Clonidine

INDICATIONS AND USAGE Clonidine Hydrochloride Injection, USP is indicated in combination with opiates for the treatment of severe pain in cancer patients that is not adequately relieved by opioid analgesics alone. Epidural clonidine is more likely to be effective in patients with neuropathic pain than somatic or visceral pain (see CLINICAL PHARMACOLOGY: Clinical Trials ). The safety of this drug product has only been established in a highly selected group of cancer patients, and only after an adequate trial of opioid analgesia. Other use is of unproven safety and is not recommended. In a rare patient, the potential benefits may outweigh the known risks (see WARNINGS ).

DOSAGE AND ADMINISTRATION • Start with one 0.1 mg tablet at bedtime for one week. Increase daily dosage in increments of 0.1 mg/day at weekly intervals until the desired response is achieved. Take twice a day, with either an equal or higher split dosage being given at bedtime, as depicted below. ( 2.2 ) Total Daily Dose Morning Dose Bedtime Dose 0.1 mg/day 0.1 mg 0.2 mg/day 0.1 mg 0.1 mg 0.3 mg/day 0.1 mg 0.2 mg 0.4 mg/day 0.2 mg 0.2 mg • Do not crush, chew or break tablet before swallowing. ( 2.1 ) • Do not substitute for other clonidine products on a mg-per-mg basis, because of differing pharmacokinetic profiles. ( 2.1 ) • When discontinuing, taper the dose in decrements of no more than 0.1 mg every 3 to 7 days to avoid rebound hypertension. ( 2.3 ) 2.1 General Dosing Information Clonidine hydrochloride extended-release tablets are 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) ] . 2.2 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). Table 1 Clonidine Hydrochloride Extended-Release Tablets Dosing Guidance Total Daily Dose Morning Dose Bedtime Dose 0.1 mg/day 0.1 mg 0.2 mg/day 0.1 mg 0.1 mg 0.3 mg/day 0.1 mg 0.2 mg 0.4 mg/day 0.2 mg 0.2 mg Doses of clonidine hydrochloride extended-release tablets 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. 2.3 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) ] . 2.4 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.

WARNINGS AND PRECAUTIONS • Hypotension/bradycardia/syncope: Titrate slowly and monitor vital signs frequently in patients at risk for hypotension, heart block, bradycardia, syncope, cardiovascular disease, vascular disease, cerebrovascular disease or chronic renal failure. Measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy. Avoid concomitant use of drugs with additive effects unless clinically indicated. Advise patients to avoid becoming dehydrated or overheated. ( 5.1 ) • Somnolence/Sedation: Has been observed with clonidine hydrochloride extended-release tablets. 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 clonidine hydrochloride extended-release tablets. ( 5.2 ) • Cardiac Conduction Abnormalities: May worsen sinus node dysfunction and atrioventricular (AV) block, especially in patients taking other sympatholytic drugs. Titrate slowly and monitor vital signs frequently. ( 5.5 ) 5.1 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. 5.2 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 extended-release tablets +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. 5.3 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 extended-release tablets 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. 5.4 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). 5.5 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.

CONTRAINDICATIONS Clonidine hydrochloride injection is contraindicated in patients with a history of sensitization or allergic reactions to clonidine. Epidural administration is contraindicated in the presence of an injection site infection, in patients on anticoagulant therapy, and in those with a bleeding diathesis. Administration of clonidine hydrochloride injection above the C4 dermatome is contraindicated since there are no adequate safety data to support such use (see WARNINGS ).

