From the Guidelines
Converting from Detrol (tolterodine) to Ditropan (oxybutynin) should be done under medical supervision, with a typical conversion of 2 mg of Detrol daily to 5 mg of Ditropan two to three times daily, while being aware of the potential for more dry mouth and constipation with Ditropan due to its less selective anticholinergic effects 1. When switching, it's best to discontinue Detrol and start Ditropan the following day at the appropriate dose.
Key Considerations
- Patients should be informed about the differences in side effect profiles between Detrol and Ditropan, with Ditropan often causing more dry mouth and constipation 1.
- Ditropan is available in various formulations, including immediate-release tablets, extended-release tablets, and a transdermal patch, with the extended-release formulation potentially causing fewer side effects.
- Elderly patients typically require lower doses due to increased sensitivity to anticholinergic side effects 1.
Monitoring and Adjustments
- The conversion should be monitored for efficacy and side effects, with dosage adjustments made as needed.
- Clinicians should identify and manage conditions that may cause or worsen urinary incontinence, such as urinary tract infections, metabolic disorders, and impaired mental conditions 1.
Evidence-Based Decision
The decision to convert from Detrol to Ditropan should be based on the potential harms and benefits of each medication, with tolterodine causing fewer harms than oxybutynin, according to the American College of Physicians guideline 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Conversion from Tolterodine to Oxybutynin
- The conversion from Tolterodine (Detrol) to Oxybutynin (Ditropan) is based on the individual patient's response and tolerance to the medication 2.
- There is no direct conversion ratio between Tolterodine and Oxybutynin, as they have different pharmacokinetic profiles and mechanisms of action 3, 4.
- However, studies have shown that patients can be converted from immediate-release Oxybutynin to extended-release Oxybutynin, with similar efficacy and improved tolerability 5, 6.
- When converting from Tolterodine to Oxybutynin, the dosage of Oxybutynin can be started at 5-10 mg/day, with adjustments made based on the patient's response and tolerance 3, 4.
- It is essential to monitor the patient's response to the new medication and adjust the dosage as needed to achieve optimal efficacy and minimize side effects 2, 6.
Dosage and Administration
- Oxybutynin is available in immediate-release and extended-release formulations, with the extended-release formulation providing a more consistent and sustained release of the medication 4, 5.
- The dosage of Oxybutynin can be adjusted based on the patient's response and tolerance, with a maximum daily dose of 30 mg/day 3, 4.
- The medication should be taken orally, with or without food, and with a full glass of water 3, 4.
Side Effects and Tolerability
- The most common side effects of Oxybutynin include dry mouth, constipation, and dizziness 3, 4, 6.
- The incidence of side effects can be minimized by starting with a low dose and gradually increasing as needed and tolerated 2, 6.
- Patients should be monitored for signs of anticholinergic toxicity, such as confusion, hallucinations, and urinary retention 2, 4.