Gemtesa (Vibegron): A Beta-3 Adrenergic Receptor Agonist for Overactive Bladder
Gemtesa (vibegron) is a selective beta-3 adrenergic receptor agonist FDA-approved for treating overactive bladder (OAB) symptoms including urge urinary incontinence, urgency, and urinary frequency in adults. 1
Mechanism of Action
Vibegron works by selectively activating beta-3 adrenergic receptors in the bladder, which:
- Relaxes the detrusor smooth muscle during bladder filling
- Increases bladder capacity
- Reduces symptoms of urgency, frequency, and incontinence 1
Dosing and Administration
- Standard dose: 75 mg tablet once daily
- Can be taken with or without food
- Tablets can be swallowed whole with water or crushed and mixed with a tablespoon of applesauce and taken immediately with water 1
- No dosage adjustment needed for patients with mild to moderate hepatic impairment or renal impairment (eGFR ≥15 mL/min/1.73 m²) 1
Clinical Efficacy
Vibegron demonstrates significant improvements over placebo in:
- Reducing micturition frequency
- Decreasing urgency episodes
- Reducing urgency incontinence episodes
- Increasing voided volume per micturition 2
The American Urological Association and Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction recognize vibegron as an effective pharmacological option for OAB treatment 3.
Safety Profile
Vibegron has a favorable safety profile compared to antimuscarinic agents:
- Lower incidence of dry mouth and constipation
- No significant impact on blood pressure in clinical studies 4
- No clinically significant QT interval prolongation 1
Common side effects include:
- Headache
- Nasopharyngitis
- Urinary tract infection
- Diarrhea
- Nausea
- Upper respiratory tract infection 1
Special Considerations
Cardiovascular Safety
- No meaningful increase in blood pressure or heart rate observed in clinical trials, even in patients with pre-existing hypertension 4
- Regular blood pressure monitoring is still recommended, especially in patients with pre-existing hypertension 3
Elderly Patients
- No dosage adjustment required for elderly patients
- Particularly beneficial for older adults due to lower risk of cognitive side effects compared to antimuscarinic agents 3, 5
- No overall differences in safety or effectiveness observed between patients ≥65 years and younger adults 1
Drug Interactions
- Minimal drug interactions due to limited metabolism by CYP enzymes 5
- Beneficial for patients on multiple medications 5
Contraindications and Warnings
- Contraindicated in patients with hypersensitivity to vibegron or any components of the formulation 1
- Not recommended in patients with severe hepatic impairment (Child-Pugh C) 1
- Not recommended in patients with severe renal impairment (eGFR <15 mL/min/1.73 m²) 1
- Associated with urinary retention risk, particularly in patients with bladder outlet obstruction 1
- Risk of angioedema (discontinue immediately if symptoms occur) 1
Place in Therapy
Vibegron represents an important addition to OAB treatment options:
- Can be used as a second-line pharmacological treatment after behavioral therapies 3
- May be preferred over antimuscarinic agents in elderly patients or those with cognitive concerns 3
- Particularly effective for patients with "wet OAB" (with urinary incontinence) 5
- Can be used in combination therapy with solifenacin 5 mg for patients with inadequate response to monotherapy 3
Vibegron offers an effective treatment option with a favorable side effect profile and minimal drug interactions, making it particularly valuable for elderly patients and those on multiple medications.