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BetmigaTM (mirabegron) is indicated for symptomatic treatment of urgency, increased micturition frequency and/or urgency incontinence as may occur in adult patients with overactive bladder (OAB) syndrome and for treatment of neurogenic detrusor overactivity (NDO) in paediatric patients aged 3 to <18 years.1
Betmiga is available as prolonged release tablets to be taken with liquids, swallowed whole, and not to be chewed, divided or crushed. It may be taken with or without food. ‘Prolonged release’ means that mirabegron is released slowly from the tablet over a few hours. Betmiga is taken once a day at a recommended dose of 50 mg. In children, the dose depends on the patient’s body weight. In patients who have reduced kidney or liver function, the prescriber may need to prescribe a lower dose (25 mg).1
Betmiga can generally be used in patients with a history of heart disease or stroke for overactive bladder (OAB) treatment. Betmiga has demonstrated a cardiovascular safety profile like antimuscarinics and placebo in clinical trials and real-world data.2-8 However, its use in patients with heart failure requires careful consideration due to uncertainty regarding its efficacy and safety in this specific population.1
Betmiga is contraindicated in patients with severe uncontrolled hypertension defined as systolic blood pressure ≥ 180 mm Hg and/or diastolic blood pressure ≥ 110 mm Hg.1
Betmiga generally demonstrates a favourable cognitive safety profile. Clinical trials in elderly patients with OAB and those with central nervous system (CNS) disorders, including cerebrovascular accident (CVA) and Parkinson's disease, show that mirabegron does not adversely affect cognitive function.9-12 Notably, a pilot study in older individuals with spinal cord injury (SCI) indicated that switching from anticholinergic agents to mirabegron led to significant improvements in memory and executive function.13
No information is available on how to discontinue treatment with Betmiga, this would be a clinical decision. However, the following information may be useful. Mirabegron is transported and metabolised through multiple pathways. Mirabegron is a substrate for several enzymes including CYP2D6. In healthy volunteers, the inhibitory potency of mirabegron towards CYP2D6 is moderate and the CYP2D6 activity recovers within 15 days after discontinuation of mirabegron. Overall clearance (CLtot) from plasma is approximately 57 L /h. Renal clearance is approximately 13 L /h, which corresponds to nearly 25 % of CLtot. Mirabegron’s terminal elimination half-life is approximately 50 hours.1 The plasma concentration of mirabegron is expected to be below clinically relevant levels within four to five half-lives, or approximately 8 to 10 days after discontinuation.14
The effect of Betmiga on human fertility has not been established. There is a limited amount of data from the use of mirabegron in pregnant women. The use of mirabegron in pregnancy should be avoided unless the benefit to the patient outweighs the risk to the foetus. Genotoxicity and carcinogenicity studies have shown no genotoxic or carcinogenic potential in vivo.1
Betmiga is indicated for the treatment of overactive bladder (OAB) in adults (≥18 years) only. Betmiga is not approved for the treatment of OAB in paediatric patients. However, Betmiga is indicated in children and adolescents (3 to <18 years) for the treatment of neurogenic detrusor overactivity (NDO), where dosing is based on body weight.1
Betmiga tablets should be taken once daily with liquids, with or without food and swallowed whole. Tablets should not be chewed, divided or crushed1. No pharmacokinetic data are available regarding the absorption of the active substance mirabegron after crushing. The Oral Controlled Absorption System (OCAS®), developed by Astellas Pharma, Inc., is a prolonged-release delivery system15. It incorporates gel-forming and gel-enhancing agents to promote a constant drug release, independent of environmental food or fluid. Rapid and complete gelation allows the release of drug from the tablets over an extended period, for a more consistent absorption rate in the gastrointestinal tract compared to immediate-release formulations, even under fasting conditions. The tablets must not be crushed, as the prolonged release mechanism of the mirabegron tablets is of the OCAS type and splitting or crushing the tablets would compromise the prolonged release mechanism.
The recommended dose of Betmiga in adults (including elderly) is 50 mg once daily. Astellas has not conducted trials to assess the safety and/or efficacy of alternative dosing regimens such as twice daily, using two tablets as one dose, or as-needed regimens. In children or adolescents (3 to <18 years) with NDO, the recommended starting dose of prolonged release tablets is 25 mg once daily with food. If needed, the dose may be increased to a maximum dose of 50 mg once daily with food after 4 to 8 weeks. During long-term therapy, patients should be periodically evaluated for treatment continuation and for potential dose adjustment, at least annually or more frequently if indicated.1
For any medical enquiries, please email medinfo.est-m@astellas.com or call +353-1-467-1555
References
1. BETMIGA (mirabegron) prolonged-release tablets. Summary of Product Characteristics ; 2. White, WB. et al. J. Am Soc Hypertens. 2018; 12(11):768-778; 3. Lockefeer, A. et al. Eur Uol Focus. 2026;18:S2405-4569(26); 4. Hoffman V. et al. Drug Saf. 2021;44(8):899-915; 5. Nitti VW, et al. Int J Clin Pract. 2014;68(8):972–85; 6. Chapple, CR. et al. Eur. Urol. 2020;77(1):119–128; 7. Katoh T, et al. Int J Urol. 2016;23(12):1009–15; 8. Katoh T, et al. Low Urin Tract Symptoms. 2021;13(1):98–107; 9. Griebling, TL. et al. BMC Geriatr. 2020;20(1):109; 10. Chen, S-F. et al. J Formos Med Assoc. 2022;121(10):2101-2108; 11. Vasudeva, P. et al. Neurourol Urodyn. 2021; 40(8):2041-2047; 12. Anis, O. et al. Curr Urol Rep. 2025;26(1):77; 13. Trbovich, M. et al. Spinal Cord Ser Cases. 2021;7(1):50; 14. Jericho H, Valerie G. National Center for Biotechnology Information, U .S. National Library of Medicine. StatPearls. Available at: https: / /www .ncbi .nlm .nih .gov /books /NBK554498 / #:~:text=Even %20further %2C %2094 %20to %2097 ,thus %20will %20be %20considered %20eliminated. Accessed 11JUN2026; 15. Fix, J. et al. Controlled-Release Oral Delivery Systems. 2000;752:14-24.
Adverse events should be reported. For Ireland, Healthcare professionals are asked to report any suspected adverse reactions via: HPRA Pharmacovigilance, Website: www.hpra.ie or Astellas Pharma Co. Ltd. Tel:+353 1 467 1555, E-mail: irishdrugsafety@astellas.com.
MAT-IE-BET-2026-00009 Sep 2026