Flavoxate Hcl

Flavoxate hydrochloride acts directly on the smooth muscle of the lower urinary tract, easing the involuntary contractions that create a sudden, painful need to pass water. Much of each dose is converted into an active metabolite that is cleared through the kidneys. Studies summarised in the SmPC show that it lets the bladder hold a larger volume and lowers the pressure at which it tries to empty, without notable effects on the heart or breathing. It treats the symptoms rather than the underlying infection or inflammation, which may need separate treatment. Symptoms that persist, or that come with fever or blood in the urine, should be reported to the GP so the cause can be looked into.

The UK licence covers symptomatic relief of painful or difficult urination, urgency, frequency, getting up at night, pain above the pubic bone and incontinence linked to cystitis, prostatitis, urethritis and related inflammation of the urethra and bladder neck. It is also indicated for spasm of the bladder and urethra caused by catheters or cystoscopy, before such procedures, and for symptoms that follow surgery on the lower urinary tract.

Only the 200 mg strength is offered, in packs of 30, 60, 90, 120 and 180 tablets. The pack pictured is an imported one rather than a UK pack, so its tablets may look different from the UK version, which is a white film-coated tablet embossed F 200. In the UK the Urispas name is licensed to Recordati Pharmaceuticals as a POM medicine, and it is the only flavoxate brand listed on the electronic medicines compendium.

For adults, older people included, the SmPC recommends one 200 mg tablet three times a day for as long as needed, taken after meals to reduce the chance of nausea. This means 600 mg a day is the standard amount, and larger packs simply cover more days rather than allowing extra doses. Use in children under 12 is not recommended because safety and benefit have not been shown. Since the active metabolite is removed by the kidneys, people with reduced kidney function need extra care.

The tablets must not be used by anyone allergic to the ingredients or with blockage of the stomach or bowel, paralytic ileus, bleeding from the gut, achalasia, urinary retention, glaucoma or myasthenia gravis. They contain lactose, so people with rare inherited sugar intolerances should avoid them. No formal interaction studies have been carried out, so it is sensible to give the prescriber a full list of other medicines. Avoiding flavoxate in pregnancy is preferred as a precaution, and it should not be taken while breastfeeding because a risk to the baby cannot be ruled out.

Nausea is the most frequently reported effect. Vomiting, dry mouth, indigestion, sleepiness, blurred or impaired vision and skin rash are uncommon; hives, itching, fatigue and difficulty passing urine are rare. Confusion, palpitations, liver changes with jaundice, a rise in eye pressure and severe allergic reactions have been reported after marketing without a known frequency. Anyone who feels drowsy or has blurred vision should not drive or operate machinery. Eye pain with blurred vision, swelling of the face or throat, or yellowing skin needs prompt medical help.

The GP or urologist decides whether flavoxate fits the clinical picture and how long it should be continued.