What is the recommended dosage and duration of ciprofloxacin (Cipro) for an adult patient with Pseudomonas aeruginosa folliculitis?

Ciprofloxacin Dosing for Pseudomonas aeruginosa Folliculitis in Adults

For an adult with Pseudomonas aeruginosa folliculitis, use ciprofloxacin 750 mg orally every 12 hours for 10-14 days. 1

Recommended Dosing Regimen

• Oral therapy: 750 mg every 12 hours is the preferred dose for Pseudomonas infections, providing higher serum and bronchial concentrations than standard 500 mg dosing 1
• This high-dose regimen is specifically recommended by the European Respiratory Society for cipro-sensitive Pseudomonas aeruginosa infections 1
• The 750 mg twice-daily dose achieves superior tissue penetration compared to lower doses, which is critical for skin and soft tissue infections 1

Treatment Duration

• Standard duration: 10-14 days for most Pseudomonas infections, with the specific duration determined by infection site and severity 1
• For folliculitis specifically, 10 days is typically adequate for mild-to-moderate cases, while 14 days should be used for more extensive or severe infections 1

When Monotherapy is Appropriate

• Monotherapy with ciprofloxacin is appropriate for mild-to-moderate folliculitis in immunocompetent patients with confirmed ciprofloxacin susceptibility 1
• This assumes the patient is clinically stable, can tolerate oral intake, and has no risk factors for severe infection 1

When to Escalate Therapy

Add an antipseudomonal beta-lactam or aminoglycoside if: 1

• The patient has severe infection or signs of systemic toxicity
• There is sepsis or bacteremia
• The patient is immunocompromised
• No clinical improvement occurs by day 3-5 of therapy 1

Intravenous Alternative

• If the patient cannot take oral therapy or has severe infection requiring hospitalization, use 400 mg IV every 8 hours 1
• The every-8-hour frequency (rather than every 12 hours) is preferred for Pseudomonas infections to optimize pharmacodynamic exposure 1
• Switch from IV to oral by day 3 if clinically stable 1

Critical Monitoring Points

• Obtain culture and susceptibility testing before starting antibiotics to confirm ciprofloxacin susceptibility 1
• Assess clinical response within 72 hours of initiating therapy 1
• If no improvement by day 3-5, consider switching to IV combination therapy with an antipseudomonal β-lactam plus aminoglycoside or continuing ciprofloxacin 1

Common Pitfalls to Avoid

• Never use 500 mg twice daily for Pseudomonas infections - this standard dose is inadequate and increases risk of treatment failure and resistance development 1, 2
• Do not extend treatment beyond 14 days with oral monotherapy, as this promotes resistance without proven benefit 1
• Avoid underdosing, which leads to treatment failure and resistance emergence, particularly when initial MICs are >0.5 mg/L 3, 2