Products
Mirabegron is commercially available in the form of sustained-release film-coated tablets (Betmiga, USA: Myrbetriq). It was approved in the US and EU in 2012 and in many countries in 2014. Mirabegron was the first agent from the beta3 agonist group to be approved for the treatment of irritable bladder. It was originally intended to be developed as an antidiabetic agent.
Structure and properties
Mirabegron (C21H24N4O2S, Mr = 396.5 g/mol) is an aminothiazole acetamide. It exists as a white powder that is practically insoluble in water. The active ingredient is present in the drug as a pure -enantiomer.
Effects
Mirabegron (ATC G04BD12) is a selective beta3-adrenergic receptor agonist that exerts its effects during the urinary bladder. During this phase, the sympathetic portion of the autonomic nervous system is primarily active. It relaxes the bladder wall smooth muscle, increases bladder capacity and improves urine storage function. This results in relief of symptoms: mirabegron increases micturition volume and decreases micturition frequency. It has a long half-life of up to 50 hours. During which the urinary bladder is predominantly under the control of the parasympathetic nervous system (see also under parasympatholytics).
Indications
For symptomatic treatment of hyperactive bladder with symptoms of increased micturition frequency, imperative urination, and/or urge incontinence.
Dosage
According to the SmPC. Tablets are taken once daily, independent of meals.
Contraindications
- Hypersensitivity
For complete precautions, see the drug label.
Interactions
Mirabegron is a substrate of CYP3A4, CYP2D6, butyrylcholinesterase, UGT, P-glycoprotein, and organic cation transporters. Corresponding drug-drug interactions are possible.
Adverse effects
The most common possible adverse effects include hypertension, headache, urinary tract infection, and rapid heartbeat (tachycardia).