Bladder‑Relaxant Therapies That Do Not Cause Hypotension

Antimuscarinic (Anticholinergic) Agents

In patients with overactive bladder, antimuscarinic drugs (e.g., oxybutynin, tolterodine, solifenacin, darifenacin, fesoterodine, trospium) are not associated with hypotension. 1
Tolterodine shows a lower discontinuation rate due to adverse effects compared with placebo, indicating better tolerability. 1
Solifenacin demonstrates the lowest overall risk of discontinuation due to adverse effects among antimuscarinics. 1
Darifenacin, an M3‑selective agent, has no significant difference in discontinuation rates versus placebo, suggesting comparable safety. 1
The most frequent adverse effect of antimuscarinics is dry mouth; clinicians should counsel patients accordingly. 1
Constipation is another common side effect of this drug class. 1
Blurred vision may also occur with antimuscarinic therapy. 1
When prescribing antimuscarinics, monitor for dry mouth, constipation, cognitive changes (especially in older adults), and urinary retention. 1

Mirabegron is well‑tolerated and does not significantly alter voiding parameters or post‑void residual volume in patients with overactive bladder. 2
The drug is contraindicated in patients with severe uncontrolled hypertension; blood pressure should be checked before initiation. 2
Reported adverse events with mirabegron include hypertension (as opposed to hypotension), urinary tract infections, headache, and nasopharyngitis. 2

Early, non‑selective alpha‑blockers used for urinary symptoms were associated with hypotension and dizziness, making them unsuitable when avoidance of hypotension is a priority. 3
Later‑generation selective alpha‑1 blockers reduce but do not eliminate cardiovascular side effects, and a residual risk of hypotension remains. 3
Alpha‑blockers are indicated for bladder outlet obstruction (facilitating emptying) rather than for detrusor overactivity or storage symptoms; they act on the bladder neck and urethra, not the detrusor muscle. 3

First‑line therapy for detrusor overactivity/storage symptoms without hypotension risk: start with an antimuscarinic; prefer tolterodine or darifenacin if minimizing discontinuation is a priority, or solifenacin for the lowest overall discontinuation risk. 1
Alternative therapy: use mirabegron when antimuscarinics are contraindicated or poorly tolerated, after confirming acceptable blood pressure and avoiding use in severe uncontrolled hypertension. 2
Avoid alpha‑blockers for storage‑symptom management when hypotension avoidance is essential; reserve them for cases of bladder outlet obstruction, acknowledging the persistent cardiovascular risk. 3

The American Urological Association recommends oxybutynin as the first-line treatment for bladder spasms at a dose of 0.2 mg/kg orally given three times daily, particularly for patients with neurogenic bladder 4, 5
Oxybutynin is indicated for treatment of detrusor overactivity in patients with neurogenic bladder and is the standard first-line medication for bladder spasms, with a recommended dose of 0.2 mg/kg orally three times daily 4, 5
Solifenacin has shown superior efficacy compared to tolterodine for treating overactive bladder symptoms and may have a lower risk of dry mouth, according to the International Continence Society 6

Standard oxybutynin dosing is 0.2 mg/kg orally three times daily for neurogenic bladder, as recommended by the American Urological Association 4, 5

Oxybutynin is the first choice for treatment of bladder spasms, with a standard dose of 0.2 mg/kg three times daily, as recommended by the European Association of Urology 4, 5

Other common side effects of antimuscarinic medications include constipation and blurred vision, according to the American College of Physicians 7
Changing to a different antimuscarinic with a better side effect profile may be considered if side effects are intolerable, as suggested by the National Institute for Health and Care Excellence 7

Evaluate for side effects at each follow-up visit, as recommended by the American Urological Association 4
For patients with neurogenic bladder, urodynamic studies may be needed to assess treatment effectiveness, according to the International Continence Society 4, 5