Kentera 3.9 mg / 24 hours transdermal patch

Each transdermal patch contains 36 mg of oxybutynin. The area of the patch is 39 cm2, releasing a nominal 3.9 mg of oxybutynin per 24 hours.

Symptomatic treatment of urge incontinence and/or increased urinary frequency and urgency as may occur in adult patients with unstable bladder.

The patch should be applied to dry, intact skin on the abdomen, hip, or buttock immediately after removal from the protective sachet. A new application site should be selected with each new patch to avoid reapplication to the same site within 7 days.

The recommended dose is one 3.9 mg transdermal patch applied twice weekly (every 3 to 4 days).

There is no experience in children.

Hypersensitivity to the active substance or to any of the excipients.

Kentera is contraindicated in patients with urinary retention, severe gastro-intestinal condition, myasthenia gravis or narrow-angle glaucoma and in patients who are at risk for these conditions.

Kentera should be used with caution in patients with hepatic or renal impairment. The use of Kentera in patients with hepatic impairment should be carefully monitored. Other causes of frequent urination (heart failure or renal disease) should be assessed before treatment with Kentera. If urinary tract infection is present, an appropriate antibacterial therapy should be started.

Urinary retention: Anticholinergic products should be administered with caution to patients with clinically significant bladder outflow obstruction because of the risk of urinary retention.

Kentera should be used with caution in elderly patients, who may be more sensitive to the effects of centrally acting anticholinergics and exhibit differences in pharmacokinetics.

Oral administration of oxybutynin may warrant the following cautionary statements, but these events were not observed during clinical trials with Kentera:

Gastrointestinal disorders: Anticholinergic medicinal products may decrease gastrointestinal motility and should be used with caution in patients with gastrointestinal obstructive disorders because of the risk of gastric retention. Also in conditions such as ulcerative colitis, and intestinal atony. Anticholinergic medicinal products should be used with caution in patients who have hiatus hernia/gastro-oesophageal reflux and/or who are concurrently taking medicinal products (such as bisphosphonates) that can cause or exacerbate oesophagitis.

Anticholinergic medicinal products should be used with caution in patients who have autonomic neuropathy, cognitive impairment or Parkinson's disease

Patients should be informed that heat prostration (fever and heat stroke due to decreased sweating) can occur when anticholinergics such as oxybutynin are used in a hot environment.

Oxybutynin may exacerbate the symptoms of hyperthyroidism, coronary heart disease, congestive heart failure, cardiac arrhythmias, tachycardia, hypertension and prostatic hypertrophy

Oxybutynin may lead to suppressed salivary secretions which could result in dental caries, parodontosis or oral candidiasis.

The concomitant use of oxybutynin with other anticholinergic medicinal products or with other agents that compete for CYP3A4 enzyme metabolism may increase the frequency or severity of dry mouth, constipation, and drowsiness.

Anticholinergic agents may potentially alter the absorption of some concomitantly administered medicinal products due to anticholinergic effects on gastrointestinal motility. As oxybutynin is metabolised by cytochrome P 450 isoenzyme CYP 3A4, interactions with medicinal products that inhibit this isoenzyme cannot be ruled out. This should be borne in mind when using azole antifungals (e.g. ketoconasole) or macrolide antibiotics (e.g. erythromycin) concurrently with oxybutynin.

The anticholinergic activity of oxybutynin is increased by concurrent use of other anticholinergics or medicinal products with anticholinergic activity, such as amantadine and other anticholinergic antiparkinsonian medicinal products (e.g. biperiden, levodopa), antihistamines, antipsychotics (e.g. phenothiazines, butyrophenones, clozapine), quinidine, tricyclic antidepressants, atropine and related compounds like atropinic antispasmodics, dipyridamole.

Patients should be informed that alcohol may enhance the drowsiness caused by anticholinergic agents such as oxybutynin.

Oxybutynin may antagonize prokinetic therapies.

The most commonly reported adverse drug reactions were application site reactions, occurring in 23.1% of patients. Other commonly occurring adverse drug reactions reported were dry mouth (8.6%), constipation (3.9%), diarrhoea (3.2%), headache (3.0%), dizziness (2.3%) and blurred vision (2.3%).

Adverse reactions known to be associated with anticholinergic therapy, but not observed with Kentera during clinical studies are anorexia, vomiting, reflux oesophagitis, decreased sweating, heat stroke, decreased lacrimation, mydriasis, tachycardia, arrhythmia, disorientation, poor ability to concentrate, fatigue, nightmares, restlessness, convulsion, intraocular hypertension and induction of glaucoma, confusion, anxiety, paranoia, hallucinations, photosensitivity, erectile dysfunction.

The adverse reactions reported below are classified according to frequency of occurrence as follows:

• Very common ( 1/10)

• Common ( 1/100 to < 1/10)

• Uncommon ( 1/1,000 to < 1/100) 

Orion Pharma (UK) Limited

POM – Prescription Only Medicine

18 October 2010