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Due to a potential for additive effects such as bradycardia and AV block, caution is warranted 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. Amitriptyline in combination with clonidine enhances the manifestation of corneal lesions in rats. (See TOXICOLOGY .) 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. Carcinogenesis, Mutagenesis, Impairment of Fertility Chronic dietary administration of clonidine was not carcinogenic to rats (132 weeks) or mice (78 weeks) dosed, respectively, at up to 46 to 70 times the maximum recommended daily human dose as mg/kg (9 or 6 times the MRDHD on a mg/m 2 basis). There was no evidence of genotoxicity in the Ames test for mutagenicity or mouse micronucleus test for clastogenicity. Fertility of male and female rats was unaffected by clonidine doses as high as 150 mcg/kg (approximately 3 times the MRDHD). In a separate experiment, fertility of female rats appeared to be affected at dose levels of 500 to 2000 mcg/kg (10 to 40 times the oral MRDHD on a mg/kg basis; 2 to 8 times the MRDHD on a mg/m 2 basis). Pregnancy TERATOGENIC EFFECTS Pregnancy Category C Reproduction studies performed in rabbits at doses up to approximately 3 times the oral maximum recommended daily human dose (MRDHD) of CATAPRES (clonidine hydrochloride) produced no evidence of a teratogenic or embryotoxic potential in rabbits. In rats, however, doses as low as 1/3 the oral MRDHD (1/15 the MRDHD on a mg/m 2 basis) of clonidine were associated with increased resorptions in a study in which dams were treated continuously from 2 months prior to mating. Increased resorptions were not associated with treatment at the same or at higher dose levels (up to 3 times the oral MRDHD) when the dams were treated on gestation days 6-15. Increases in resorption were observed at much higher dose levels (40 times the oral MRDHD on mg/kg basis; 4 to 8 times the MRDHD on a mg/m 2 basis) in mice and rats treated on gestation days 1-14 (lowest dose employed in the study was 500 mcg/kg). No adequate well-controlled studies have been conducted in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Nursing Mothers As clonidine is excreted in human milk, caution should be exercised when CATAPRES-TTS is administered to a nursing woman. Pediatric Use Safety and effectiveness in pediatric patients below the age of twelve have not been established (See Warnings on Withdrawal ). Adverse ReactionsClinical trial experience with CATAPRES-TTS Most systemic adverse effects during CATAPRES-TTS therapy have been mild and have tended to diminish with continued therapy. In a 3-month multiclinic trial of CATAPRES-TTS in 101 hypertensive patients, the systemic adverse reactions were, dry mouth (25 patients) and drowsiness (12), fatigue (6), headache (5), lethargy and sedation (3 each), insomnia, dizziness, impotence/sexual dysfunction, dry throat (2 each) and constipation, nausea, change in taste and nervousness (1 each). In the above mentioned 3-month controlled clinical trial, as well as other uncontrolled clinical trials, the most frequent adverse reactions were dermatological and are described below. In the 3-month trial, 51 of the 101 patients had localized skin reactions such as erythema (26 patients) and/or pruritus, particularly after using an adhesive overlay throughout the 7-day dosage interval. Allergic contact sensitization to CATAPRES-TTS was observed in 5 patients. Other skin reactions were localized vesiculation (7 patients), hyperpigmentation (5), edema (3), excoriation (3), burning (3), papules (1), throbbing (1), blanching (1), and a generalized macular rash (1). In additional clinical experience, contact dermatitis resulting in treatment discontinuation was observed in 128 of 673 patients (about 19 in 100) after a mean duration of treatment of 37 weeks. The incidence of contact dermatitis was about 34 in 100 among white women, about 18 in 100 in white men, about 14 in 100 in black women, and approximately 8 in 100 in black men. Analysis of skin reaction data showed that the risk of having to discontinue CATAPRES-TTS treatment because of contact dermatitis was greatest between treatment weeks 6 and 26, although sensitivity may develop either earlier or later in treatment. In a large-scale clinical applicability and safety study by 451 physicians in a total of 3539 patients, other allergic reactions were recorded for which a causal relationship to CATAPRES-TTS was not established: maculopapular rash (10 cases); urticaria (2 cases); and angioedema of the face (2 cases), which also affected the tongue in one of the patients. Marketing Experience with CATAPRES-TTS Other adverse effects reported since the drug has been marketed are listed below by body system. In this setting, an incidence or causal relationship cannot always be accurately determined. However, none of the events listed below occurred in a frequency greater than 0.5%. Body as a Whole Cardiovascular Central and Peripheral Nervous System/Psychiatric Dermatological Gastrointestinal Genitourinary Metabolic Musculoskeletal