Professional Information
Flavoxate (Systemic)
VA CLASSIFICATION
Primary: GU201
Commonly used brand name(s): Urispas.
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).
Category:
Antispasmodic (urinary tract)—
Indications
Accepted
Urologic disorders, symptoms of (treatment); and{01}
Irritative voiding, symptoms of (treatment){07}—Flavoxate is indicated for the symptomatic relief, but not the definitive treatment, of dysuria, urgency, nocturia, suprapubic pain, and frequency and incontinence associated with cystitis, prostatitis, urethritis, urethrocystitis, or urethrotrigonitis. {01} {03}
Pharmacology/Pharmacokinetics
Physicochemical characteristics:
Molecular weight—
427.93
Mechanism of action/Effect:
Exerts direct antispasmodic (relaxant) effect on smooth muscle, mainly of the urinary tract. {01}
Other actions/effects:
Also has weak antihistaminic, local anesthetic, and analgesic action. {09} With high doses, flavoxate has weak anticholinergic properties. {04} {05} {06}
Absorption:
Well absorbed from gastrointestinal tract. {02}
Elimination:
Renal (10 to 30% eliminated within 6 hours{02}; 57% eliminated in 24 hours {10})
Precautions to Consider
Pregnancy/Reproduction
Pregnancy—
Adequate and well-controlled studies in pregnant women have not been done.
Reproduction studies in rats and rabbits at doses up to 34 times the recommended human dose have not shown that flavoxate causes impaired fertility or adverse effects on the fetus. {01}{10}
FDA Pregnancy Category B. {01}{10}
Breast-feeding
It is not known whether flavoxate is distributed in breast milk. Caution should be used when flavoxate is prescribed to nursing women because many medications are distributed into human milk. {10}
Pediatrics
Appropriate studies on the relationship of age to the effects of flavoxate have not been performed in children younger than 12 years of age. Flavoxate is not recommended for this age group because safety and efficacy have not been established.{10}
Geriatrics
Confusion is more likely to occur in geriatric patients taking flavoxate. {07}
Dental
Prolonged use or use of large doses of flavoxate may decrease or inhibit salivary flow, {07} thus contributing to the development of caries, periodontal disease, oral candidiasis, and discomfort. {01}
Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).
Risk-benefit should be considered when the following medical problems exist
» Gastrointestinal tract obstructive disease as in achalasia and pyloroduodenal stenosis (decrease in motility and tone may occur, resulting in obstruction and gastric retention {01})
Glaucoma, angle-closure (mydriatic effect of flavoxate resulting in increased intraocular pressure may precipitate an acute attack of angle-closure glaucoma {01} {03})
» Hemorrhage, gastrointestinal{01} (may exacerbate condition)
» Paralytic ileus (may result in obstruction {01})
Sensitivity to flavoxate
» Uropathy, obstructive, such as bladder neck obstruction due to prostatic hypertrophy (urinary retention may be precipitated {01})
Side/Adverse Effects
Note: Although weak, flavoxate's anticholinergic action should be taken into consideration when it is given to patients where the environmental temperature is high, since there is risk of a rapid increase in body temperature because of suppression of sweat gland activity. {02}
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:
Those indicating need for medical attention
Incidence rare
Confusion —especially in the elderly {07}
hypersensitivity (skin rash or hives){01}
increased intraocular pressure (eye pain){01}
leukopenia (sore throat and fever){01}
Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent {01}
Drowsiness
dryness of mouth and throat
Incidence less frequent or rare {01}
Constipation —more frequent with doses of 800 mg or above
difficult urination
difficulty concentrating
difficulty in eye accommodation (blurred vision)
dizziness
fast heartbeat
headache
increased sweating
mydriatic effect (increased sensitivity of eyes to light)
nausea or vomiting
nervousness
stomach pain
Urticaria and other dermatosis ( hives){10}
Overdose
For specific information on the agents used in the management of flavoxate overdose, see:
• Thiopental in Anesthetics, Barbiturate (Systemic) monograph;
• Benzodiazepines (Systemic) monograph;
• Charcoal, Activated (Oral-Local) monograph;
• Chloral Hydrate (Systemic) monograph
For more information on the management of overdose or unintentional ingestion, contact a Poison Control Center (see Poison Control Center Listing ).
