Mirabegron
A beta-3 agonist used for overactive bladder in adults and for neurogenic detrusor overactivity in children.
Drug card
- Class
- Beta-3 agonist
- How it works
- Activating beta-3 receptors to relax the bladder's detrusor muscle
- Used for
- Overactive bladder: urgency, frequency, urge incontinence
- Neurogenic detrusor overactivity in children
- Known for
- Raised blood pressure
- Fast heart rate (tachycardia)
- Urinary tract infection
- Its name
- -begron means a beta-3 agonist
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does mirabegron work?
Activates beta-3 receptors on the detrusor during the storage phase, raising bladder capacity. It has very little beta-1 or beta-2 activity at usual doses, though beta-1 stimulation appears at high doses. It moderately inhibits CYP2D6, and its half-life is about 50 hours.
Uses
What is mirabegron used for?
- Overactive bladder: urgency, frequency, urge incontinence
- Neurogenic detrusor overactivity in children
Side effects
Side effects of mirabegron
- Raised blood pressureKnown for
- Fast heart rate (tachycardia)Known for
- Urinary tract infectionKnown for
- Headache
- Colds and sore throat (nasopharyngitis)
- Constipation
- Diarrhea
- Nausea
- Joint pain
- Urinary retention, mainly with bladder outlet obstructionSerious
- Angioedema of the face, lips, tongue or larynxSerious
- Atrial fibrillationSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Check blood pressure regularly; not recommended in severe uncontrolled hypertension, and contraindicated in it in the EU.
- Take care with bladder outlet obstruction or alongside an antimuscarinic, because of urinary retention.
- As a moderate CYP2D6 inhibitor it raises levels of drugs such as metoprolol and desipramine; start digoxin low and monitor levels.
- Stop at once if angioedema involves the tongue, throat or larynx.
Good to know: Usually tried when antimuscarinics have not helped or do not suit. Vibegron, a newer beta-3 agonist, does not inhibit CYP2D6 and in a blood pressure study caused no clinically significant change.
Remember it
A way to remember it
FILL
- F
- Fast heart rate
- I
- Infections of the urinary tract
- L
- Larger bladder capacity, as the detrusor relaxes while filling
- L
- Look out for raised blood pressure with mirabegron
Written for biofideX
Its name
-begron means beta-3 agonist
Mirabegron activates beta-3 receptors and treats overactive bladder; vibegron shares the stem.
- Every drug name stem
Its class
Beta-3 agonists
They activate beta-3 adrenergic receptors in the detrusor muscle of the bladder wall. This relaxes the detrusor while the bladder fills, so it holds more urine with fewer unwanted contractions, easing urgency, frequency and urge incontinence. They work by a different route from the antimuscarinics, the other drug class for an overactive bladder.
Easily mixed up with antimuscarinics and short-acting beta-2 agonists.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Mirabegron extended-release tablets: label (DailyMed)
- Mirabegron (NCI Thesaurus)
- Mirabegron (NHS)
- Side effects of mirabegron (NHS)
- Mirabegron: EPAR (EMA)
- Vibegron tablets: label (DailyMed)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Reproductive and urinary health
Mirabegron is one of 9 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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