Drug Interactions Clonidine may potentiate the CNS-depressive effects of alcohol, barbiturates or other sedating drugs. If a patient receiving clonidine hydrochloride is also taking tricyclic antidepressants, the hypotensive effect of clonidine may be reduced, necessitating an increase in the clonidine dose. If a patient receiving clonidine is also taking neuroleptics, orthostatic regulation disturbances (e.g., orthostatic hypotension, dizziness, fatigue) may be induced or exacerbated. Monitor heart rate in patients receiving clonidine concomitantly with agents known to affect sinus node function or AV nodal conduction, e.g., digitalis, calcium channel blockers, and beta-blockers. Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concomitantly with diltiazem or verapamil. Amitriptyline in combination with clonidine enhances the manifestation of corneal lesions in rats (see Toxicology ). Based on observations in patients in a state of alcoholic delirium it has been suggested that high intravenous doses of clonidine may increase the arrhythmogenic potential (QT-prolongation, ventricular fibrillation) of high intravenous doses of haloperidol. Causal relationship and relevance for clonidine oral tablets have not been established. Toxicology In several studies with oral clonidine hydrochloride, a dose-dependent increase in the incidence and severity of spontaneous retinal degeneration was seen in albino rats treated for six months or longer. Tissue distribution studies in dogs and monkeys showed a concentration of clonidine in the choroid. In view of the retinal degeneration seen in rats, eye examinations were performed during clinical trials in 908 patients before, and periodically after, the start of clonidine therapy. In 353 of these 908 patients, the eye examinations were carried out over periods of 24 months or longer. Except for some dryness of the eyes, no drug-related abnormal ophthalmological findings were recorded and, according to specialized tests such as electroretinography and macular dazzle, retinal function was unchanged. In combination with amitriptyline, clonidine hydrochloride administration led to the development of corneal lesions in rats within 5 days.

