Table 9.

Final concentrations of antibiotic lock solutions used for the treatment of catheter-related bloodstream infection.

Antibiotic and dosage	Heparin or saline, IU/mL	Reference(s)
Vancomycin, 2.5 mg/mL	2500 or 5000	[100, 275]
Vancomycin, 2.0 mg/mL	10	[275]
Vancomycin, 5.0 mg/mLa	0 or 5000	[276, 277]
Ceftazidime, 0.5 mg/mL	100	[123]
Cefazolin, 5.0 mg/mL	2500 or 5000	[100, 277]
Ciprofloxacin, 0.2 mg/mLb	5000	[130]
Gentamicin, 1.0 mg/mL	2500	[100]
Ampicillin, 10.0 mg/mL	10 or 5000	[275]
Ethanol, 70%c	0	[131]

NOTE. These antibiotic lock solutions will not precipitate at the given concentrations. Cefazolin is the preferred agent for treatment of methicillin-susceptible staphylococci, and vancomycin is the preferred agent for treatment of methicillin-resistant staphylococci. Ceftazidime, gentamicin, or ciprofloxacin can be used for treatment of gram-negative microorganisms. Ampicillin is the preferred agent for infections due to ampicillin-sensitive Enterococcus species, and vancomycin is the preferred agent for treatment of ampicillin-resistant enterococci other than vancomycin-resistant enterococci. The use of an ethanol lock can be considered for the treatment of a mixed gram-positive and gram-negative infection. NA, not applicable.

^aVancomycin at 5 mg/mL is more efficacious than at 1 mg/mL in eradicating staphylococci embedded within biofilm [276]. A precipitate appears when mixing a 10 mg/mL of vancomycin with 10,000 IU/mL of heparin; however, by agitating the solution for ~10 s, the precipitation resolves and the solution remains precipitate-free for 72 h at 37°C (355). The lock solution in 2500 IU/mL heparin can be made as follows: using vials containing 50 mg/mL of vancomycin in water, remove 2 mL and dilute in 8 mL 0.9% NaCl, resulting in 10 mg/mL of vancomycin. Place 1 mL of 5000 IU/mL heparin in a glass test tube and mix with 1 mL of the 10-mg/mL vancomycin solution (B. J. Rijnders and R. Mathot, personal communication).

^bThe maximum concentration of ciprofloxacin is limited because of precipitation at higher concentrations.

^cAn in-vitro study demonstrated the compatibility of ethanol 70% and silicone or polyetherurethane catheters [278].