Mirabegron/Pharmazac 50 Mg (Mirabegron)

Mirabegron is used to treat symptoms of overactive bladder, a condition characterized by involuntary detrusor contractions.

• 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: improves control and reduces leakage episodes.

• Mirabegron selectively activates β3‑adrenergic receptors located on detrusor smooth muscle in the urinary bladder. Activation leads to relaxation of the detrusor muscle, which increases bladder storage capacity and reduces involuntary contractions, thereby alleviating symptoms of urgency, frequency, and urge incontinence.

Adverse reactions may occur with mirabegron therapy.

Common Side Effects

• Hypertension: elevation of blood pressure.
• Nasopharyngitis: inflammation of the nasal passages and throat.
• Urinary tract infection: bacterial infection of the urinary system.
• Headache: mild to moderate head pain.
• Constipation: reduced bowel movements.
• Dry mouth: decreased salivation.

Serious or Rare Side Effects

• Severe hypertension: markedly high blood pressure requiring medical attention.
• Tachycardia: rapid heart rate.
• Angioedema: swelling of face, lips, or airway.
• Urinary retention: difficulty emptying the bladder.
• Myocardial infarction: heart attack.
• Severe allergic reaction: anaphylaxis or systemic hypersensitivity.

Before initiating mirabegron, consider the following safety measures.

• Monitor blood pressure: check regularly as mirabegron may increase systolic and diastolic values.
• Assess renal function: use with caution in patients with severe renal impairment.
• Evaluate hepatic function: dose adjustment may be needed in moderate hepatic disease.
• Review concomitant β‑agonists: avoid additive cardiovascular effects.
• Pregnancy and lactation: safety not established; avoid unless benefit outweighs potential risk.
• Store at ambient temperature below 25 °C: keep in the original pack, protect from moisture.

Mirabegron may interact with other medicines; awareness of the interaction level is essential.

Major Interactions (Avoid)

• Strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine): increase mirabegron exposure.
• Norepinephrine reuptake inhibitors (e.g., duloxetine): may raise blood pressure.
• Monoamine oxidase inhibitors: risk of hypertensive crisis.
• Anticholinergic agents: may reduce mirabegron's efficacy.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin): may lower mirabegron plasma levels.
• Diuretics: additive effect on blood pressure control.
• NSAIDs: may increase risk of hypertension when combined.