ADVERSE REACTIONS The following serious adverse reactions are described in greater detail elsewhere in labeling: Hypotension/bradycardia [see Warnings and Precautions (5.1) ] Sedation and somnolence [see Warnings and Precautions (5.2)] Rebound hypertension [see Warnings and Precautions (5.3)] Allergic reactions [see Warnings and Precautions (5.4)] Cardiac Conduction Abnormalities [see Warnings and Precautions (5.5)] Most common adverse reactions (incidence at least 5% and twice the rate of placebo) as monotherapy in ADHD: somnolence, fatigue, irritability, nightmare, insomnia, constipation, dry mouth. ( 6.1 ) Most common adverse reactions (incidence at least 5% and twice the rate of placebo) as adjunct therapy to psychostimulant in ADHD: somnolence, fatigue, decreased appetite, dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Teva at 1-888-838-2872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 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 extended-release tablet 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 extended-release tablet ADHD clinical study (Study 3, SHN-KAP-401) evaluated 135 children and adolescents in a 40- week placebo-controlled randomized-withdrawal study. Study 1: Fixed-dose Clonidine Hydrochloride Extended-Release Tablets Monotherapy Study 1 (CLON-301) was a short-term, multi-center, randomized, double-blind, placebo-controlled study of two fixed doses (0.2 mg/day or 0.4 mg/day) of clonidine hydrochloride extended-release tablets in children and adolescents (6 to 17 years of age) who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes. Most Common Adverse Reactions (incidence of greater than or equal to 5% and at least twice the rate of placebo): somnolence, fatigue, irritability, insomnia, nightmare, constipation, dry mouth. Adverse Events Leading to Discontinuation of Clonidine Hydrochloride Extended-Release Tablets – Five patients (7%) in the low dose group (0.2 mg), 15 patients (20%) in the high dose group (0.4 mg), and 1 patient in the placebo group (1%) reported adverse reactions that led to discontinuation. The most common adverse reactions that led to discontinuation were somnolence and fatigue. Commonly observed adverse reactions (incidence of greater than or equal to 2% in either active treatment group and greater than the rate on placebo) during the treatment period are listed in Table 2. Commonly observed adverse reactions (incidence of greater than or equal to 2% in either active treatment group and greater than the rate on placebo) during the taper period are listed in Table 3. Table 2 Common Adverse Reactions in the Fixed-Dose Monotherapy Trial - Treatment Period (Study 1) Percentage of Patients Reporting Event Clonidine Hydrochloride Extended-Release Tablets Clonidine Hydrochloride Extended-Release Tablets 0.2 mg/day 0.4 mg/day Placebo Preferred Term N=76 N=78 (N=76) PSYCHIATRIC DISORDERS Somnolence* 38% 31% 4% Nightmare 4% 9% 0% Emotional Disorder 4% 4% 1% Aggression 3% 1% 0% Tearfulness 1% 3% 0% Enuresis 0% 4% 0% Sleep Terror 3% 0% 0% Poor Quality Sleep 0% 3% 1% NERVOUS SYSTEM DISORDERS Headache 20% 13% 16% Insomnia 5% 6% 1% Tremor 1% 4% 0% Abnormal Sleep-Related Event 3% 1% 0% GASTROINTESTINAL DISORDERS Upper Abdominal Pain 15% 10% 12% Nausea 4% 5% 3% Constipation 1% 6% 0% Dry Mouth 0% 5% 1% GENERAL DISORDERS Fatigue† 16% 13% 1% Irritability 9% 5% 4% CARDIAC DISORDERS Dizziness 7% 3% 5% Bradycardia 0% 4% 0% INVESTIGATIONS Increased Heart Rate 0% 3% 0% METABOLISM AND NUTRITION DISORDERS Decreased Appetite 3% 4% 4% * Somnolence includes the terms "somnolence" and "sedation". † Fatigue includes the terms "fatigue" and "lethargy". Table 3 Common Adverse Reactions in the Fixed-Dose Monotherapy Trial - Taper Period* (Study 1) Percentage of Patients Reporting Event Clonidine Hydrochloride Extended-Release Tablets Clonidine Hydrochloride Extended-Release Tablets 0.2 mg/day 0.4 mg/day Placebo Preferred Term N=76 N=78 (N=76) Abdominal Pain Upper 0% 6% 3% Headache 5% 2% 3% Gastrointestinal Viral 0% 5% 0% Somnolence 2% 3% 0% Heart Rate Increased 0% 3% 0% Otitis Media Acute 3% 0% 0% * Taper Period: 0.2 mg dose, week 8; 0.4 mg dose, weeks 6 to 8; Placebo dose, weeks 6 to 8 Study 2: Flexible-dose Clonidine Hydrochloride Extended-Release Tablets as Adjunctive Therapy to Psychostimulants Study 2 (CLON-302) was a short-term, randomized, double-blind, placebo-controlled study of a flexible dose of clonidine hydrochloride extended-release tablets as adjunctive therapy to a psychostimulant in children and adolescents (6 to 17 years) who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes during which clonidine hydrochloride extended-release tablets were initiated at 0.1 mg/day and titrated up to 0.4 mg/day over a 3-week period. Most clonidine hydrochloride extended-release tablet treated patients (75.5%) were escalated to the maximum dose of 0.4 mg/day. Most Common Adverse Reactions (incidence of greater than or equal to 5% and at least twice the rate of placebo): somnolence, fatigue, decreased appetite, dizziness. Adverse Events Leading to Discontinuation – There was one patient in the CLON+STM group (1%) who discontinued because of an adverse event (severe bradyphrenia, with severe fatigue). Commonly observed adverse reactions (incidence of greater than or equal to 2% in the treatment group and greater than the rate on placebo) during the treatment period are listed in Table 4. Table 4 Common Adverse Reactions in the Flexible-Dose Adjunctive to Stimulant Therapy Trial - Treatment Period (Study 2) Percentage of Patients Reporting Event Clonidine Hydrochloride Extended-Release Tablets +STM PBO+STM Preferred Term (N=102) (N=96) PSYCHIATRIC DISORDERS Somnolence* 19% 7% Aggression 2% 1% Affect Lability 2% 1% Emotional Disorder 2% 0% GENERAL DISORDERS Fatigue † 14% 4% Irritability 2% 7% NERVOUS SYSTEM DISORDERS Headache 7% 12% Insomnia 4% 3% GASTROINTESTINAL DISORDERS Upper Abdominal Pain 7% 4% RESPIRATORY DISORDERS Nasal Congestion 2% 2% METABOLISM AND NUTRITION DISORDERS Decreased Appetite 6% 3% CARDIAC DISORDERS Dizziness 5% 1% * Somnolence includes the terms: "somnolence" and "sedation". † Fatigue includes the terms "fatigue" and "lethargy". Commonly observed adverse reactions (incidence of greater than or equal to 2% in the treatment group and greater than the rate on placebo) during the taper period are listed in Table 5. Table 5 Common Adverse Reactions in the Flexible-Dose Adjunctive to Stimulant Therapy Trial - Taper Period* (Study 2) Percentage of Patients Reporting Event Preferred Term Clonidine Hydrochloride Extended-Release Tablets +STM (N=102) PBO+STM (N=96) Nasal Congestion 4% 2% Headache 3% 1% Irritability 3% 2% Throat Pain 3% 1% Gastroenteritis Viral 2% 0% Rash 2% 0% * Taper Period: weeks 6 to 8 Adverse Reactions Leading to Discontinuation Thirteen percent (13%) of patients receiving clonidine hydrochloride extended-release tablets discontinued from the pediatric monotherapy study due to adverse events, compared to 1% in the placebo group. The most common adverse reactions leading to discontinuation of clonidine hydrochloride extended-release tablets monotherapy treated patients were from somnolence/sedation (5%) and fatigue (4%). Effect on 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.

