Indications And Dose
Urinary frequency, urgency, and urge incontinence ▶BY MOUTH ▶Adult: 50 mg once daily
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Drug reference
Urinary frequency, urgency, and urge incontinence ▶BY MOUTH ▶Adult: 50 mg once daily
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DUE TO INTERACTIONS ▶Manufacturer advises reduce dose to 25 mg once daily in patients with mild hepatic impairment with concurrent use of potent inhibitors of CYP3A4; avoid in moderate impairment. ▶Manufacturer advises reduce dose to 25 mg once daily if eGFR 30–89 mL/minute/1.73 m2 with concurrent use of potent inhibitors of CYP3A4; avoid if eGFR less than 30 mL/minute/1.73 m2.
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Severe uncontrolled hypertension (systolic blood pressure 180 mmHg or diastolic blood pressure 110 mmHg)
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History of QT-interval prolongation. stage 2 hypertension
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NICE decisions ▶Mirabegron for treating symptoms of overactive bladder (June 2013) NICE TA290 Mirabegron (Betmiga ®) is recommended as an option only for patients in whom antimuscarinic drugs are ineffective, contra-indicated, or not tolerated; patients currently receiving mirabegron who do not meet these criteria should have the option to continue until they and their clinician consider it appropriate to stop. www.nice.org.uk/guidance/ta290
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→Appendix 1: mirabegron
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▶Common or very common Arrhythmias. constipation. diarrhoea. dizziness. headache. increased risk of infection . nausea ▶Uncommon Cystitis. dyspepsia. gastritis. joint swelling. palpitations. skin reactions. vulvovaginal pruritus ▶Rare or very rare Angioedema. eyelid oedema. hypersensitivity vasculitis. hypertensive crisis. lip swelling. urinary retention ▶Frequency not known Insomnia
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Contraception advised in women of child-bearing potential.
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Avoid—toxicity in animal studies.
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Avoid—present in milk in animal studies.
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Manufacturer advises caution in moderate impairment (risk of increased exposure); avoid in severe impairment (no information available). Dose adjustments Manufacturer advises dose reduction to 25 mg once daily in moderate impairment.
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Avoid if eGFR less than 15 mL/minute/1.73 m2—no information available. Dose adjustments Reduce dose to 25 mg once daily if eGFR 15–29 mL/minute/1.73 m2.
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Blood pressure should be monitored before starting treatment and regularly during treatment, especially in patients with pre-existing hypertension.
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There can be variation in the licensing of different medicines containing the same drug. Modified-release tablet CAUTIONARY AND ADVISORY LABELS 25 ▶Betmiga (Astellas Pharma Ltd) Mirabegron 25 mg Betmiga 25mg modified-release tablets | 30 tablet P £29.00 DT = £29.00 Mirabegron 50 mg Betmiga 50mg modified-release tablets | 30 tablet P £29.00 DT = £29.00 1.2 Urinary retention Urinary retention Description of condition Urinary retention is the inability to voluntarily urinate. It may be secondary to urethral blockage, drug treatment (such as use of antimuscarinic drugs, sympathomimetics, tricyclic antidepressants), conditions that reduce detrusor contractions or interfere with relaxation of the urethra, neurogenic causes, or it may occur postpartum or postoperatively. Acute urinary retention is a medical emergency characterised by the abrupt development of the inability to pass urine (over a period of hours). Chronic urinary retention is the gradual (over months or years) development of the inability to empty the bladder completely, characterised by a residual volume greater than one litre or associated with the presence of a distended or palpable bladder. Urinary retention due to benign prostatic hyperplasia The most common cause of urinary retention in men is benign prostatic hyperplasia. Men with an enlarged prostate can have lower urinary tract symptoms associated with obstruction, such as urinary retention (acute or chronic), frequency, urgency or nocturia. Treatment Treatment of urinary retention depends on the underlying condition. Catheterisation is used to relieve acute painful urinary retention or when no cause can be found. Surgical procedures or dilatation are often used to correct mechanical outflow obstructions. Acute urinary retention g Acute retention is painful and requires immediate treatment by catheterisation. Before the catheter is removed an alpha-adrenoceptor blocker (such as alfuzosin hydrochloride below, doxazosin p. 826, tamsulosin hydrochloride p. 828, prazosin p. 827, indoramin p. 827 or terazosin p. 829) should be given for at least two days to manage acute urinary retention. h Chronic urinary retention g In patients with chronic urinary retention, intermittent bladder catheterisation should be offered before an indwelling catheter. Catheters may be used as a long-term solution where persistent urinary retention is causing incontinence, infection, or renal dysfunction and a surgical solution is not feasible. h Their use is associated with an increased risk of adverse events including recurrent urinary infections, trauma to the urethra, pain, and stone formation. g In men who have symptoms that are bothersome, drug treatment should only be offered when other conservative management options have failed. Men with moderate-to-severe symptoms should be offered an alpha- adrenoceptor blocker (alfuzosin hydrochloride, doxazosin, tamsulosin hydrochloride or terazosin). Treatment should Genito-urinary system initially be reviewed after 4–6 weeks and then every 6–12 months. h The parasympathomimetic bethanechol chloride p. 830 increases detrusor muscle contraction. It is licensed for acute postoperative, postpartum and neurogenic urinary retention but its use has largely been superseded by catheterisation. Urinary retention due to benign prostatic hyperplasia In patients with benign prostatic hyperplasia, treatment is influenced by the severity of symptoms and their effect on the patient’s quality of life. g Watchful waiting is suitable for men with symptoms that are not troublesome and in those who have not yet developed complications of benign prostatic hyperplasia such as renal impairment, urinary retention or recurrent infection. The recommended treatment of benign prostatic hyperplasia is usually an alpha-adrenoceptor blocker. The alpha1-selective adrenoceptor blockers relax smooth muscle in benign prostatic hyperplasia producing an increase in urinary flow-rate and an improvement in obstructive symptoms. In patients with an enlarged prostate, a raised prostate specific antigen concentration, and who are considered to be at high risk of progression (such as the elderly), a 5a- reductase inhibitor (such as finasteride p. 831 or dutasteride p. 830) should be used. A combination of an alpha- adrenoceptor blocker and a 5a-reductase inhibitor can be offered if symptoms remain a problem. Surgery is recommended for men with more severe symptoms that do not respond to drug therapy, or who have complications such as acute urinary retention, haematuria, renal failure, bladder calculi or recurrent urinary-tract infection. h Related drugs Other drugs used for urinary retention: neostigmine p. 1188, pyridostigmine bromide p. 1188. Useful Resources Lower urinary tract symptoms in men. National Institute for Health and Care Excellence. Clinical guideline CG97. May 2010 (updated June 2015). www.nice.org.uk/guidance/cg97 Other drugs used for Urinary retention Tadalafil, p. 860 ALPHA-ADRENOCEPTOR BLOCKERS
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50 mg once daily
First-line fragment. Read the complete Indications and Dose section above.
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