From the Guidelines
The recommended dose of oxybutynin for overactive bladder is 0.2 mg/kg orally given 3 times daily, as indicated in the most recent and highest quality study 1. This dose is specifically recommended for patients with detrusor overactivity, including those with neurogenic bladder.
- The medication 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.
- It is essential to individualize the dose based on patient response and tolerability, and to monitor for potential side effects.
- The study 1 provides the most recent and highest quality evidence for the recommended dose of oxybutynin, and should be prioritized in clinical decision-making.
- Other studies, such as 1 and 1, provide additional information on the use of oxybutynin in different patient populations, but the dose recommended in 1 is the most relevant and up-to-date.
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 dose of oxybutynin for overactive bladder is 5-15 mg per day, given in divided doses. For pediatric patients 5 years of age and older, the dose range is the same. For elderly patients, a lower initial starting dose of 2.5 mg given 2 or 3 times a day is recommended due to the potential for prolonged elimination half-life 2.
From the Research
Oxybutynin Dose for Overactive Bladder
The recommended dose of oxybutynin for overactive bladder can vary depending on the specific formulation and the patient's response to treatment.
- The initial dose of oxybutynin can be 2.5 mg twice daily, increasing to 5 mg twice daily after 2 weeks of treatment 3.
- A controlled release tablet formulation of oxybutynin can be administered at a dose of 10 mg once daily, which has been shown to be as effective and well-tolerated as the conventional formulation 4.
- A low-dose regimen of oxybutynin, starting at 2.5 mg three times daily, can be effective for the treatment of urge incontinence with fewer side effects 5.
- Oxybutynin can also be administered at a dose of 5 mg three times daily, which has been shown to be effective in reducing symptoms of overactive bladder 6.
- A long-term prospective randomized study compared two different regimens of oxybutynin, starting with either 2.5 mg twice daily or 5 mg nocte, and increasing up to 5 mg three times daily over a period of 6 weeks 7.
Factors Affecting Dose
The dose of oxybutynin may need to be adjusted based on the patient's response to treatment and the presence of any side effects.
- Patients who experience little or no symptomatic relief and no side effects may be given a higher dose of oxybutynin 5.
- The incidence of adverse events, such as dry mouth, can be higher with oxybutynin compared to other medications, such as tolterodine 3, 6.
- Patient compliance and treatment efficacy can be assessed over the long-term, and adjustments to the dose can be made as needed 7.