Mirabegron Teva (Mirabegron)

Mirabegron is used to treat conditions within the overactive bladder disease family by improving bladder storage function.

• Overactive bladder: reduces urgency episodes and increases bladder capacity.
• Urinary urgency: lessens the sudden need to void.
• Urinary frequency: decreases the number of daytime voids.
• Urge urinary incontinence: lowers the occurrence of involuntary leakage.

• Mirabegron selectively activates β3‑adrenergic receptors located on detrusor smooth muscle cells in the urinary bladder. Stimulation of these receptors triggers a cascade that increases cyclic adenosine monophosphate (cAMP) levels, leading to relaxation of the detrusor muscle during the storage phase. This relaxation expands functional bladder capacity and diminishes involuntary contractions, thereby improving urinary storage symptoms. The effect is dose‑dependent and does not involve muscarinic pathways, distinguishing it from antimuscarinic agents.

Common and serious adverse reactions have been reported with mirabegron therapy.

Common Side Effects

• Hypertension: increase in blood pressure.
• Headache: mild to moderate intensity.
• Nasopharyngitis: upper respiratory tract infection symptoms.
• Constipation: reduced bowel movements.
• Dry mouth: decreased salivation.
• Urinary retention: difficulty emptying bladder.

Serious or Rare Side Effects

• Severe hypertension: markedly elevated blood pressure requiring medical intervention.
• Acute urinary retention: sudden inability to void, may need catheterization.
• Angioedema: swelling of face, lips, tongue or throat.
• Myocardial infarction: rare occurrence of heart attack.
• Bladder pain: persistent discomfort in the bladder region.

Before initiating mirabegron, clinicians should evaluate several safety considerations.

• Monitor blood pressure: check baseline and periodic measurements.
• Assess renal function: adjust use in severe impairment.
• Review cardiovascular history: caution in patients with uncontrolled hypertension.
• Evaluate for urinary retention risk: avoid in those with significant obstruction.
• Avoid use in uncontrolled hypertension: contraindicated when systolic >180 mmHg.
• Store at room temperature: keep in original packaging, protect from moisture.

Mirabegron may interact with other medicines through metabolic pathways and pharmacodynamic effects.

Major Interactions (Avoid)

• Strong CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may increase mirabegron exposure.
• Antihypertensive agents: mirabegron can reduce their efficacy, risking uncontrolled blood pressure.
• Anticholinergic drugs: combined use may exacerbate urinary retention.

Moderate Interactions (Monitor Closely)

• Moderate CYP2D6 inhibitors (e.g., duloxetine): may modestly raise mirabegron levels.
• Diuretics: additive effect on blood pressure and electrolyte balance.
• Other β3‑adrenergic agonists: potential for additive pharmacologic activity.