[Usefulness of repeated measurement of plasma levels of gentamycin].

We monitored plasma levels of gentamycin in 28 patients being treated for different infectious processes. The mean age was 53.7 years. Drug dose and administration was determined by the treating physician, without knowledge of plasma levels. Peak and through levels were measured by RIA after the third and 7th dose. No patient had adequate therapeutic levels throughout the treatment period and 6 were therapeutic failures. Patients with renal insufficiency frequently had toxic plasma levels. Monitoring gentamycin plasma levels is recommended for all patients receiving the drug, especially those with renal insufficiency or therapeutic failure.