Clinical effects of overdose
The following effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parenthesis where appropriate)—not necessarily inclusive:
Anticholinergic effects (clumsiness or unsteadiness; severe dizziness; severe drowsiness; fever; flushing or redness of face; hallucinations; shortness of breath or troubled breathing; unusual excitement; nervousness; restlessness; or irritability)
Treatment of overdose
Recommended treatment for overdose with flavoxate includes: {04}
• To decrease absorption—Emesis or gastric lavage with 4% tannic acid solution or administration of an aqueous slurry of activated charcoal. {08}
• Specific treatment—Administration of small doses of short-acting barbiturate (100 mg thiopental sodium) or benzodiazepines, {08} or rectal infusion of 100 to 200 mL of a 2% solution of chloral hydrate, to control excitement. Artificial respiration with oxygen if needed for respiratory depression. {08} Adequate hydration. {08} Symptomatic treatment as necessary.
• Supportive care—Patients in whom intentional overdose is known or suspected should be referred for psychiatric consultation.
Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Flavoxate (Systemic).
In providing consultation, consider emphasizing the following selected information (» = major clinical significance):
Before using this medication
» Conditions affecting use, especially:
Sensitivity to flavoxate
Use in children—Flavoxate is not recommended for children younger than 12 years of age.
Use in the elderly—Confusion more likely
Dental—Dental—Possible development of dental problems because of decreased salivary flow
Other medical problems, especially gastrointestinal hemorrhage, paralytic ileus, or obstruction in gastrointestinal or urinary tract
Proper use of this medication
Taking medication on an empty stomach with water, or with food or milk to reduce gastric irritation
» Importance of not taking more medication than the amount prescribed
» Proper dosing
Missed dose: Taking as soon as possible; if almost time for next dose, not taking at all; not doubling doses
» Proper storage
Precautions while using this medication
Possible increased sensitivity of eyes to light
» Caution if drowsiness or blurred vision occurs
» Caution during exercise or hot weather; overheating may result in heat stroke
Possible dryness of mouth and throat; using sugarless gum or candy, ice, or saliva substitute for relief; checking with physician or dentist if dry mouth continues for more than 2 weeks
Side/adverse effects
Signs of potential side effects, especially hypersensitivity, confusion, increased intraocular pressure, and leukopenia
General Dosing Information
Flavoxate may be taken on an empty stomach with water; however, if gastric irritation occurs it may be taken with food or milk.
If urinary tract infection is present, appropriate antibacterial therapy should be administered.
Oral Dosage Forms
FLAVOXATE HYDROCHLORIDE TABLETS
Usual adult and adolescent dose
Urologic disorders or
Irritative voiding
Oral, 100 to 200 mg three or four times a day, the dosage being adjusted as needed and tolerated. {01}
Usual pediatric dose
Children up to 12 years of age–Use is not recommended because safety and efficacy have not been established.{10}Children 12 years of age and over–See Usual adult and adolescent dose.
Usual geriatric dose
See Usual adult and adolescent dose.
Strength(s) usually available
U.S.—
100 mg (Rx) [Urispas]
Canada—
200 mg (Rx) [Urispas]
Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer.
Auxiliary labeling:
• May cause drowsiness or blurred vision.
Revised: 02/23/2000
References
- Urispas product information. SKF, rev 4/88.
- McEvoy G, ed. AHFS drug Information. Bethesda: American Society of Hospital Pharmacists; 1991: 2194.
- Urispas product information. Pharmascience, 1991 CPS.
- Panel consensus, 1991 revision cycle.
- Ruffman R, Sartani A. Flavoxate, a drug with smooth muscle relaxing activity. Drugs Exp Clin Res 1987; 13[1]: 57-62.
- Ruffman R. A review of flavoxate hydrochloride in the treatment of urge incontinence. J Int Med Res 1988; 16: 317-30.
- AMA drug evaluations annual. Chicago: American Medical Association, 1992.
- Dreisbach R, Robertson W, ed. Handbook of poisoning. 12th ed, Norwalk CT: Appleton & Lange, 1987.
- Anderson K. Current concepts in the treatment of disorders of micturition. Drugs 1988; 35: 477-94.
- Product Information: Urispas flavoxate. Alza, Mountain View, CA, USA (PI revised 2/1995), reviewed 1/2000.
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