Gentamicin, Peak, Plasma or Serum

Gent Peak/GENTP - NOCO

1 mL plasma from Green top (Lithium Heparin)

0.5 mL
Note: For neonate requirements see Neonate Minimum Blood Volumes

1 ml serum from Serum Gel or Red Top

• Specimen for a peak level should be drawn 30 minutes after completion of infusion of an intravenous dose or 60 to 90 minutes after an intramuscular dose of gentamicin.
• Indicate exact time drug was started, exact time infusion was completed in label comments (i.e. IV 1200 /1230).  If the drug will be administered by intramuscular injection, indicate time of injection in label comments (i.e. IM 1300).

Temperature	Time
Refrigerated	5 days

 

Gross hemolysis

Monday through Sunday; Continuously

Same day

            5.0 – 10.0 µg/mL
           Critical value (automatic call-back): >12.0 µg/mL

Gentamicin is used in the treatment of serious infections involving aminoglycosidesensitive organisms. Monitoring gentamicin concentration in serum or plasma, along with careful clinical assessment, is the most effective means of ensuring adequate therapy. Gentamicin concentration correlates better with antibacterial activity than dosage. A standard dose of gentamicin does not always yield a predictable concentration because drug concentration depends on patient’s volume of distribution and on drug elimination. The mode of administration, the volume of extracellular fluid, renal retention, and physiological change influence these factors during therapy. Gentamicin has a narrow range of safe and effective concentration. Exposure to high concentrations for a prolonged period may cause renal impairment or ototoxicity. Patients with impaired renal function should be monitored closely while on gentamicin therapy because nephrotoxicity caused by gentamicin may be difficult to distinguish from symptoms of underlying renal disease.