Ophthalmological Adverse Events Associated with Oral CATAPRES Therapy: Most adverse events are mild and tend to diminish with continued therapy. The most frequent (which appear to be dose-related) are dry mouth, occurring in about 40 of 100 patients; drowsiness, about 33 in 100; dizziness, about 16 in 100; constipation and sedation, each about 10 in 100. The following less frequent adverse experiences have also been reported in patients receiving CATAPRES (clonidine hydrochloride USP), but in many cases patients were receiving concomitant medication and a causal relationship has not been established. Body as a Whole Cardiovascular Central Nervous System Dermatological Gastrointestinal Genitourinary Hematologic Metabolic Musculoskeletal Oro-otolaryngeal Ophthalmological OverdoseHypertension may develop early and may be followed by hypotension, bradycardia, respiratory depression, hypothermia, drowsiness, decreased or absent reflexes, weakness, irritability and miosis. The frequency of CNS depression may be higher in children than adults. Large overdoses may result in reversible cardiac conduction defects or dysrhythmias, apnea, coma and seizures. Signs and symptoms of overdose generally occur within 30 minutes to two hours after exposure. As little as 0.1 mg of clonidine has produced signs of toxicity in children. If symptoms of poisoning occur following dermal exposure, remove all CATAPRES-TTS systems. After their removal, the plasma clonidine levels will persist for about 8 hours, then decline slowly over a period of several days. Rare cases of CATAPRES-TTS poisoning due to accidental or deliberate mouthing or ingestion of the patch have been reported, many of them involving children. There is no specific antidote for clonidine overdosage. Ipecac syrup-induced vomiting and gastric lavage would not be expected to remove significant amounts of clonidine following dermal exposure. If the patch is ingested, whole bowel irrigation may be considered and the administration of activated charcoal and/or cathartic may be beneficial. Supportive care may include atropine sulfate for bradycardia, intravenous fluids and/or vasopressor agents for hypotension and vasodilators for hypertension. Naloxone may be a useful adjunct for the management of clonidine-induced respiratory depression, hypotension and/or coma; blood pressure should be monitored since the administration of naloxone has occasionally resulted in paradoxical hypertension. Tolazoline administration has yielded inconsistent results and is not recommended as first-line therapy. Dialysis is not likely to significantly enhance the elimination of clonidine. The largest overdose reported to date, involved a 28-year old male who ingested 100 mg of clonidine hydrochloride powder. This patient developed hypertension followed by hypotension, bradycardia, apnea, hallucinations, semicoma, and premature ventricular contractions. The patient fully recovered after intensive treatment. Plasma clonidine levels were 60 ng/mL after 1 hour, 190 ng/mL after 1.5 hours, 370 ng/mL after 2 hours, and 120 ng/mL after 5.5 and 6.5 hours. In mice and rats, the oral LD 50 of clonidine is 206 and 465 mg/kg, respectively. Dosage and AdministrationApply CATAPRES-TTS (clonidine) once every 7 days to a hairless area of intact skin on the upper outer arm or chest. Each new application of CATAPRES-TTS should be on a different skin site from the previous location. If the system loosens during 7-day wearing, the adhesive overlay should be applied directly over the system to ensure good adhesion. There have been rare reports of the need for patch changes prior to 7 days to maintain blood pressure control. To initiate therapy, CATAPRES-TTS dosage should be titrated according to individual therapeutic requirements, starting with CATAPRES-TTS-1. If after one or two weeks the desired reduction in blood pressure is not achieved, increase the dosage by adding another CATAPRES-TTS-1 or changing to a larger system. An increase in dosage above two CATAPRES-TTS-3 is usually not associated with additional efficacy. When substituting CATAPRES-TTS for oral clonidine or for other antihypertensive drugs, physicians should be aware that the antihypertensive effect of CATAPRES-TTS may not commence until 2-3 days after initial application. Therefore, gradual reduction of prior drug dosage is advised. Some or all previous antihypertensive treatment may have to be continued, particularly in patients with more severe forms of hypertension. Renal Impairment Dosage must be adjusted according to the degree of impairment, and patients should be carefully monitored. Since only a minimal amount of clonidine is removed during routine hemodialysis, there is no need to give supplemental clonidine following dialysis. How SuppliedCATAPRES-TTS-1 (clonidine) and CATAPRES-TTS-2 are supplied as 4 pouched systems and 4 adhesive overlays per carton, 3 cartons per shipper (NDC 0597-0031-12 and 0597-0032-12, respectively). CATAPRES-TTS-3 is supplied as 4 pouched systems and 4 adhesive overlays per carton (NDC 0597-0033-34). See chart below.
