Mirabegron Zentiva (Mirabegron)

Mirabegron is a beta‑3 adrenergic agonist used in the management of lower urinary tract disorders associated with detrusor overactivity.

• Overactive bladder: increases bladder capacity and reduces urgency episodes.
• Urinary urgency: lessens the sudden need to void.
• Urinary frequency: decreases the number of daily voids.
• Urge urinary incontinence: helps prevent involuntary leakage triggered by urgency.

• Mirabegron selectively stimulates β3‑adrenergic receptors located on detrusor smooth muscle. Activation of these receptors raises intracellular cyclic AMP, leading to relaxation of the detrusor muscle during the storage phase of the bladder cycle, thereby increasing functional bladder capacity and reducing involuntary contractions.

Adverse reactions may occur with mirabegron therapy.

Common Side Effects

• Hypertension: elevated blood pressure readings.
• Nasopharyngitis: mild upper respiratory tract infection symptoms.
• Urinary tract infection: dysuria or increased frequency.
• Headache: mild to moderate intensity.
• Constipation: reduced bowel movements.
• Dry mouth: decreased salivation.

Serious or Rare Side Effects

• Urinary retention: inability to empty the bladder.
• Severe hypertension: markedly high blood pressure requiring medical intervention.
• Tachycardia: rapid heart rate.
• Angioedema: swelling of face, lips, or throat.
• Myocardial infarction: rare cardiac event.
• Anaphylactic reaction: severe allergic response.

Before initiating mirabegron, certain clinical considerations are recommended.

• Renal impairment: assess kidney function and adjust dose if needed.
• Hepatic impairment: monitor liver enzymes and consider dose modification.
• Cardiovascular disease: regularly check blood pressure and heart rate.
• Concomitant CYP2D6 inhibitors: anticipate increased mirabegron exposure.
• Pregnancy and lactation: safety not established; use only when benefit outweighs risk.
• Store below 25°C: keep in the original pack, protect from moisture.

Mirabegron may interact with several drug classes; clinicians should review patient medication lists.

Major Interactions (Avoid)

• Strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine): may raise mirabegron levels.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase exposure.
• Norepinephrine reuptake inhibitors: additive increase in blood pressure.
• Anticholinergic agents: may diminish therapeutic effect on bladder symptoms.

Moderate Interactions (Monitor Closely)

• Diuretics: monitor electrolytes and blood pressure.
• Antihypertensives: potential additive hypotensive effect.
• Warfarin: observe INR for possible changes.
• Digoxin: check serum levels for potential alteration.