(April 17, 2023)

Flavoxate is a synthetic muscarinic antagonist (anticholinergic) with urinary tract spasmolytic activity that is used for symptomatic alleviation in genitourinary conditions such as lower urinary tract infection, prostatitis, and urethritis (7).

• It does not have antibiotic properties, and should never be used as a replacement for appropriate antimicrobials.

• It should not be prescribed to patients with an increased risk of intestinal obstruction, ileus, or urinary retention, or any other conditions that may be aggravated by anticholinergic agents.

• While there is solid evidence regarding alleviating urgency for overactive bladder (4), and has a better safety profile than other antispasmodics (3), there is limited reassuring evidence (1) to support its usage in genitourinary infections.

Adult dose for symptomatic relief of urinary urgency, suprapubic pain secondary to urinary tract infections (UTIs)(7)

100-200mg every 6 to 8 hours PO

Adult dose for symptomatic relief of urinary urgency, suprapubic pain secondary to UTIs (7)

100-200mg every 6 to 8 hours PO

• US-FDA labeled (7)

  • Symptomatic relief of dysuria, urgency, nocturia, suprapubic pain, frequency and incontinence as may occur in cystitis, prostatitis, urethritis, urethrocystitis/urethrotrigonitis. 

  • Flavoxate hydrochloride tablets are not indicated for definitive treatment, but are compatible with drugs used for the treatment of urinary tract infections.

• Off-label

  • Not described

• Following timings are based on very limited data according to a study conducted in healthy individuals (7):

  • Onset of action: 55 min.

  • TTPE*: 112 min
    *time to peak effect

  • Elimination half-life:  ≈3.5h (4)

According to studies in guinea pigs, flavoxate may have a local anesthetic action similar to lidocaine, contributing to analgesic effect (3). 

• Do not use in patients with known narrow-angle glaucoma as it may trigger acute-closed angle glaucoma (2, 3). 

• Contraindicated in patients with a higher risk of intestinal obstruction, ileus or urinary retention, or other conditions that may worsen with anticholinergic agents.

• Following the recommendations of the 2019 Beer Criteria, it is advised to avoid, adjust dosage, or use with caution in older adults due to its strong anticholinergic properties (6).

Pregnancy risk classification

• AU TGA pregnancy category: B

• US FDA pregnancy category: not classified

Lactation

• Caution. It is unknown whether this drug is excreted in human milk (7). 

• Based on the pharmacological profile of flavoxate, it may pose a low risk for nursing infants. Monitor for anticholinergic symptoms such as irritability, nausea or constipation in the infant (5).

1. Servedio C. The use of flavoxate in cystitis and renal colic. Curr Med Res Opin. 1974;2(8):449-454. doi:10.1185/03007997409115241.
   Pubmed

2. Mohammed ZS, Simi ZU, Tariq SM, Ali KR. Bilateral acute angle closure glaucoma in a 50 year old female after oral administration of flavoxate. Br J Clin Pharmacol. 2008 Nov;66(5):726-7. doi: 10.1111/j.1365-2125.2008.03254.x. Epub 2008 Jul 8. PMID: 18754848; PMCID: PMC2661991.
   Pubmed Central

3. Arcaniolo D, Conquy S, Tarcan T. Flavoxate: present and future. Eur Rev Med Pharmacol Sci. 2015;19(5):719-731.
   Eur Rev Med Pharmacol Sci (Open Access) 

4. Sweeney P, Mutambirwa S, Van An N, Sharma JB, Vanamail P. Flavoxate in the symptomatic treatment of overactive bladder: a meta-analysis. Eur Rev Med Pharmacol Sci. 2016;20(17):3703-3712.
   Eur Rev Med Pharmacol Sci (Open Access)

5. APILAM (Association for promotion of and cultural and scientific research into breastfeeding). e-lactancia. Flavoxate hydrochloride. Updated June 2017. Accessed April 11, 2023.
   E-lactancia (Open Access)

6. American Geriatrics Society Beers Criteria® Update Expert Panel. American Geriatrics Society 2019 Updated AGS Beers Criteria® for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2019;67(4):674-694. doi:10.1111/jgs.15767.
   Pubmed

7. NIH-NLM (National Institutes of Health - National Library of Medicine). DailyMed. Label: Flavoxate Hydrochloride tablet, film coated. Updated in February 2022. Accessed March 30, 2023.
   DailyMed (Open Access)