Gemtesa (Vibegron) for Overactive Bladder
Recommended Dosage
The recommended dosage of Gemtesa is 75 mg orally once daily, taken with or without food, and tablets should be swallowed whole with water (though they may be crushed and mixed with applesauce if needed). 1
Treatment Algorithm Position
Beta-3 agonists like vibegron are typically preferred before antimuscarinic medications due to their favorable side effect profile, particularly regarding cognitive effects 2
Behavioral therapies (bladder training, delayed voiding, pelvic floor muscle training, fluid management, weight loss) should be initiated as first-line therapy before pharmacologic treatment 2
When behavioral therapies fail to provide adequate symptom control, vibegron represents an appropriate second-line pharmacologic option 3, 2
If inadequate symptom control occurs with one medication, switching between beta-3 agonists and antimuscarinics or dose modification may be attempted 3
Clinical Efficacy
Vibegron demonstrates significant improvements in all three cardinal symptoms of overactive bladder: daily micturitions, urge urinary incontinence episodes, and urgency episodes 4, 5
Efficacy is evident as early as week 2 of treatment and is sustained through 52 weeks of continuous therapy 5, 6
Among patients with wet overactive bladder, 61% experienced ≥75% reduction in urge urinary incontinence episodes after 52 weeks, and 40.8% achieved complete dryness (100% reduction) 5
Special Population Considerations
Vibegron is particularly advantageous for elderly patients (≥65 years and ≥75 years), as it does not carry the same risk for cognitive impairment or dementia associated with antimuscarinic medications 2, 6
In patients aged ≥65 years, vibegron showed significant improvements versus placebo in micturitions (P<0.0001), urge urinary incontinence episodes (P<0.001), and urgency episodes (P<0.01) 6
Cardiovascular adverse events remain low (<2%) in elderly populations, with hypertension rates of only 1.2-1.3% in patients ≥65 years receiving vibegron 6
Safety Profile and Warnings
Monitor patients for urinary retention, particularly those with bladder outlet obstruction or those taking concomitant antimuscarinic medications; discontinue if urinary retention develops 1
Angioedema of the face and/or larynx can occur hours after the first dose or after multiple doses; immediately discontinue if tongue, hypopharynx, or laryngeal involvement occurs 1
Gemtesa is contraindicated in patients with known hypersensitivity to vibegron or any components 1
The most common adverse events (>5%) include hypertension (8.8%), urinary tract infection (6.6%), headache (5.5%), and nasopharyngitis (4.8%), with notably low rates of dry mouth (1.8%) compared to antimuscarinics 5
Combination Therapy
Combination therapy with behavioral therapy and vibegron may be considered for patients with inadequate response to monotherapy 2
Vibegron has been studied concomitantly with tolterodine and was well tolerated, though routine combination with antimuscarinics should be approached cautiously given limited evidence 4
Mechanism and Drug Interactions
Vibegron is a highly selective second-generation beta-3 adrenergic receptor agonist that does not interact with cytochrome P450 enzymes, making it advantageous for patients with polypharmacy 7
This lack of CYP interactions distinguishes vibegron from first-generation beta-3 agonists like mirabegron 7