Mirabegron Aristo Aristo (Mirabegron)

Mirabegron is indicated for conditions affecting bladder storage function within the overactive bladder therapeutic area.

• Overactive bladder: improves bladder capacity and reduces episodes of urgency and frequency.
• Urinary urgency: lessens the sudden, compelling need to void.
• Urinary frequency: decreases the number of daytime voids.

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

Mirabegron may cause a range of adverse reactions, most of which are mild to moderate in severity.

Common Side Effects

• Hypertension: increase in blood pressure, often mild.
• Nasopharyngitis: inflammation of the nasal passages and throat.
• Headache: mild to moderate intensity.
• Urinary tract infection: symptoms of dysuria or frequency.
• Constipation: reduced bowel movements.
• Dry mouth: decreased salivation.

Serious or Rare Side Effects

• Severe hypertension: marked elevation of blood pressure requiring medical attention.
• Tachycardia: rapid heart rate that may be symptomatic.
• Urinary retention: difficulty initiating or maintaining urine flow.
• Angioedema: swelling of face, lips, or airway.
• Severe hypersensitivity reactions: rash, pruritus, or anaphylaxis.

When prescribing Mirabegron, clinicians should consider several safety aspects.

• Blood pressure monitoring: check baseline and periodically during therapy.
• Uncontrolled hypertension: avoid use or use with caution.
• Renal or hepatic impairment: dose adjustment may be required.
• Pregnancy and lactation: safety not established; use only if benefit outweighs risk.
• Concomitant antihypertensives: monitor for reduced efficacy.
• Store at ambient temperature: keep below 25°C, retain in original packaging, protect from moisture and direct sunlight.

Mirabegron can affect the pharmacokinetics of several co‑administered medicines.

Major Interactions (Avoid)

• Strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine): may increase Mirabegron exposure.
• Potent CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): can raise plasma levels.
• Other β3‑adrenergic agonists: additive bladder‑relaxant effect.

Moderate Interactions (Monitor Closely)

• CYP2D6 substrate drugs (e.g., metoprolol): possible increased plasma concentrations.
• Antihypertensive agents (e.g., ACE inhibitors, ARBs): may experience reduced blood‑pressure control.
• Diuretics: combined effect may elevate blood pressure.
• NSAIDs: increased risk of hypertension.