If first-line therapies are not effective, anticholinergic medications may be suggested. They work by inhibiting involuntuary detrusor muscle spasms. A wide variety of medications are available, each with its own potential risks and benefits. Side effects are the biggest drawback of this type of medication, including: dry mouth, constipation, blurred vision and drowsiness.
- Oxybutynin (Ditropan, Ditropan XL) was one of the first medications used with solid success.
- Tolteradine (Detrol, Detrol LA) has a similar method of action and effectiveness but causes fewer side effects.
- Trospium chloride (Sanctura)
- Solifenacin (Vesicare)
- Darifenacin (Enablex)
- Oxybutynin patch (Oxytrol)
- Fesoterodine (Toviaz).
Side Effects & Warnings
Extended release formulations, such as Ditropan XL, have been found to have lower rates of dry mouth. The AUA suggests the use of the oxybutynin transdermal patch (Oxytrol) for patients to further reduce the risk of dry mouth.
If side effects are burdensome and/or the patient has received no benefit, they encourage trying a different medication and/or adjusting the dosage to reduce side effects. Darifenacin appears to cause fewer cognitive effects. Trospium may be more suitable for patients who are being treated with cytochrome P-450 medications.
Frail, elderly patients have a higher adverse event profile with these medications thus they should used with great caution. Dry mouth and constipation may be more intense. Some have experienced impaired thermoregulation that can cause dangerous core temperature elevation. Confusion and diminished cognitive function have also been well documented and risk of cognitive impairment appears to increase with the more anticholinergic medications taken.
Anti-muscarinics should not be used in patients with narrow angle glaucoma unless approved by the treating ophthalmologist.
Extreme caution is urged for patients with impaired gastric emptying or a history of urinary retention.