Flavoxate Hydrochloride

Approved Indications:

• Relief of urinary bladder spasm and associated symptoms such as dysuria, urgency, frequency, and incontinence.
• Treatment of symptoms related to urinary tract infections (as adjunct therapy), including bladder irritation.
• Management of overactive bladder (OAB) symptoms.
• Relief of pain, burning, and discomfort caused by urinary tract spasms or infections.

Off-label / Clinically Accepted Uses:

• Symptomatic management of neurogenic bladder disorders.
• Adjunctive therapy in urological procedures causing bladder irritation.

• Adults:
  Oral dose is typically 200 to 400 mg per day, divided into 2 to 3 doses. For example, 100–200 mg taken two or three times daily.
• Elderly:
  Use the lowest effective dose due to potential increased sensitivity and risk of side effects.
• Pediatrics:
  Safety and efficacy have not been established; generally not recommended.
• Special Populations:
• Renal impairment: Use with caution; no specific dose adjustments established.
• Hepatic impairment: Caution advised; insufficient data for dose adjustment.
• Administration:
  Tablets should be taken orally with a full glass of water. Can be taken with or without food.
• Duration:
  Use is symptomatic; discontinue when symptoms resolve.

Flavoxate hydrochloride acts primarily as a direct smooth muscle relaxant of the urinary bladder, exerting anticholinergic effects by blocking muscarinic receptors. This reduces detrusor muscle spasms and alleviates bladder irritability. By relaxing bladder smooth muscle, flavoxate decreases urgency, frequency, dysuria, and pain associated with bladder spasms and urinary tract irritation.

• Absorption:
  Flavoxate is well absorbed from the gastrointestinal tract after oral administration.
• Distribution:
  Distributed widely throughout body tissues; plasma protein binding data are limited.
• Metabolism:
  Undergoes hepatic metabolism, though specific metabolic pathways are not fully characterized.
• Elimination:
  Excreted primarily via urine; half-life ranges from 3 to 4 hours, supporting multiple daily dosing.

• Pregnancy:
  There are no well-controlled studies in pregnant women. Use only if clearly needed, as safety has not been established.
• Lactation:
  It is unknown whether flavoxate is excreted in human milk. Use caution when administered to nursing mothers.

• Primary class: Urinary antispasmodic
• Subclass: Direct-acting smooth muscle relaxant with anticholinergic properties

• Known hypersensitivity to flavoxate hydrochloride or formulation excipients
• Urinary retention or obstructive uropathy where bladder emptying is impaired
• Severe hepatic or renal impairment
• Glaucoma, particularly narrow-angle glaucoma
• Myasthenia gravis (due to anticholinergic effects)

• Use caution in patients with glaucoma, as flavoxate may increase intraocular pressure.
• Monitor for signs of urinary retention, especially in men with prostatic hypertrophy.
• Use cautiously in elderly patients due to increased risk of anticholinergic side effects (e.g., confusion, dry mouth, constipation).
• Avoid use in patients with impaired hepatic or renal function without medical supervision.
• Discontinue immediately if signs of allergic reaction or severe adverse effects occur.

Common Adverse Effects:

• Gastrointestinal: Nausea, vomiting, dry mouth
• Central Nervous System: Dizziness, headache, somnolence
• Urinary: Urinary retention or difficulty urinating
• Others: Blurred vision, flushing

Serious/Rare Side Effects:

• Allergic reactions such as rash, urticaria, or angioedema
• Confusion or hallucinations, particularly in elderly patients
• Severe urinary retention requiring intervention

• Other anticholinergic drugs: May potentiate anticholinergic effects, increasing risk of dry mouth, urinary retention, and CNS effects.
• Cholinergic agents: May reduce efficacy of flavoxate due to opposing actions.
• Alcohol and CNS depressants: Concomitant use may enhance sedative effects.
• Drugs affecting hepatic metabolism: Caution if combined with CYP450 inducers or inhibitors, though specific interactions are not well documented.

• No major recent changes in approved indications or dosing recommendations.
• Continued recognition of flavoxate’s role as an adjunctive therapy in bladder spasm and overactive bladder symptom management.
• Emphasis on cautious use in elderly due to anticholinergic burden.
• No new black box warnings added; monitoring for side effects remains important.

• Store at room temperature between 20°C and 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep in original container until use.
• Do not freeze.
• Keep out of reach of children.