Overactive bladder

Overactive bladder is simply as the name implies, the patient is experiencing frequent feelings of need for urinations, and the sensation doesn’t go unless fulfilled, and sometimes if the patient lost control then the experience will be transformed into incontinence.

We are covering today two molecules: Mirabegron and Vibegron.

Both are beta3 agonists, and both are approved for overactive bladder.

Mechanism of action

Beta-3 adrenergic receptor agonist, activates beta-3 adrenergic receptors in the bladder resulting in relaxation of the detrusor smooth muscle during the urine storage phase, thus increasing bladder capacity.

symptoms of Overactive Bladder

Non-pharmacologic therapies

The patient can retrain the bladder muscles, by trying to control the urination gradually and getting better at it with time. Another method is by pelvic muscle exercises.


Start with: 25 mg once daily;
may increase to 50 mg once daily after 4 to 8 weeks.
75 mg once daily.
Not recommended in adults with severe uncontrolled hypertension
(SBP ≥180 and/or DBP ≥110 mm Hg)
Use isn’t recommended with sever renal and hepatic impairment
both medications needs adjustment for some renal and liver patients.