From the FDA Drug Label
The safety and efficacy of oxybutynin chloride administration have been demonstrated for pediatric patients 5 years of age and older (see DOSAGE AND ADMINISTRATION). At total daily doses ranging from 5 mg to 15 mg, treatment with oxybutynin chloride tablets was associated with an increase from baseline in mean urine volume per catheterization from 122 mL to 145 mL, an increase from baseline in mean urine volume after morning awakening from 148 mL to 168 mL, and an increase from baseline in the mean percentage of catheterizations without a leaking episode from 43% to 61%. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
The recommended dosing for oxybutynin in treating overactive bladder is:
- For pediatric patients 5 years of age and older: 5 mg to 15 mg per day
- For elderly patients: start at the low end of the dosing range, usually 2.5 mg given 2 or 3 times a day 1 Key points:
- The dose range for pediatric patients is 5 mg to 15 mg per day
- Elderly patients should start at a lower dose due to potential decreased hepatic, renal, or cardiac function.
- The dosing for oxybutynin should be cautious and individualized.
From the Research
The recommended dosing for oxybutynin in treating overactive bladder typically starts at 5 mg taken orally two to three times daily, with a maximum daily dose of 30 mg. For immediate-release tablets, the usual starting dose is 5 mg two to three times daily, which can be adjusted based on patient response. Extended-release formulations are dosed once daily, usually starting at 5-10 mg and can be increased to 30 mg daily if needed 2. Transdermal patches (Oxytrol) are applied twice weekly (every 3-4 days) and deliver 3.9 mg per day. Oxybutynin gel (Gelnique) is applied once daily as a 1 gram dose (containing 10% oxybutynin) to the abdomen, upper arms, shoulders, or thighs. Dosing should be individualized based on patient response and tolerability, with lower starting doses recommended for elderly patients. Oxybutynin works by blocking muscarinic receptors in the bladder, reducing involuntary detrusor muscle contractions and increasing bladder capacity. Common side effects include dry mouth, constipation, blurred vision, and drowsiness, which may limit dose escalation in some patients. Some key points to consider when prescribing oxybutynin include:
- The extended-release formulation may have a better tolerability profile compared to the immediate-release formulation 2
- Oxybutynin may have a similar efficacy to tolterodine, but with a different side effect profile 3
- The dosage of oxybutynin can be adjusted based on patient response, with a maximum daily dose of 30 mg 2 It's also important to note that oxybutynin has been shown to be effective in improving health-related quality of life in patients with overactive bladder 2. Overall, oxybutynin is a viable treatment option for overactive bladder, and its dosing should be individualized based on patient response and tolerability.