What is the recommended dose of daptomycin (Daptomycin) for a 33-year-old male with normal renal function (CrCl - Creatinine Clearance), weighing 79 kg, with a bloodstream infection?

Daptomycin Dosing for Bloodstream Infection

For this 33-year-old male (79 kg) with normal renal function (CrCl 120 mL/min) and bloodstream infection, administer daptomycin 6 mg/kg IV once daily (474 mg daily), which equals approximately 475-500 mg IV once daily for at least 2 weeks if uncomplicated, or 4-6 weeks if complicated. 1

Standard Dosing for Bacteremia

• The IDSA guidelines recommend daptomycin 6 mg/kg/dose IV once daily as first-line therapy for bloodstream infections (Grade A-I evidence). 1
• For this patient: 79 kg × 6 mg/kg = 474 mg IV once daily 1
• No renal dose adjustment is needed since CrCl is >30 mL/min 1

Duration Based on Complexity

Uncomplicated bacteremia (if all criteria met): minimum 2 weeks 1

• Endocarditis excluded
• No implanted prostheses
• Follow-up blood cultures at 2-4 days negative
• Defervescence within 72 hours
• No metastatic infection sites 1

Complicated bacteremia (if any above criteria not met): 4-6 weeks depending on extent of infection 1

Higher Dose Considerations

• Some experts recommend 8-10 mg/kg/dose IV once daily for complicated bacteremia or endocarditis (Grade B-III). 1
• Higher doses (8-10 mg/kg) are supported by pharmacodynamic data showing improved AUC/MIC ratios, particularly for organisms with reduced susceptibility 1
• Clinical data from 250 patients showed high-dose daptomycin (≥8 mg/kg/day) achieved 83.6% clinical success with only 1.2% adverse events 2
• A study of 31 patients receiving mean 8 mg/kg/day showed 94% clinical success versus 73% with standard dosing 3

Monitoring Requirements

Weekly CPK monitoring is mandatory for all patients. 4

• More frequent CPK monitoring if: 4

  • Renal insufficiency present (not applicable here)
  • Concurrent statin therapy
  • Doses >6 mg/kg/day 4

• Discontinue daptomycin if: 4

  • CPK elevation with muscle symptoms
  • Signs of rhabdomyolysis
  • Eosinophilic pneumonia develops 4

Essential Diagnostic Workup

Obtain echocardiography (TEE preferred over TTE) for all patients with bacteremia to exclude endocarditis. 1

Repeat blood cultures 2-4 days after initial positive cultures to document clearance. 1

Identify and eliminate/debride source of infection. 1

Critical Pitfalls to Avoid

• Do not use daptomycin for pneumonia - it is inactivated by pulmonary surfactant 4
• Do not add gentamicin or rifampin to daptomycin for bacteremia - combination therapy is not recommended and may worsen outcomes 1
• Ensure adequate dosing by actual body weight, not ideal body weight 1