Empirical antibiotic therapy for acute cystitis in nonpregnant adult females

See Approach to empirical antibiotic choice for UTI in adults and Rationale for empirical antibiotic therapy for acute cystitis in adults for a discussion of antibiotic choice.

For empirical therapy for acute cystitis in nonpregnant adult females, useCai, 2020Huttner, 2018Nelson, 2024Wang, 2020:

1nitrofurantoin 100 mg orally, 6-hourly for 5 days12. For dosage adjustment in adults with kidney impairment, see nitrofurantoin dosage adjustmentnitrofurantoin nitrofurantoin nitrofurantoin

OR

2fosfomycin 3 g orally, as a single dose3 fosfomycin fosfomycin fosfomycin

OR

3trimethoprim 300 mg orally, daily for 3 days4. For dosage adjustment in adults with kidney impairment, see trimethoprim dosage adjustment. trimethoprim trimethoprim trimethoprim

If nitrofurantoin, fosfomycin or trimethoprim cannot be used for empirical therapy for acute cystitis in nonpregnant adult females, useYetsko, 2023:

cefalexin 500 mg orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see cefalexin dosage adjustment. cefalexin cefalexin cefalexin

If urine culture and susceptibility testing were performed and the pathogen is resistant to empirical therapy, do not modify the antibiotic therapy if symptoms of cystitis are improving. If the pathogen is resistant to empirical therapy and symptoms of cystitis are not improving, use the narrowest spectrum antibiotic to which the pathogen is susceptible.

Do not perform post-treatment urine culture to confirm resolution of infection for asymptomatic nonpregnant females.

For patients with ongoing cystitis symptoms following appropriate antibiotic therapy, consider seeking expert urology advice.

1 An alternative regimen is 100 mg 12-hourly for 5 days. This is from a study using Macrobid®, a slow-release formulation unavailable in Australia.Return
2 Retrospective data suggest that nitrofurantoin is safe and effective for short-term treatment (5 to 7 days) of acute cystitis in patients with a glomerular filtration rate (GFR) of 30 mL/min or moreCunha, 2017Geerts, 2013Santos, 2016Singh, 2015.Return
3 At the time of writing, fosfomycin is not available on the Pharmaceutical Benefits Scheme (PBS). See the PBS website for current information.Return
4 If the patient has been treated with trimethoprim in the previous 3 months, or had a trimethoprim-resistant Escherichia coli isolate during this time, use an alternative antibiotic for empirical therapy.Return