Mirabegron

Systematic (IUPAC) name
2-(2-Amino-1,3-thiazol-4-yl)-N-[4-(2-{[(2R)-2-hydroxy-2-phenylethyl]amino}ethyl)phenyl]acetamide
Clinical data
Trade names	Myrbetriq (US), Betanis (JP), Betmiga (EU, RU)
Licence data	EMA:Link, US FDA:link
Pregnancy category	US: C (Risk not ruled out)
Legal status	UK: POM (Prescription only) US: ℞-only ℞ (Prescription only)
Routes of administration	Oral (tablets)
Pharmacokinetic data
Bioavailability	29–35%
Protein binding	71%
Metabolism	Hepatic via (direct) glucuronidation, amide hydrolysis, and minimal oxidative metabolism in vivo by CYP2D6 and CYP3A4. Some involvement of butylcholinesterase
Biological half-life	50 hours
Excretion	Urine (55%), faeces (34%)
Identifiers
CAS Number	223673-61-8
ATC code	G04BD12 (WHO)
PubChem	CID: 9865528
ChemSpider	8041219
Synonyms	YM-178
Chemical data
Formula	C21H24N4O2S
Molecular mass	396.506 g/mol
SMILES O=C(Nc1ccc(cc1)CCNC[C@H](O)c2ccccc2)Cc3nc(sc3)N
InChI InChI=1S/C21H24N4O2S/c22-21-25-18(14-28-21)12-20(27)24-17-8-6-15(7-9-17)10-11-23-13-19(26)16-4-2-1-3-5-16/h1-9,14,19,23,26H,10-13H2,(H2,22,25)(H,24,27)/t19-/m0/s1 Key:PBAPPPCECJKMCM-IBGZPJMESA-N

Mirabegron (trade name Myrbetriq meer-BET-trick in the US and Betmiga in Europe) is a drug for the treatment of overactive bladder. It was developed by Astellas Pharma and was approved in the United States in July 2012.

Mirabegron activates the β₃ adrenergic receptor in the detrusor muscle in the bladder, which leads to muscle relaxation and an increase in bladder capacity.

Medical uses

Its primary use is in the treatment of overactive bladder.

Mirabegron has also recently been shown to activate brown fat and increase metabolism. In a small study of 15 healthy, lean men, Mirabegron was shown to increase basal heart rate, metabolic rate and blood pressure which are signs of cardiovascular stimulation.

Recently, mirabegron was shown to relax in vitro human and rabbit prostate smooth muscle through activation of β₃ adrenoceptor. The same group also showed that mirabegron promotes smooth muscle relaxation by α₁ adrenergic receptor blockade.

Adverse effects

Adverse effects by incidence:

Very common (>10% incidence) adverse effects include:

• Elevated blood pressure

Common (1–10% incidence) adverse effects include:

• Dry mouth
• Nasopharyngitis
• Urinary tract infection (UTI)
• Headache
• Influenza
• Constipation
• Dizziness
• Joint pain
• Cystitis
• Back pain
• Upper respiratory tract infection (URTI)
• Sinusitis
• Diarrhea
• High heart rate
• Fatigue
• Abdominal pain
• Neoplasms (cancers)

Rare (<1% incidence) adverse effects include:

• Palpitations
• Blurred vision
• Glaucoma
• Indigestion
• Gastritis
• Abdominal distension
• Rhinitis
• Elevations in liver enzymes (GGTP, AST, ALT and LDH)
• Renal and urinary disorders (e.g., nephrolithiasis, bladder pain)
• Reproductive system disorders (e.g., vulvovaginal pruritis, vaginal infection)
• Skin and subcutaneous tissue disorders (e.g., urticaria, leukocytoclastic vasculitis, rash, pruritus, purpura, lip edema)
• Stevens–Johnson syndrome associated with increased serum ALT, AST and bilirubin
• Urinary retention