Megron 50

Indications

Mirabegron is used in adults to treat overactive bladder, with symptoms such as:

• a sudden, strong need to pass urine (urgency);
• passing urine more often than usual (frequency);
• leaking urine before reaching the toilet (urge incontinence).

How It Works

Mirabegron is a beta-3 adrenergic agonist. It acts on beta-3 receptors in the bladder muscle and helps it relax, so the bladder can hold more urine and the urge to pass urine happens less often.

Dosage and Administration

• Adults: usually 50 mg once a day. Some doctors start with 25 mg once a day and increase after a few weeks.
• Moderate kidney or liver problems: often 25 mg once a day, as prescribed.
• Children: not for overactive bladder in children unless prescribed by a specialist.

Swallow the prolonged-release tablet whole with water, with or without food. Do not crush, chew or split it. It may take a few weeks to see the full benefit.

Interactions

Mirabegron can raise the levels of some medicines, including Digoxin, Metoprolol, Flecainide, Propafenone and some tricyclic antidepressants, so the doctor may adjust their doses or check levels. Strong enzyme blockers such as Ketoconazole or Clarithromycin can raise mirabegron levels, especially in people with kidney or liver problems. Taking it with antimuscarinic bladder medicines (such as Solifenacin) can increase the chance of urine retention. Tell your doctor about all medicines you take.

Contraindications

• Allergy to Mirabegron or any ingredient of the tablet
• Severe, uncontrolled high blood pressure
• End-stage kidney disease or severe liver disease (not recommended)

Side Effects

Common: raised blood pressure, fast heartbeat, urinary tract infection, headache, dizziness, nausea, constipation or diarrhoea, and joint pain.

Less often: palpitations, rash, itching and swelling of the lips or eyelids.

Get medical help at once for: swelling of the face, lips, tongue or throat; trouble breathing; being unable to pass urine; very high blood pressure with severe headache, chest pain or blurred vision; or a racing or irregular heartbeat.

Pregnancy and Lactation

There is not enough information on safety in pregnancy, so it is not recommended. Women who could become pregnant should use contraception. It is not recommended during breastfeeding.

Precautions and Warnings

• Your blood pressure should be checked before starting and from time to time during treatment.
• Take extra care if you have a blocked bladder outlet (for example from an enlarged prostate) or weak bladder emptying.
• Take extra care with heart rhythm problems (such as long QT), kidney or liver disease.

Overdose

Too much may cause a fast heartbeat, palpitations and raised blood pressure. Contact a doctor or go to hospital; treatment is supportive.

Therapeutic Class

Urinary antispasmodic (beta-3 adrenergic agonist).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.