From the Guidelines
For uncomplicated acute cystitis, the recommended first-line antibiotic treatments are nitrofurantoin (100 mg twice daily for 5 days), trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days), and fosfomycin (3 g single dose), as stated in the 2021 guidelines by the American College of Physicians 1.
Key Considerations
- Nitrofurantoin is preferred due to minimal resistance and limited collateral damage to gut flora.
- Trimethoprim-sulfamethoxazole remains effective in areas with resistance rates below 20% 1.
- Fosfomycin offers convenience with its single-dose regimen but may be slightly less effective.
Second-Line Options
- Fluoroquinolones like ciprofloxacin (250 mg twice daily for 3 days) or levofloxacin (250 mg daily for 3 days) should be reserved for cases where first-line agents cannot be used due to increasing resistance concerns and risk of adverse effects.
- Beta-lactams such as amoxicillin-clavulanate (500/125 mg twice daily for 5-7 days) are less preferred due to lower efficacy and more side effects.
Treatment Selection
- Consider local resistance patterns, patient allergies, pregnancy status, and renal function when selecting a treatment.
- Symptoms typically improve within 48 hours of starting treatment, and completing the full course is important to prevent recurrence and resistance development 1.
From the FDA Drug Label
To reduce the development of drug-resistant bacteria and maintain the effectiveness of sulfamethoxazole and trimethoprim tablets and other antibacterial drugs, sulfamethoxazole and trimethoprim tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to empiric selection of therapy Urinary Tract Infections For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris It is recommended that initial episodes of uncomplicated urinary tract infections be treated with a single effective antibacterial agent rather than the combination
The recommended antibiotic for treating uncomplicated acute cystitis is trimethoprim-sulfamethoxazole (PO), due to its effectiveness against susceptible strains of organisms such as Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis, and Proteus vulgaris 2.
- The treatment should be with a single effective antibacterial agent.
- Local epidemiology and susceptibility patterns should be considered in selecting therapy when culture and susceptibility information are not available.
From the Research
Recommended Antibiotics for Uncomplicated Acute Cystitis
The following antibiotics are recommended for treating uncomplicated acute cystitis:
- Nitrofurantoin 3, 4, 5, 6, 7
- Trimethoprim-sulfamethoxazole (TMP-SMX) 3, 4, 6
- Fosfomycin 3, 4, 6
- Pivmecillinam 4
First-Line Empiric Antibiotic Therapy
The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is:
- A 5-day course of nitrofurantoin 4
- A 3-g single dose of fosfomycin tromethamine 4
- A 5-day course of pivmecillinam 4
Second-Line Options
Second-line options include:
- Oral cephalosporins such as cephalexin or cefixime 4
- Fluoroquinolones 3, 4
- β-lactams, such as amoxicillin-clavulanate 4, 6
Considerations for Renal Insufficiency
Nitrofurantoin can be safe and effective in treating acute uncomplicated cystitis in hospitalized adults with renal insufficiency, but its use should be carefully considered in patients with severe renal impairment (CrCl < 30 ml/min) 7