STORAGE AND HANDLING Store below 86° F (30° C). Rx only Manufactured by: Distributed by: PATIENT INSTRUCTIONS Catapres-TTS (clonidine) Transdermal Therapeutic System Catapres-TTS (clonidine) (Read the following instructions carefully before using this medication. If you have any questions, please consult with your doctor.) General Information CATAPRES-TTS is a square, tan adhesive PATCH containing an active blood-pressure- lowering medication. It is designed to deliver the drug into the body through the skin smoothly and consistently for one full week. Normal exposure to water, as in showering, bathing, and swimming, should not affect the PATCH. The optional white, round ADHESIVE COVER should be applied directly over the PATCH, should the PATCH begin to separate from the skin. The ADHESIVE COVER ensures that the PATCH sticks to the skin. The CATAPRES-TTS PATCH must be replaced with a new one on a fresh skin site if the one in use significantly loosens or falls off. How to Apply the CATAPRES-TTS PATCH 1) Apply the square, tan CATAPRES-TTS PATCH once a week, preferably at a convenient time on the same day of the week (i.e., prior to bedtime on Tuesday of week one; prior to bedtime on Tuesday of week two, etc.). 2) Select a hairless area such as on the upper, outer arm or upper chest. The area chosen should be free of cuts, abrasions, irritation, scars or calluses and should not be shaved before applying the CATAPRES-TTS PATCH. Do not place the CATAPRES-TTS PATCH on skin folds or under tight undergarments, since pre-mature loosening may occur. 3) Wash hands with soap and water and thoroughly dry them. 4) Clean the area chosen with soap and water. Rinse and wipe dry with a clean, dry tissue. 5) Select the pouch with the red and orange col- ors labeled CATAPRES-TTS (clonidine) and open it. Remove the square, tan PATCH from the pouch. 6) Remove the clear plastic protective backing from the PATCH by gently peeling off one half of the backing at a time. Avoid touching the sticky side of the CATAPRES-TTS® PATCH. . 7) Place the CATAPRES-TTS PATCH on the prepared skin site (sticky side down) by applying firm pressure over the PATCH to ensure good contact with the skin, especially around the edges (Figure 5). Discard the clear plastic protective backing and wash your hands with soap and water to remove any drug from your hands. 8) After one week, remove the old PATCH and discard it (refer to Instructions for Disposal). After choosing a different skin site, repeat instructions 2 through 7 for the application of your next CATAPRES-TTS PATCH. What to do if your Catapres-TTS PATCH becomes loose while wearing: How to Apply the ADHESIVE COVER Note: The white, round, ADHESIVE COVER does not contain any drug and should not be used alone. The COVER should be applied directly over the CATAPRES-TTS PATCH only if the PATCH begins to separate from the skin, thereby ensuring that it sticks to the skin for seven full days. 1) Wash hands with soap and water and thoroughly dry them. 2) Using a clean, dry tissue, make sure that the area around the square, tan CATAPRES-TTS PATCH is clean and dry. Press gently on the CATAPRES-TTS PATCH to ensure that the edges are in good contact with the skin. 3) Take the white, round, ADHESIVE COVER (Figure 6) from the plain white pouch and remove the paper liner backing from the COVER. 4) Carefully center the round, white ADHESIVE COVER over the square, tan CATAPRES-TTS PATCH and apply firm pressure, especially around the edges in contact with the skin. Instructions for Disposal KEEP OUT OF REACH OF CHILDREN During or even after use, a PATCH contains active medication which may be harmful to infants and children if accidentally applied or ingested. After use, fold in half with the sticky sides together. Dispose of carefully out of reach of children. Manufactured by: ALZA Corporation, Distributed by: Boehringer Ingelheim Pharmaceuticals, Inc., Licensed from: Boehringer Ingelheim International GmbH © Copyright Boehringer Ingelheim International GmbH 2004, Catapres-TTS patient information (in plain English) top . send to friend . medications homepage Reviewed: 08/2004
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