Tobramycin Unit Conversion

Tobramycin is an aminoglycoside antibiotic used in the treatment of infections caused by Pseudomonas aeruginosa, Proteus species, E. coli, Klebsiella, Serratia, Citrobacter, Staphylococcus aureus, Enterobacter and other microorganisms. Tobramycin’s toxic effect is produced by interfering with ribosomal protein synthesis. Tobramycin undergoes very little, if any, metabolization and is, therefore, eliminated as the parent drug by glomerular filtration. The half‑life of tobramycin in serum or plasma correlates closely with renal function and thus is quite variable between individuals and within one individual over time. Serum or plasma tobramycin concentration is also impacted by mode of administration, the volume of extracellular fluid, the duration of the treatment and physiological changes during the illness and therapy. The therapeutic range of tobramycin should be measured at peak as well as trough concentrations. In patients with pre‑existing renal damage or those to whom tobramycin has been administered for prolonged periods or in doses above the therapeutic range, hearing impairment and/or nephrotoxicity may develop. Therefore, monitoring of peak and trough tobramycin serum or plasma levels is critical in the prevention of these serious complications with the adjustment of dosage administration as indicated.

Equivalent diagnostic technologies have shown that in most adults, a peak therapeutic response is achieved with tobramycin concentrations in the 6‑10 μg/mL (12.8‑21.4 μmol/L) range and trough concentrations in the 0.5‑2.0 μg/mL (1.1‑4.3 μmol/L) range. A peak therapeutic range is suggested for optimal antimicrobial effectiveness. Concentrations above the therapeutic range for a prolonged period of time or in patients with pre‑existing renal impairment can cause nephrotoxicity and/or hearing impairment. Elevated or increasing trough levels are an indication of drug accumulation due to renal impairment. Both peak and trough levels should be monitored to ensure prevention of serious complications associated with drug dosage.