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)

Ciprofloxacin is highly effective but should be reserved as an alternative agent rather than first-line therapy for acute uncomplicated cystitis. 1

• Dosing: 250 mg orally twice daily for 3 days 1
• Fluoroquinolones have high efficacy but carry propensity for collateral damage (disruption of normal flora and promotion of resistance) 1
• Should only be used when other recommended agents (nitrofurantoin, trimethoprim-sulfamethoxazole) cannot be used 1
• The 100 mg twice daily for 3 days regimen represents the minimum effective dose 2

Complicated Urinary Tract Infections

For complicated UTIs, ciprofloxacin 250 mg orally twice daily is the standard regimen, with 500 mg once daily showing inferior efficacy. 3

• Dosing: 250 mg orally twice daily for 7-14 days 3
• The 500 mg once-daily regimen showed higher superinfection rates (mostly gram-positive cocci) and up to 18.4% lower eradication rates compared to divided dosing 3
• Twice-daily administration maintains superior bacteriological eradication (90.9% vs 84.0%) 3

Pyelonephritis (Uncomplicated)

Oral ciprofloxacin 500 mg twice daily for 7 days is appropriate for outpatient treatment only when fluoroquinolone resistance is <10% in the community. 1

• Oral regimen: 500-750 mg twice daily for 7 days 1
• Alternative: 1000 mg extended-release once daily for 7 days 1
• If fluoroquinolone resistance exceeds 10%, administer initial IV dose of ceftriaxone 1 g before starting oral ciprofloxacin 1
• IV regimen for hospitalized patients: 400 mg IV twice daily 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. 4, 5

• Dosing: 500-750 mg orally twice daily 4
• IV dosing: 400 mg IV every 12 hours 5
• Should only be considered when documented resistance to beta-lactams exists or when first-line agents cannot be used 5
• Avoid empiric use in settings where streptococci are likely pathogens 5

Acute Sinusitis

• Dosing: 500 mg orally twice daily for 10 days 4
• Effective against Haemophilus influenzae, penicillin-susceptible S. pneumoniae, and Moraxella catarrhalis 4

Skin and Soft Tissue Infections

Necrotizing Infections (Surgical Site/Perineum)

For surgical infections of the axilla or perineum, ciprofloxacin must be combined with metronidazole for anaerobic coverage. 1

• Oral regimen: 750 mg orally twice daily PLUS metronidazole 500 mg every 8 hours 1
• IV regimen: 400 mg IV every 12 hours PLUS metronidazole 500 mg IV every 8 hours 1
• Monotherapy is inadequate due to poor anaerobic coverage 1

Bite Wounds (Animal/Human)

• Dog/cat bites: 500-750 mg orally twice daily PLUS metronidazole 1
• Human bites: 500-750 mg orally twice daily PLUS metronidazole 1
• Ciprofloxacin misses MRSA and some anaerobes, requiring combination therapy 1

Bone and Joint Infections

• Dosing: 750 mg orally twice daily for extended duration (typically 4-6 weeks) 4
• Effective against Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa 4

Gastrointestinal Infections

Infectious Diarrhea

• Dosing: 500 mg orally twice daily for 3-5 days 4
• Effective against enterotoxigenic E. coli, Campylobacter jejuni, and Shigella species 4

Typhoid Fever

• Dosing: 500 mg orally twice daily for 10 days 4
• Does not eradicate chronic carrier state 4

Intra-Abdominal Infections

Ciprofloxacin MUST be combined with metronidazole for intra-abdominal infections. 4

• Dosing: 400 mg IV every 12 hours PLUS metronidazole 500 mg IV every 8 hours 4
• Monotherapy is inadequate due to poor anaerobic coverage, particularly against Bacteroides fragilis 4

Sexually Transmitted Infections

Gonorrhea

Ciprofloxacin is NO LONGER recommended for gonorrhea in most settings due to widespread quinolone resistance. 1

• Historical dosing (only if QRNG ruled out): 500 mg orally as single dose 1
• Contraindicated in men who have sex with men, patients with recent foreign travel, and infections acquired in California, Hawaii, or other high-resistance areas 1
• Ceftriaxone 125 mg IM is now the preferred agent 1

Bioterrorism/Special Infections

Cutaneous Anthrax (Post-Exposure Prophylaxis)

For anthrax exposure, ciprofloxacin 500 mg orally twice daily for 60 days is the recommended regimen. 1

• Dosing: 500 mg orally twice daily for 60 days 1
• IV alternative: 400 mg IV every 12 hours if oral route unavailable 1
• Extended 60-day duration necessary due to potential spore persistence 1

Pediatric Dosing

Complicated UTI/Pyelonephritis (Ages 1-17)

Ciprofloxacin is NOT first-line in pediatrics due to increased arthropathy risk but may be used for complicated UTIs when alternatives are inadequate. 1, 4

• Oral dosing: 10-20 mg/kg/dose twice daily (maximum 750 mg/dose) 1
• IV dosing: 10 mg/kg/dose every 8-12 hours (maximum 400 mg/dose) 1
• Pediatric infectious disease consultation suggested prior to use 1

Multidrug-Resistant Organisms

• Dosing for MDR infections: 400 mg IV every 8-12 hours 1
• Part of combination regimens for carbapenem-resistant Pseudomonas and difficult-to-treat resistant organisms 1
• Should be reserved for documented susceptibility when other options exhausted 1

Critical Dosing Considerations

Key contraindications and warnings:

• Avoid in pregnancy unless life-threatening infection (teratogenic effects on developing cartilage) 1
• Avoid in children <18 years except for specific indications due to arthropathy risk 1, 4
• Resistance developing rapidly in P. aeruginosa and S. aureus infections 5
• Poor streptococcal activity makes it inappropriate for empiric pneumonia treatment 4, 5
• Always combine with anaerobic coverage (metronidazole) for intra-abdominal or perineal infections 1, 4