Transdermal patches clonidine

Clonidine is also available as a transdermal patch (Catapres-TTS [transdermal therapeutic system]) that has the advantages of avoiding the need for repeated doses during the day and of reportedly lower rates of dry mouth and drowsiness (Burris, 1993). Steady-state plasma levels are reached within 2-3 days after applying the patch and clonidine concentrations reportedly diminish gradually over 2-3 days following patch removal, without rebound hypertension in adult hyper-... 

Nicotine dependence may respond to replacement therapy with either nicotine gum or transdermal patches, and detoxification from nicotine dependence has been described using clonidine. Bupropion, an antidepressant, also shows efficacy for smoking cessation. The nicotinic receptor blocker mecamylamine, which has good central nervous system access, has been used with limited efficacy. Overall, success rates for smoking abstinence at 1 year are about 20%, with even less success for depressed smokers. 

Catapres TTS is the first and only transdermal patch approved by the FDA for the treatment of hypertension. Catapres TTS contains the active ingredient clondidine and was approved in 1985 [27], Catapres TTS is a seven-day patch and is a membrane-moderated transdermal patch. The patch comes in three sizes, 0.1, 0.2, and 0.3 mg/day. In addition there is also a burst dose of clonidine in the adhesive layer. The presence of the burst doses provides an immediate-release dose of clonidine which promotes rapid systemic levels of the drug. 

Transdermal patches are marketed worldwide with the drug substances glycerole trinitrate, estradiol, testosterone, clonidine, scopolamine, fentanyl and nicotine, respectively. The patch has to remain for up to one week at the appropiate body site. In this case the drug amount in the reservoir is rather high. As liquid crystalline vehicles with lamellar microstructure have... 

Clonidine (Catapres) is an alpha-2 adrenergic agonist, which thereby functions as a presynaptic irdiibitor of norepinephrine release. It is usually used to treat hypertension (like the beta blockers) but has been used to treat amciety disorders with some success. It is also used to treat opiate withdrawal. A typical starting dose is 0.1 mg two to three times daily (see figure 16-C). It is also available as a transdermal patch. 

Ingestion is the most common route of both accidental and intentional exposures to clonidine. Toxicity may also occur via dermal exposure from transdermal patches. 

Side effects of clonidine therapy include dry mouth, drowsiness, sedation, and constipation. Abrupt discontinuation of therapy may result in a withdrawal syndrome manifested as restless and headache in addition to significant rebound hypertension. Withdrawal can be avoided by tapering therapy over 2-4 days. The incidence of a local dermatitis or an extended dermal reaction with use of the transdermal patch is 15-20%. 

As little as 0.1 mg of clonidine has produced toxicity in children determination of adult toxicity is based on observation as there is no milligram per kilogram toxic dose established. Clonidine levels are not clinically useful. Toxicity can result from ingestion of used clonidine transdermal patches as residual clonidine remains after full therapeutic use. Symptoms generally begin within 30-90 min and include hypotension, central nervous system depression, bradycardia, and... 

A small double-blind, placebo-controlled crossover study in seven children and two adults with autistic disorder and hyperarousal behavior found significant improvement relative to placebo with 0.5 mg/kg/day transdermal clonidine on the CGI scale. The primary adverse effects were fatigue and sedation (although it was stated that these declined over the course of the 4-week treatment period) and skin irritation from the transdermal patch. Blood pressure was significantly reduced... 

Clonidine is a potent antihypertensive agent which is well absorbed from the GI tract (95%). The dmg has a relatively long half-life (6-20 h) and a modest clearance (13 L h ). The rationale for the development of transdermal clonidine was to reduce side-effects and to improve patient compliance. Catapres-TTS, a reservoir-type patch, reached the market in 1985 in a form designed to remain in place and to deliver dmg for 7 days. Dose titration was possible via the use of systems of different active areas (3.5, 7.0, and 10.5 cm2). The control of dmg delivery over 7 days is impressive, and avoids the peaks and valleys of conventional (twice-a-day) oral administration (Figure 8.7). However, this system has not achieved as wide a success as first seemed likely because of skin sensitization. Clonidine itself, when administered transdermally on a chronic, repetitive basis, induces in a significant fraction of patients a classic immunologic skin reaction, and this has severely attenuated its use. 

Transdermal administration can avoid first-pass metabolism as well as provide a large surface area for continuous-controlled administration of drugs with short biological half-lives and narrow therapeutical indices. The route has been used for nitroglycerin ointments, and transdermal therapeutical systems (patches) have been developed for scopolamine, nitroglycerin, clonidine, estradiol, and nicotine. 

The popular Transdermal Scop patches are widely used by travelers who experience motion sickness, and contain 1.5 mg of scopolamine solubilized to approximately 100 mg/ml in mineral oil, and deliver 1.0 mg over three days. Catapres -TTS patches contain 2.5-7.5 mg of clonidine solubilized in mineral oil, and deliver 0.1-0.3 mg/day for seven days. Vivelle-DOT patches contain 0.39-1.6 mg of estradiol solubilized in... 

Transdermal clonidine formulated in adhesive skin patches has been used for long-term treatment with... 

A 47-year-old woman was given transdermal, oral, and intravenous clonidine at different times, separated by several months. The patches were withdrawn after 2 months because of pruritic erythematous vesiculation at the site of application. Oral clonidine (0.3 mg/day) had to be withdrawn when a generalized maculopapular rash appeared on the third day, and was promptly exacerbated by each dose. Intravenous clonidine 0.150 mg was followed within 30 minutes by a severe, generalized, maculopapular reaction requiring systemic steroids and antihistamines. 

The authors interpreted these reactions as being allergic. A patch test was very positive to the commercial formulation. Clonidine is a weak sensitizer, but occlusion and prolonged skin contact during transdermal application can cause delayed hypersensitivity. 

As shown in Table 4, sophisticated adhesive patches for transdermal delivery of scopolamine (motion sickness), nitroglycerine (anginal symptoms), clonidine (regulation... 

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