Mirabegron

Oral
Urinary incontinence, urgency and frequency

Haemodialysis patients: Contraindicated.

CrCl (mL/min)	Dosage
<15	Contraindicated.
15-29	Max: 25 mg once daily.

Moderate (Child-Pugh Class B): Max: 25 mg once daily. Severe (Child-Pugh Class C): Contraindicated.

XR tab: May be taken with or without food. Swallow whole, do not chew/crush/divide.

Severe uncontrolled HTN (systolic BP ≥180 mmHg or diastolic BP ≥110 mmHg). Severe hepatic impairment, ESRD, or haemodialysis patients. Lactation. Patients taking concomitant strong CYP3A inhibitors who have moderate to severe hepatic or severe renal impairment.

Patient w/ clinically significant bladder outlet obstruction, history of QT-interval prolongation, stage 2 HTN. Hepatic and renal impairment. Pregnancy.

Significant: HTN.
Nervous: Headache, dizziness.
CV: Tachycardia, palpitations, AF.
GI: Constipation, diarrhea, nausea, dry mouth, abdominal pain or distension, dyspepsia, gastritis.
Resp: Nasopharyngitis, upper resp tract infection, sinusitis, rhinitis.
Genitourinary: UTI, bladder pain, nephrolithiasis, vag infection, vulvovaginal pruritus.
Musculoskeletal: Arthralgia.
Ophthalmologic: Glaucoma.
Dermatologic: Pruritus, rash, urticaria, purpura, leukocytoclastic vasculitis.
Others: Fatigue.
Potentially Fatal: Angioedema of the face, lips, tongue, and/or larynx.

PO: C

Monitor BP at baseline and regularly during therapy.

Symptoms: Palpitations, increased pulse rate and systolic BP. Management: Symptomatic and supportive treatment.

Increased exposure w/ strong CYP3A inhibitors (e.g. ketoconazole). May increase exposure to CYP2D6 substrates (e.g. desipramine, metoprolol), digoxin, and warfarin. Increased risk of urinary retention w/ antimuscarinic agents (e.g. solifenacin, darifenacin) due to additive pharmacologic effect.

Description: Mirabegron relaxes detrusor smooth muscle in the bladder during the storage phase of micturition by selectively activating β₃-adrenergic receptors, thereby increasing bladder capacity.
Onset: W/in 8 wk.
Pharmacokinetics:
Absorption: Bioavailability: 29-35%. Time to peak plasma concentration: Approx 3.5 hr.
Distribution: Widely distributed in the body, including erythrocytes. Plasma protein binding: Approx 71%, mainly to albumin and α₁-acid glycoprotein.
Metabolism: Extensively metabolised via multiple pathways including dealkylation, oxidation, glucuronidation, and amide hydrolysis by multiple enzymes (e.g. butylcholinesterase, uridine diphospho-glucuronosyltransferase [UGT], CYP3A4, CYP2D6, and possibly by alcohol dehydrogenase) to form 2 major inactive metabolites.
Excretion: Via urine (55% as radiolabeled drug and approx 25% as unchanged drug) and faeces (34% as radiolabeled drug). Terminal elimination half-life: Approx 50 hr.

Source: National Center for Biotechnology Information. PubChem Database. Mirabegron, CID=9865528, https://pubchem.ncbi.nlm.nih.gov/compound/Mirabegron (accessed on Jan. 22, 2020)

Store at 25°C.
Any unused portions should be disposed of in accordance w/ local requirements.

Drugs for Bladder & Prostate Disorders

G04BD12 - mirabegron ; Belongs to the class of urinary antispasmodics.

Anon. Mirabegron. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 02/05/2017 .

Buckingham R (ed). Mirabegron. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 02/05/2017.

Joint Formulary Committee. Mirabegron. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 02/05/2017 .

McEvoy GK, Snow EK, Miller J et al (eds). Mirabegron. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 02/05/2017 .

Myrbetriq Tablet, Film Coated, Extended Release (Astellas Pharma US, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 02/05/2017 .