{"id":"tobramycin-trough","name":"Tobramycin (Trough)","shortName":"Tobramycin trough","aliases":["Tobramycin Level, Trough","Tobramycin, Trough","Tobramycin Trough","Tobramycin Trough Level"],"abbreviations":[],"loinc":[{"code":"4059-2","primary":true},{"code":"22752-0","primary":false}],"specimen":"serum-or-plasma","units":[{"ucum":"ug/mL","display":"µg/mL"},{"ucum":"mg/L","display":"mg/L"},{"ucum":"umol/L","display":"µmol/L"}],"referenceRanges":[{"population":"Adults","low":null,"high":2,"unit":"ug/mL","unitDisplay":"µg/mL","note":"Quest prints 1.0–2.0 mg/L (the same as µg/mL) for a trough drawn just before the next dose. Only the upper limit is shown here, because a lower trough is not a concern and once-daily (extended-interval) regimens aim for a very low trough. FDA labeling says rising troughs above 2 mcg/mL may indicate that the drug is accumulating, and kidney harm is more likely if troughs do not fall below 2.","sources":[{"title":"Tobramycin, Trough (test code 8577)","url":"https://testdirectory.questdiagnostics.com/test/test-detail/8577/tobramycin-trough?cc=MASTER","publisher":"Quest Diagnostics"},{"title":"Tobramycin injection prescribing information","url":"https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=ac8134d9-a726-4508-b8b9-a536ef17243d","publisher":"DailyMed, National Library of Medicine"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The lowest tobramycin level in your blood, taken just before your next dose, used to check the antibiotic clears well and does not build up.","url":"https://bloodtesttracker.com/markers/tobramycin-trough","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}