AlternativeBetmiga
Mirabegron
β3-adrenergic agonist
Non-anticholinergic OAB option — good for elderly or cognitive concerns.
Oral MR
First-line for
- OAB when antimuscarinics contraindicated or intolerable
- Add-on with solifenacin for refractory OAB
Mechanism
β3 agonism relaxes detrusor during storage phase without affecting voiding contraction.
"Mirabegron = mindful of blood pressure"
- Take BP before and 2 weeks after start
- Avoid if uncontrolled HTN (>180/110)
- No cognitive impairment vs antimuscarinics
Dosing
- Standard
- 50 mg OD (25 mg if renal/hepatic impairment)
Contraindications
- AbsoluteSevere uncontrolled hypertension (≥180/110)
- CautionEnd-stage renal disease, severe hepatic impairment
Side effects
- Hypertension
- Tachycardia
- UTI, headache
- Angio-oedema (rare)
Fetal & maternal notes
- • No adequate human data — avoid in pregnancy
Key interactions
Digoxin
Caution↑ digoxin levels — monitor
Metoprolol / propafenone
Caution↑ substrate levels via CYP2D6 inhibition
Clinical pearls
- 💡 Combine with solifenacin (SYNERGY trial) for stubborn OAB
- 💡 Avoid if BP not controlled
Content last reviewed: REPLACE_ME (e.g. 2026-07)
Spotted something out of date? See our disclaimer or use Report an Error above.