What antibiotics have good tissue penetration?

Antibiotics with Good Tissue Penetration

Fluoroquinolones (particularly levofloxacin and ciprofloxacin) and linezolid demonstrate the best overall tissue penetration across multiple body compartments, making them preferred agents when tissue penetration is critical. 1, 2

Fluoroquinolones: Superior Tissue Penetration

Fluoroquinolones achieve excellent tissue concentrations and are the gold standard for infections requiring deep tissue penetration. 1

Levofloxacin

• Achieves 2-5 fold higher concentrations in lung tissue compared to plasma (2.4 to 11.3 mcg/g over 24 hours) 2
• Skin tissue biopsy to plasma AUC ratio is approximately 2, with blister fluid to plasma ratio of approximately 1 2
• Excellent prostate tissue penetration, making it highly effective for prostatitis 1, 3, 4
• Bioavailability is approximately 99% for both oral and IV formulations, allowing interchangeable routes 2
• Peak concentrations in tissues occur at approximately 3 hours after dosing 2

Ciprofloxacin

• Produces the highest concentrations in prostatic tissue among fluoroquinolones, followed by enoxacin and lomefloxacin 3
• High tissue concentrations in diabetic foot infections, even in patients with gastroparesis 1
• Achieves therapeutic levels in skin, soft tissue, and bone 5

Other Fluoroquinolones

• Moxifloxacin demonstrates good pancreatic tissue penetration with excellent anaerobic coverage 1
• Ofloxacin shows effective prostatic fluid and tissue concentrations 4, 6

Linezolid: Excellent Gram-Positive Coverage with Superior Penetration

Linezolid has very high bioavailability and excellent tissue penetration, making it ideal for complicated skin and soft tissue infections, particularly MRSA. 1

• Oral preparation has very high bioavailability, allowing early IV-to-oral switch 1
• Achieves therapeutic concentrations in skin and soft tissue 1
• Demonstrates superior clinical cure rates (RR = 1.09) and microbiological cure rates (RR = 1.17) compared to vancomycin for MRSA infections 1

Carbapenems: Broad-Spectrum with Good Penetration

Carbapenems show good tissue penetration into pancreas and other deep tissues. 1

• Effective for severe infections requiring broad coverage 1
• Should be reserved for critically ill patients due to resistance concerns 1

Piperacillin-Tazobactam: Moderate to Good Tissue Distribution

Widely distributed into tissues and body fluids, achieving 50-100% of plasma concentrations in most tissues. 7

• Penetrates intestinal mucosa, gallbladder, lung, and female reproductive tissues 7
• Tissue concentrations in skin range from 34.8-94.2 mg/L (tissue:plasma ratio 0.60-1.1) 7
• Muscle concentrations 9.4-23.3 mg/L (tissue:plasma ratio 0.18-0.29) 7
• Intestinal mucosa concentrations approximately 31 mg/L 7

Daptomycin: Excellent Skin and Soft Tissue Penetration

Achieves very good concentrations in skin and soft tissues, non-inferior to vancomycin for complicated skin infections. 1

• Particularly effective for MRSA skin and soft tissue infections 1
• Recommended dose: 10 mg/kg/dose IV once daily 1

Metronidazole: Good Anaerobic Coverage with Pancreatic Penetration

Shows good penetration into pancreas with bactericidal activity against anaerobes. 1

Antibiotics with POOR Tissue Penetration

Aminoglycosides

Aminoglycosides (gentamicin, tobramycin) fail to penetrate pancreas in sufficient concentrations to cover MIC of common bacteria in standard IV dosages 1

Vancomycin

• Poor CNS penetration in non-inflamed meninges 1
• Requires prolonged IV therapy compared to linezolid for skin infections 1

Clinical Considerations

Peripheral Vascular Disease

Peripheral vascular disease, but not diabetes per se, limits antibiotic delivery and penetration to infected foot tissues. 1

• Revascularization should be pursued when possible 1
• Even in ischemic limbs, antibiotics remain important for preventing infection spread 1

Route of Administration

Oral fluoroquinolones (ciprofloxacin, levofloxacin, ofloxacin) and clindamycin have excellent gastrointestinal absorption and bioavailability, making them suitable alternatives to IV therapy once clinical stability is achieved 1