Flavoxate

Clinical uses

Flavoxate is used to treat urinary bladder spasms. It is available under the trade name Urispas (Paladin),Genurin (by Recordati, Italy) in Italy and KSA,Uritac by El Saad company in Syria, under the name Bladderon by Nippon Shinyaku of Japan, or Bladuril in Chile, Utispas ( Apex Pharma) in Nepal.

Flavoxate is indicated for symptomatic relief of interstitial cystitis, dysuria, urgency, nocturia, suprapubic pain, frequency and incontinence as may occur in cystitis, prostatitis, urethritis, urethrocystitis/urethrotrigonitis.

Side effects

Flavoxate is generally well tolerated, but can potentially cause, vomiting, upset stomach, dry mouth or throat, blurred vision, eye pain, and increased sensitivity of your eyes to light.

Contraindications

Flavoxate is contraindicated in patients who have any of the following obstructive conditions: pyloric or duodenal obstruction, obstructive intestinal lesions or ileus, achalasia, gastrointestinal hemorrhage and obstructive uropathies of the lower urinary tract.

Synthesis

Nitration of hydroxypropiophenone (1) followed by conversion of the phenol to its methyl by means of MeI provides the intermediate 2; the nitro group is then reduced to the corresponding amine (3) by catalytic reduction. The newly formed amine is then replaced by a nitrile group by successive conversion to the diazonium salt by means of nitrous acid followed by treatment with cuprous cyanide (4). Rxn with aluminium chloride|AlCl₃]] cleaves the methyl ether to afford the ortho acylphenol (5). This is converted to the chromone/flavone (6) in a Kostanecki acylation rxn with BzCl and NaOBz. The nitrile is next hydrolyzed to the carboxylic acid (7) by means of SOCl₂ and that treated with β-Piperidylethanol. There is thus obtained flavoxate (8), a muscle relaxant whose name reflects its flavone nucleus.

See also