Can oxybutynin and Myrbetriq (mirabegron) be taken together?

From the Guidelines

Yes, oxybutynin and Myrbetriq (mirabegron) can be taken together, as combination therapy with an anti-muscarinic and β3-adrenoceptor agonist is considered a viable option for patients refractory to monotherapy with either anti-muscarinics or β3-adrenoceptor agonists 1.

Key Considerations

• The combination of solifenacin and mirabegron has been studied extensively, demonstrating improved efficacy without significant effects on the safety profile compared to monotherapy 1.
• While there is limited literature on the combination of oxybutynin and mirabegron, the mechanism of action of these two medications suggests that they can be used together, as they target different pathways in the treatment of overactive bladder.
• Adverse events, including dry mouth, constipation, and dyspepsia, may be slightly increased in combination therapy groups compared to monotherapies 1.
• Clinicians should consider the individual patient's response to therapy and adjust treatment accordingly, as some patients may experience better symptom control and/or a more acceptable adverse drug event profile with combination therapy 1.

Dosage and Administration

• The typical dosage of oxybutynin is 5-10 mg orally twice a day, while the typical dosage of mirabegron is 25-50 mg orally once a day.
• Patients should be monitored for adverse events and dosage adjustments made as necessary to achieve a balance between efficacy and tolerability.

From the Research

Combination Therapy for Overactive Bladder

• The combination of mirabegron and solifenacin has been shown to be effective in treating overactive bladder (OAB) symptoms, with significant improvements in micturition frequency, incontinence episodes, and urgency episodes compared to solifenacin monotherapy 2, 3.
• Studies have also demonstrated that mirabegron can be used in combination with other antimuscarinics, such as oxybutynin, although the specific combination of mirabegron and oxybutynin has not been directly studied in the provided evidence.
• The efficacy and safety of combination therapy with mirabegron and antimuscarinics have been evaluated in several studies, with results suggesting that combination therapy can provide improved efficacy and similar tolerability compared to monotherapy 2, 4, 3.

Tolerability and Safety

• Mirabegron has been shown to have a more favorable tolerability profile compared to antimuscarinics, with a lower incidence of anticholinergic side effects such as dry mouth and constipation 5, 6.
• The combination of mirabegron and solifenacin has been found to be well tolerated, with no important additional safety findings compared to monotherapy or placebo 3.
• However, the incidence of constipation was slightly increased with combination therapy, and the safety profile of combination therapy with mirabegron and oxybutynin is not directly addressed in the provided evidence.

Clinical Implications

• The use of mirabegron in combination with antimuscarinics, such as oxybutynin, may be considered as a treatment option for patients with OAB, although further studies are needed to directly evaluate the efficacy and safety of this specific combination.
• Healthcare providers should carefully consider the potential benefits and risks of combination therapy and monitor patients for any adverse effects, particularly anticholinergic side effects 2, 5, 4, 6, 3.