From the Guidelines
Oxybutynin is not the ideal choice for managing bladder pain and spasms in men with enlarged prostate or prostate cancer due to the potential risk of worsening urinary retention. When considering the treatment of bladder spasms and pain, especially in the context of enlarged prostate or prostate cancer, it's crucial to prioritize medications that do not exacerbate urinary retention. Oxybutynin, as an antimuscarinic medication, is indicated for detrusor overactivity in patients with neurogenic bladder, as noted in a study published in The Journal of Urology 1. However, its use in men with significant prostate enlargement or prostate cancer requires caution because it can relax the bladder muscle, potentially worsening urinary retention.
The typical use of oxybutynin involves a dose of 0.2 mg/kg given orally three times daily for subjects with a hostile bladder on urodynamic evaluation, as per the study 1. Yet, for men with prostate issues, combining oxybutynin with alpha-blockers (like tamsulosin) or 5-alpha reductase inhibitors (like finasteride) might be necessary to address prostate-related outflow obstruction. Common side effects of oxybutynin include dry mouth, constipation, blurred vision, and confusion, particularly in older adults.
Given the potential risks and the specific context of enlarged prostate or prostate cancer, alternative medications such as mirabegron might be more suitable for some patients, especially if they cannot tolerate oxybutynin. Ultimately, any decision to prescribe bladder medication should follow a thorough urological evaluation to ensure the chosen treatment does not worsen underlying conditions. Men with prostate cancer should discuss oxybutynin with their oncologist, considering the treatment context is crucial.
From the FDA Drug Label
Oxybutynin chloride is indicated for the relief of symptoms of bladder instability associated with voiding in patients with uninhibited neurogenic or reflex neurogenic bladder (i.e., urgency, frequency, urinary leakage, urge incontinence, dysuria). Oxybutynin chloride exerts a direct antispasmodic effect on smooth muscle and inhibits the muscarinic action of acetylcholine on smooth muscle. Oxybutynin chloride relaxes bladder smooth muscle In patients with conditions characterized by involuntary bladder contractions, cystometric studies have demonstrated that oxybutynin chloride increases bladder (vesical) capacity, diminishes the frequency of uninhibited contractions of the detrusor muscle, and delays the initial desire to void
Oxybutynin may be beneficial for bladder pain spasm as it relaxes bladder smooth muscle and decreases urgency and frequency. However, the labels do not explicitly mention its use in patients with enlarged prostate and prostate cancer. Therefore, its effectiveness in this specific population is unclear. 2 2
From the Research
Oxybutynin for Bladder Pain and Spasm
- Oxybutynin is a muscarinic receptor antagonist used to treat overactive bladder (OAB) symptoms, including urinary urgency, frequency, and incontinence 3, 4.
- The medication has been shown to be effective in reducing OAB symptoms in adults, including those with enlarged prostate and prostate conditions 5.
- A study found that oxybutynin transdermal system improved health-related quality of life and reduced symptoms of OAB in men with prostate conditions, including benign prostatic hyperplasia (BPH) 5.
Efficacy in Men with Prostate Conditions
- Oxybutynin has been found to be effective in treating OAB symptoms in men with prostate conditions, including BPH and prostate cancer 5, 6.
- A study found that sublingual oxybutynin reduced postoperative pain related to indwelling bladder catheter after radical retropubic prostatectomy, a common treatment for prostate cancer 6.
Safety and Tolerability
- Oxybutynin has been shown to be well-tolerated in most patients, with common side effects including dry mouth, constipation, and drowsiness 3, 7.
- However, oxybutynin may not be suitable for all patients, particularly the elderly, due to the risk of cognitive impairment and other anticholinergic side effects 7.