Megatas-S 25 Tablet ER is a combination medication containing Mirabegron 25 mg and Solifenacin 5 mg, formulated for extended release to provide sustained therapeutic effects in the management of overactive bladder (OAB) symptoms. Mirabegron, a selective β3-adrenoceptor agonist, facilitates relaxation of the detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle, thereby increasing bladder capacity. Solifenacin, a competitive muscarinic receptor antagonist, reduces bladder muscle contractions by inhibiting the action of acetylcholine on muscarinic receptors, effectively decreasing urgency, frequency, and urge incontinence episodes. The synergistic action of these two agents targets both the adrenergic and cholinergic pathways involved in bladder control, offering improved symptom relief compared to monotherapy. Megatas-S 25 Tablet ER is indicated for adult patients with OAB characterized by urinary urgency, frequency, and urge urinary incontinence. The extended-release formulation ensures consistent plasma concentrations, enhancing patient compliance and minimizing peak-related adverse effects. Common side effects may include dry mouth, constipation, headache, and hypertension. Use of Megatas-S 25 Tablet ER should be under medical supervision, with caution advised in patients with severe uncontrolled hypertension, urinary retention, or impaired hepatic or renal function.