Myrbetriq ( Mirabegron ) is a beta- 3 adrenergic agonist indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency.
Important safety information
Mirabegron can increase blood pressure. Periodic blood pressure determinations are recommended, especially in hypertensive patients. Myrbetriq is not recommended for use in severe uncontrolled hypertensive patients ( defined as systolic blood pressure greater than or equal to 180mm Hg and/or diastolic blood pressure greater than or equal to 110 mm Hg ).
Urinary retention in patients with bladder outlet obstruction and in patients taking antimuscarinic medications for the treatment of overactive bladder has been reported in postmarketing experience in patients taking Mirabegron. A controlled clinical safety study in patients with bladder outlet obstruction did not demonstrate increased urinary retention in Mirabegron patients; however, Mirabegron should be administered with caution to patients with clinically significant bladder outlet obstruction.
Myrbetriq should also be administered with caution to patients taking antimuscarinic medications for the treatment of overactive bladder.
Mirabegron is a moderate CYP2D6 inhibitor, the systemic exposure to CYP2D6 substrates such as Metoprolol and Desipramine is increased when co-administered with Mirabegron. Therefore, appropriate monitoring and dose adjustment may be necessary, especially with narrow therapeutic index drugs metabolized by CYP2D6, such as Thioridazine, Flecainide, and Propafenone.
When initiating a combination of Mirabegron and Digoxin, prescribe the lowest dose of Digoxin; monitor serum Digoxin concentration to titrate Digoxin dose to the desired clinical effect.
Most commonly reported adverse reactions ( greater than 2% and greater than placebo ) were hypertension, nasopharyngitis, urinary tract infection and headache. ( Xagena )
Source: Astellas, 2012