Oxytrol Drug Information

OXYTROL is a muscarinic antagonist indicated for the treatment of overactive bladder in men with symptoms of urge urinary incontinence, urgency, and frequency.

OXYTROL 3.9 mg/day should be applied to dry, intact skin on the abdomen, hip, or buttock twice weekly (every 3 or 4 days). A new application site should be selected with each new transdermal system to avoid re-application to the same site within 7 days. Do not divide or cut the transdermal system into pieces.

Do not use if the transdermal system is damaged. Apply OXYTROL transdermal system twice weekly (every 3 to 4 days) to dry, intact skin on the abdomen, hip, or buttocks.

Clinical Trials 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 clinical practice. The safety of OXYTROL was evaluated in a total of 417 patients who participated in two clinical efficacy and safety studies and an open-label extension. Additional safety information was collected in earlier phase trials.

In the two pivotal studies, a total of 246 patients received OXYTROL during the 12-week treatment periods. No deaths were reported during treatment. No serious adverse events related to treatment were reported.

Adverse reactions reported in the pivotal trials are summarized in Tables 1 and 2 below. Most adverse reactions were described as mild or moderate in intensity. Most of these discontinuations were due to application site reaction.

In the two pivotal studies, no patient discontinued OXYTROL treatment due to dry mouth. In the open-label extension, the most common treatment-related adverse reactions were: application site pruritus, application site erythema, and dry mouth.

Postmarketing Experience

The following adverse reactions have been identified during post approval use of OXYTROL. 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. Nervous System Disorders: Memory impairment, dizziness, somnolence, confusion Psychiatric Disorders: Delirium, hallucinations

Other Anticholinergics

The concomitant use of OXYTROL with other anticholinergic drugs, or with other agents that produce dry mouth, constipation, somnolence, and/or other anticholinergic-like effects may increase the frequency and/or severity of such effects. Anticholinergic agents may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility.

Cytochrome P450 Inhibitors

Pharmacokinetic studies have not been performed with patients concomitantly receiving cytochrome P450 enzyme inhibitors, such as antimycotic agents (e.g., ketoconazole, itraconazole, and miconazole) or macrolide antibiotics (e.g., erythromycin and clarithromycin).

Pregnancy Risk Summary There are no studies with topical or oral oxybutynin use in pregnant women to inform a drug associated risk for birth defects or miscarriage. No adverse developmental outcomes were observed in animal reproduction studies when oxybutynin chloride was administered to pregnant rats and rabbits during organogenesis at approximately 50 and 1 times, respectively, the maximum human dose based on body surface area ( see Data ). In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20% respectively.

Data A n i m al Da t a Subcutaneous administration of oxybutynin chloride to rats at doses up to 25 mg/kg (approximately 50 times the human exposure based on surface area) and to rabbits at doses up to 0.4 mg/kg (approximately 1 times the human exposure based on body surface area) throughout the period of organogenesis revealed no evidence of harm to the fetus.

Pediatric Use The safety and efficacy of OXYTROL in pediatric patients have not been established.

The use of OXYTROL is contraindicated in the following conditions: Urinary retention Gastric retention Uncontrolled narrow-angle glaucoma Known serious hypersensitivity reaction to OXYTROL, oxybutynin, or to any of the components of OXYTROL.

The plasma concentration of oxybutynin declines within 1 to 2 hours after removal of transdermal system(s). Patients should be monitored until symptoms resolve. Overdosage with oxybutynin has been associated with anticholinergic effects including CNS excitation, flushing, fever, dehydration, cardiac arrhythmia, vomiting, and urinary retention.

Ingestion of 100 mg oral oxybutynin chloride in association with alcohol has been reported in a 13 year old boy who experienced memory loss, and in a 34 year old woman who developed stupor, followed by disorientation and agitation on awakening, dilated pupils, dry skin, cardiac arrhythmia, and retention of urine. Both patients recovered fully with treatment directed at their symptoms.