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Clonidine stimulates alpha 2 -adrenergic receptors in the brain. Clonidine is not a central nervous system stimulant. The mechanism of action of clonidine in ADHD is not known. 12.2 Pharmacodynamics Clonidine is a known antihypertensive agent. By stimulating alpha 2 -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. 12.3 Pharmacokinetics Single-dose Pharmacokinetics in Adults Immediate-release clonidine hydrochloride and clonidine hydrochloride extended-release have different pharmacokinetic characteristics; dose substitution on a milligram for milligram basis will result in differences in exposure. A comparison across studies suggests that the C max is 50% lower for clonidine hydrochloride extended-release compared to immediate-release clonidine hydrochloride. Following oral administration of an immediate release formulation, plasma clonidine concentration peaks in approximately 3 to 5 hours and the plasma half-life ranges from 12 to 16 hours. The half-life increases up to 41 hours in patients with severe impairment of renal function. Following oral administration about 40% to 60% of the absorbed dose is recovered in the urine as unchanged drug in 24 hours. About 50% of the absorbed dose is metabolized in the liver. Although studies of the effect of renal impairment and studies of clonidine excretion have not been performed with clonidine hydrochloride extended-release, results are likely to be similar to those of the immediate release formulation. The pharmacokinetic profile of clonidine hydrochloride extended-release tablet administration was evaluated in an open-label, three-period, randomized, crossover study of 15 healthy adult subjects who received three single-dose regimens of clonidine: 0.1 mg of clonidine hydrochloride extended-release tablets under fasted conditions, 0.1 mg of clonidine hydrochloride extended-release tablets following a high fat meal, and 0.1 mg of clonidine hydrochloride immediate-release under fasted conditions. Treatments were separated by one-week washout periods. Mean concentration-time data from the 3 treatments are shown in Table 7 and Figure 1. After administration of clonidine hydrochloride extended-release tablets, maximum clonidine concentrations were approximately 50% of the clonidine hydrochloride immediate-release maximum concentrations and occurred approximately 5 hours later relative to clonidine hydrochloride immediate-release. Similar elimination half-lives were observed and total systemic bioavailability following clonidine hydrochloride extended-release tablets was approximately 89% of that following clonidine hydrochloride immediate-release. Food had no effect on plasma concentrations, bioavailability, or elimination half-life. Table 7 Pharmacokinetic Parameters of Clonidine in Healthy Adult Volunteers Clonidine Hydrochloride Immediate-Release-Fasted Clonidine Hydrochloride Extended-Release-Fed Clonidine Hydrochloride Extended-Release -Fasted n=15 n=15 n=14 Parameter Mean SD Mean SD MEAN SD C max (pg/mL) 443 59.6 235 34.7 258 33.3 AUC inf 7313 1812 6505 1728 6729 1650 (hr*pg/mL) hT max (hr) 2.07 0.5 6.80 3.61 6.50 1.23 T 1/2 (hr) 12.57 3.11 12.67 3.76 12.65 3.56 Figure 1: Mean Clonidine Concentration-Time Profiles after Single Dose Administration Multiple-dose Pharmacokinetics in Children and Adolescents Plasma clonidine concentrations in children and adolescents (0.1 mg bid and 0.2 mg bid) with ADHD are greater than those of adults with hypertension with children and adolescents receiving higher doses on a mg/kg basis. Body weight normalized clearance (CL/F) in children and adolescents was higher than CL/F observed in adults with hypertension. Clonidine concentrations in plasma increased with increases in dose over the dose range of 0.2 to 0.4 mg/day. Clonidine CL/F was independent of dose administered over the 0.2 to 0.4 mg/day dose range. Clonidine CL/F appeared to decrease slightly with increases in age over the range of 6 to 17 years, and females had a 23% lower CL/F than males. The incidence of "sedation-like" AEs (somnolence and fatigue) appeared to be independent of clonidine dose or concentration within the studied dose range in the titration study. Results from the add-on study showed that clonidine CL/F was 11% higher in patients who were receiving methylphenidate and 44% lower in those receiving amphetamine compared to subjects not on adjunctive therapy. Figure 1: Mean Clonidine Concentration-Time Profiles after Single Dose Administration