Flavoxate hydrochloride is a urinary antispasmodic agent used primarily for the symptomatic relief of dysuria, urgency, nocturia, suprapubic pain, frequency, and incontinence associated with various urological conditions. It acts as a direct smooth muscle relaxant with anticholinergic properties, specifically targeting the lower urinary tract. In the Indian context, it is a widely prescribed first-line therapy for overactive bladder (OAB) symptoms and bladder spasms.
Adult: 200 mg orally three to four times daily. The usual recommended dose is one 200 mg tablet 3-4 times a day.
Note: Tablet should be swallowed whole with a full glass of water, with or without food. If gastrointestinal upset occurs, administer with food. Do not crush or chew. Maintain adequate fluid intake unless contraindicated.
Flavoxate exerts its therapeutic effect through a dual mechanism: 1) Direct smooth muscle relaxation of the detrusor muscle in the urinary bladder, independent of muscarinic blockade. 2) Competitive antagonism of muscarinic acetylcholine receptors (primarily M1 and M3 subtypes) in the bladder, reducing involuntary contractions. This combined action increases bladder capacity, delays the initial desire to void, and reduces the frequency of uninhibited contractions.
Pregnancy: Category B: Animal reproduction studies have not shown a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women. Use only if clearly needed and potential benefit justifies potential risk to the fetus.
Driving: May cause dizziness, drowsiness, and blurred vision. Patients should be cautioned about operating machinery or driving until they are reasonably certain that flavoxate does not affect them adversely.
| Other Anticholinergics (e.g., Oxybutynin, Tolterodine, Atropine, TCAs) | Additive anticholinergic side effects (dry mouth, constipation, urinary retention, blurred vision, tachycardia). | Major |
| Potassium Chloride (wax-matrix tablets) | Increased risk of gastrointestinal lesions; flavoxate may delay GI transit. | Moderate |
| CNS Depressants (e.g., Alcohol, Benzodiazepines, Opioids) | Enhanced sedative effects, increased drowsiness and dizziness. | Moderate |
| Metoclopramide | Antagonizes the prokinetic effect of metoclopramide on GI motility. | Moderate |
| Digoxin | Theoretical risk of increased digoxin absorption due to reduced GI motility; monitor digoxin levels. | Minor |
Same composition (Flavoxate (200mg)), different brands: