Generic Equivalent of Myrbetriq
Mirabegron is the generic name for Myrbetriq—they are the same medication, with "mirabegron" being the active pharmaceutical ingredient and "Myrbetriq" being the brand name marketed by Astellas Pharma. 1
Medication Identity
- Mirabegron extended-release tablets are available in 25 mg and 50 mg oral formulations, identical to the branded Myrbetriq product 1
- The chemical name is 2-(2-Aminothiazol-4-yl)-N-(4-(2-(2R)-hydroxy-2-phenylethylamino)ethyl)phenyl)acetamide with molecular formula C21H24N4O2S 1
- Each tablet contains the same inactive ingredients regardless of whether dispensed as generic or brand: polyethylene oxide, polyethylene glycol, magnesium stearate, hypromellose, and iron oxides 1
Clinical Mechanism and Use
- Mirabegron functions as a β3-adrenergic receptor agonist that relaxes detrusor smooth muscle during bladder storage, increasing bladder capacity for treatment of overactive bladder 1, 2
- The American Urological Association and European Association of Urology guidelines both support mirabegron as an effective treatment option for overactive bladder symptoms with strong evidence 3, 4
Standard Dosing
- Start with 25 mg orally once daily, which can be increased to 50 mg once daily after 4-8 weeks if needed 3
- Take with food to reduce potential exposure-related risks such as increased heart rate 1
- The 25 mg dose is particularly appropriate for older patients (≥65 years) with multiple comorbidities, patients with severe renal impairment, or those with moderate hepatic impairment 3, 1
Key Safety Considerations
- Monitor blood pressure periodically, especially during initial treatment, as mirabegron can cause dose-dependent increases in systolic pressure 3, 5
- The medication is contraindicated in severe uncontrolled hypertension 5
- Most common adverse events include hypertension, urinary tract infections, headache, and nasopharyngitis 3, 6
- Mirabegron has significantly lower rates of dry mouth (2.8% at 12 months) compared to antimuscarinic alternatives like tolterodine (8.6%), making it advantageous for patients who cannot tolerate anticholinergic side effects 2, 6