Continue Nitrofurantoin and Expect Symptom Resolution Within 2–3 Days
You should continue the full 5-day course of nitrofurantoin 100 mg twice daily, as dysuria typically persists for 2–3 days after starting appropriate antibiotic therapy for uncomplicated cystitis. 1
Expected Timeline for Symptom Resolution
Dysuria and other lower urinary tract symptoms commonly persist for the first 48–72 hours of nitrofurantoin therapy, even when the antibiotic is working effectively. 1
Clinical cure rates with nitrofurantoin range from 88–93% for uncomplicated UTIs, with bacterial cure rates of 81–92%, confirming that this is highly effective therapy when given the full course. 1, 2
Complete the full 5-day regimen (100 mg twice daily) as recommended by the Infectious Diseases Society of America and European Society for Microbiology and Infectious Diseases; stopping early reduces efficacy significantly. 1, 2
When to Reassess or Change Therapy
If symptoms do not resolve by the end of the 5-day treatment course or if they recur within 2 weeks, obtain a urine culture with susceptibility testing and consider retreatment with a 7-day regimen using an alternative agent. 1
If symptoms worsen or new symptoms develop—specifically fever >38°C, flank pain, costovertebral angle tenderness, nausea, or vomiting—stop nitrofurantoin immediately and switch to a fluoroquinolone (e.g., ciprofloxacin) or third-generation cephalosporin, because nitrofurantoin does not achieve adequate renal tissue concentrations for pyelonephritis. 1
Red Flags Requiring Immediate Change in Management
Fever, flank pain, or systemic symptoms indicate possible upper tract infection (pyelonephritis), for which nitrofurantoin is contraindicated; these patients require ciprofloxacin 500 mg twice daily for 5–7 days or parenteral ceftriaxone for severe cases. 1
Worsening dysuria with hematuria or suprapubic pain after 3 days of therapy may suggest treatment failure or resistant organism; obtain urine culture and consider switching to trimethoprim-sulfamethoxazole (if local resistance <20%) or fosfomycin 3 g single dose. 1, 3
Common Pitfalls to Avoid
Do not stop nitrofurantoin prematurely at day 2 or 3 simply because symptoms persist; this leads to treatment failure and promotes resistance. 1, 4
Do not obtain routine post-treatment urine cultures if symptoms resolve completely; cultures are indicated only if symptoms persist after completing therapy or recur within 2 weeks. 1
Do not switch to a fluoroquinolone empirically for persistent dysuria alone without upper tract signs; this contributes to unnecessary fluoroquinolone use and accelerates resistance. 1
Symptomatic Management During Treatment
Ensure adequate hydration during treatment to prevent crystal formation and help flush bacteria from the urinary tract. 1
Over-the-counter phenazopyridine (urinary analgesic) may be used for 1–2 days to relieve dysuria while waiting for antibiotic effect, but it does not treat the infection. 1
Nausea and headache are the most common side effects of nitrofurantoin (occurring in 5.6–34% of patients) and are typically mild and self-limited. 1, 2, 4