What is the recommended dosage and treatment regimen for Ciprofloxacin (ciprofloxacin) for various bacterial infections?

Ciprofloxacin Dosing and Treatment Regimens for Bacterial Infections

Urinary Tract Infections

Acute Uncomplicated Cystitis (Women)

For acute uncomplicated cystitis in women, ciprofloxacin 250 mg orally twice daily for 3 days is the minimum effective regimen, though fluoroquinolones should be reserved for cases where first-line agents cannot be used. 1, 2

• Ciprofloxacin 100 mg twice daily for 3 days has been shown to be the absolute minimum effective dose with 93% eradication rates 3
• The 250 mg twice daily for 3 days regimen achieved 90% bacteriologic eradication and 100% clinical success 3
• Important caveat: Fluoroquinolones have propensity for collateral damage and should be reserved for important uses other than acute cystitis 1
• Use only when local fluoroquinolone resistance is known to be <10% 1

Complicated Urinary Tract Infections

For complicated UTIs, ciprofloxacin 250 mg orally twice daily for 7-20 days is superior to once-daily dosing and remains the standard regimen. 4

• The twice-daily 250 mg regimen achieved 90.9% bacteriologic eradication versus 84.0% with 500 mg once daily 4
• Once-daily dosing resulted in more superinfections, predominantly gram-positive cocci 4
• For severe cases requiring hospitalization, initiate with IV ciprofloxacin 400 mg every 12 hours, then switch to oral after minimum 3 days 5

Pyelonephritis

For acute uncomplicated pyelonephritis, oral ciprofloxacin 500 mg twice daily for 7 days is appropriate only when fluoroquinolone resistance is <10%; if resistance exceeds 10%, give an initial IV dose of ceftriaxone 1 g before starting ciprofloxacin. 1

• Alternative: Ciprofloxacin 1000 mg extended-release once daily for 7 days 1
• Alternative: Levofloxacin 750 mg once daily for 5 days 1
• For hospitalized patients: IV ciprofloxacin 400 mg twice daily initially 1
• Critical point: Always obtain urine culture before starting therapy 1

Respiratory Tract Infections

Lower Respiratory Tract Infections

Ciprofloxacin is NOT a first-choice agent for pneumonia, particularly for Streptococcus pneumoniae, due to poor streptococcal activity. 2, 6

• For acute exacerbations of chronic bronchitis: 500-750 mg orally twice daily 2
• IV dosing for hospitalized patients: 400 mg every 12 hours 5
• Major limitation: Poor activity against streptococci makes empiric use inappropriate in settings where these organisms are likely 6

Skin and Soft Tissue Infections

Uncomplicated Infections

For mild-to-moderate skin infections, ciprofloxacin 500-750 mg orally twice daily can be used 1, 2

Necrotizing Infections and Surgical Site Infections

For necrotizing fasciitis or surgical site infections involving the axilla or perineum, use ciprofloxacin 400 mg IV every 12 hours (or 750 mg orally every 12 hours) PLUS metronidazole 500 mg every 8 hours. 1

• This combination regimen provides coverage for mixed aerobic-anaerobic infections 1
• Ciprofloxacin alone misses anaerobes and MRSA 1

Animal Bites

For dog bites: Ciprofloxacin 500-750 mg orally twice daily (or 400 mg IV every 12 hours) provides good activity against Pasteurella multocida but misses MRSA and some anaerobes 1

For human bites: Same dosing, but ciprofloxacin misses Eikenella corrodens—consider alternative agents 1

Gastrointestinal Infections

Infectious Diarrhea

Ciprofloxacin 500 mg orally twice daily when antibacterial therapy is indicated for enterotoxigenic E. coli, Campylobacter jejuni, or Shigella species 2

Typhoid Fever

Ciprofloxacin is indicated for Salmonella typhi, though specific dosing not detailed in guidelines 2

Bone and Joint Infections

Ciprofloxacin is indicated for osteomyelitis caused by Enterobacter cloacae, Serratia marcescens, or Pseudomonas aeruginosa 2

Intra-Abdominal Infections

Use ciprofloxacin 400 mg IV every 12 hours (or 750 mg orally every 12 hours) in combination with metronidazole 500 mg every 8 hours for complicated intra-abdominal infections. 1, 2

Sexually Transmitted Infections

Gonorrhea

Ciprofloxacin 500 mg orally as a single dose should NOT be used for gonorrhea in men who have sex with men (MSM) or in patients with recent foreign travel due to quinolone-resistant N. gonorrhoeae (QRNG). 1

• Only use in heterosexuals without travel history and outside California/Hawaii 1
• Must be given with treatment for chlamydia if chlamydial infection not ruled out 1

Bioterrorism Agents

Cutaneous Anthrax

Ciprofloxacin 500 mg orally twice daily for 60 days for naturally acquired cutaneous anthrax 1

For bioterrorism exposure: 500 mg orally twice daily for 60 days 1

Inhalational Anthrax

For inhalational anthrax, ciprofloxacin 400 mg IV every 12 hours should be part of first-line combination therapy; continue for 60 days total (may switch to oral 500 mg twice daily when clinically appropriate). 1

• IV ciprofloxacin may be replaced with oral if patient can absorb medications (though IV preferred initially) 1
• Must be combined with additional agents for inhalational disease 1

Pediatric Dosing

Multidrug-Resistant Organisms

Pediatric infectious diseases consultation is recommended before using ciprofloxacin in children due to arthropathy risk. 1

• Children: 10-20 mg/kg/dose orally every 12 hours (maximum 750 mg/dose) 1
• IV dosing: 10 mg/kg/dose every 8-12 hours (maximum 400 mg/dose) 1

Complicated UTI/Pyelonephritis (Ages 1-17)

Ciprofloxacin is FDA-approved for complicated UTI and pyelonephritis in children, but is NOT first-choice due to increased joint-related adverse events 2

Critical Warnings and Limitations

Ciprofloxacin should NOT be used empirically in intensive care settings where Pseudomonas aeruginosa, Staphylococcus aureus, or streptococci are likely pathogens due to poor activity and rapidly developing resistance. 6

• Bacterial resistance is becoming more prevalent, especially with P. aeruginosa and S. aureus 6
• IV ciprofloxacin is nearly 10 times more expensive than oral with no proven superiority 6
• Reserve for documented susceptibility, documented hypersensitivity to first-line agents, or inability to use oral formulations 6