound hypertension [see Warnings and Precautions (5.3)].
^ Clinical Studies
Efficacy of clonidine hydrochloride in the treatment of ADHD was established in children and adolescents (6 to 17 years) in:
^6 Adverse Reactions
The following serious adverse reactions are described in greater detail elsewhere in labeling:
^ Post-marketing Experience
The following adverse reactions have been identified during post-approval use of clonidine hydrochloride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These events exclude those already mentioned in 6.1:
Psychiatric: hallucinations
Cardiovascular: Q-T prolongation
^7 Drug Interactions
The following have been reported with other oral immediate release formulations of clonidine:
^ Controlled Substance
Clonidine hydrochloride is not a controlled substance and has no known potential for abuse or dependence.
^1 Indications And Usage
Clonidine hydrochloride extended-release tablets are indicated for the treatment of attention deficit hyperactivity disorder (ADHD) as monotherapy and as adjunctive therapy to stimulant medications [see Clinical Studies (14)].
^ Missed Doses
If patients miss a dose of clonidine hydrochloride extended-release tablets, they should skip that dose and take the next dose as scheduled. Do not take more than the prescribed total daily amount of clonidine hydrochloride extended-release tablets in any 24-hour period.
^ Dose Selection
The dose of clonidine hydrochloride extended-release tablets, administered either as monotherapy or as adjunctive therapy to a psychostimulant, should be individualized according to the therapeutic needs and response of the patient. Dosing should be initiated with one 0.1 mg tablet at bedtime, and the daily dosage should be adjusted in increments of 0.1 mg/day at weekly intervals until the desired response is achieved. Doses should be taken twice a day, with either an equal or higher split dosage being given at bedtime (see Table 1).
Doses of clonidine hydrochloride higher than 0.4 mg/day (0.2 mg twice daily) were not evaluated in clinical trials for ADHD and are not recommended.
When clonidine hydrochloride extended-release tablets are being added-on to a psychostimulant, the dose of the psychostimulant can be adjusted depending on the patient's response to clonidine hydrochloride extended-release tablets.
^ 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 versus 4% 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+stimulant versus 7% 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.
^ Mechanism Of Action
Clonidine stimulates alpha2-adrenergic receptors in the brain. Clonidine is not a central nervous system stimulant. The mechanism of action of clonidine in ADHD is not known.
^ 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. Titrate 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.