FLAVALTA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for FLAVALTA (FLAVALTA).
Flavoxate is a smooth muscle relaxant with anticholinergic and local anesthetic properties. It inhibits phosphodiesterase, leading to increased cAMP levels, which reduces smooth muscle tone in the urinary tract.
| Metabolism | Primarily hepatic via glucuronidation and oxidation; major metabolite is 3-methylflavone-8-carboxylic acid. |
| Excretion | Primarily hepatic metabolism followed by biliary excretion (60-70% as metabolites), renal excretion (20-30% unchanged drug and metabolites), and fecal elimination (5-10%). |
| Half-life | Terminal elimination half-life is 6.5 hours (range 5.0-8.0 hours), allowing twice-daily dosing in most patients. |
| Protein binding | 99% bound primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 10-15 L/kg, indicating extensive extravascular distribution, including deep tissue compartments. |
| Bioavailability | Oral: 75-85% due to first-pass metabolism; Intravenous: 100%. |
| Onset of Action | Oral: 30-60 minutes; Intravenous: 5-10 minutes. |
| Duration of Action | 12-24 hours following oral administration; 8-12 hours after intravenous administration. |
FLAVALTA is not a recognized drug. No data available.
| Dosage form | SOLUTION |
| Renal impairment | No data available. |
| Liver impairment | No data available. |
| Pediatric use | No data available. |
| Geriatric use | No data available. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for FLAVALTA (FLAVALTA).
| Breastfeeding | Unknown if excreted in human milk. M/P ratio not available. Risk of severe adverse reactions in nursing infants; discontinue breastfeeding or discontinue drug. |
| Teratogenic Risk | Potential for cardiac, renal, and neural tube defects in first trimester based on animal data. Increased risk of preterm labor and IUGR in second and third trimesters. Contraindicated in pregnancy (Pregnancy Category X). |
| Fetal Monitoring |
■ FDA Black Box Warning
None.
| Serious Effects |
Pyloric or duodenal obstruction, obstructive intestinal lesions, ileus, achalasia, gastrointestinal hemorrhage, obstructive uropathy of the lower urinary tract.
| Precautions | May cause drowsiness, blurred vision, and decreased sweating. Use with caution in patients with glaucoma, urinary retention, gastrointestinal obstructive disorders, or myasthenia gravis. |
| Food/Dietary | No specific food interactions. Avoid excessive caffeine or acidic foods that may worsen urinary symptoms. Grapefruit has no known interaction with flavoxate. |
| Clinical Pearls |
Loading safety data…
| Serial fetal ultrasound for growth and anatomy. Nonstress test or biophysical profile weekly from 28 weeks. Maternal blood pressure, renal function, and liver enzymes monthly. |
| Fertility Effects | Reversible impairment of spermatogenesis in males and ovarian suppression in females. Reduced fertility indices in animal studies. |
| Flavalta (flavoxate) is a smooth muscle relaxant used for urinary urgency; no controlled trials support efficacy over placebo. Avoid in obstructive GI or urinary conditions. Anticholinergic effects may exacerbate narrow-angle glaucoma or urinary retention. Onset of action: 30-60 minutes; duration: 3-6 hours. No known QT prolongation or significant drug interactions. |
| Patient Advice | Take exactly as prescribed; may cause drowsiness or blurred vision, so avoid driving until effects are known. · Avoid alcohol and other CNS depressants as they can increase drowsiness. · Dry mouth is common; use sugar-free lozenges or ice chips. · Report difficulty urinating or eye pain immediately. · Do not crush or chew extended-release tablets. |