Test Catalog

Test ID: PLAZO    
Plazomicin, Plasma

Useful For Suggests clinical disorders or settings where the test may be helpful

An aid to achieving the desired plasma concentrations of plazomicin

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Plazomicin is an aminoglycoside engineered to overcome the most prevalent aminoglycoside-modifying enzymes, which are a common aminoglycoside-resistance mechanism. Plazomicin levels are intended to be used by clinicians to support clinical decision-making in guiding appropriate dosage adjustments for patients on plazomicin therapy. The safety and effectiveness of plazomicin treatment in an individual patient should ultimately be based on clinical response.


The trough reference range represents plazomicin minimum (trough) concentrations associated with a reduced risk of nephrotoxicity. However, some patients with plasma trough concentrations outside the trough reference range may achieve a satisfactory response.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Complicated urinary tract infections (cUTI):

Trough Reference Range: <3 mcg/mL

(Trough=30 min before second dose, and 30 min before subsequent doses as appropriate)

Interpretation Provides information to assist in interpretation of the test results

The plazomicin drug package insert should be consulted for information regarding the utilization of plazomicin concentrations and guidance for therapeutic drug monitoring (TDM).


For patients with complicated urinary tract infections (cUTI) with creatinine clearance (CLcr) values of 15 and higher, but less than 90 mL/min, monitoring of plazomicin plasma trough concentrations is recommended to avoid potentially toxic levels. For this subset of patients, it is recommended that the sample for the plazomicin minimum (trough) concentration measurement be drawn within approximately 30 minutes before administration of the second dose of plazomicin.


Plazomicin dosage should be adjusted to avoid trough levels above 3 mcg/mL. Modeled plazomicin trough concentrations from 377 patients with cUTI in Phase 2 and Phase 3 trials have been determined to range from 0.1 to 3.3 mcg/mL (5-95 percentile range) with a median and geometric mean of 0.8 and 0.7 mcg/mL, respectively. Measured plazomicin trough concentrations by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for 274 trough samples in the Phase 3 Study ACHN-490-009 resulted in similar values (0.2 to 5.7 mcg/mL 5-95 percentile range; 1.1 mcg/mL median and geometric mean). For effective treatment, some patients may require plasma levels outside of these ranges. Therefore, the expected ranges are provided as guidelines, and individual patient results should be interpreted with the aid of the dosage adjustment algorithms in the plazomicin drug package insert and in the context of the patient's other clinical signs and symptoms.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. McKinnell JA: Improved outcomes with plazomicin compared with colistin in patients with bloodstream infections caused by carbapenem-resistant enterobacteriaceae (CRE): Results from CARE study. Poster 1853 IDWeek October 4-8, 2017. San Diego, CA

2. Golan Y et al. Improved outcomes at late follow-up with plazomicin compared with meropenem in patients with complicated urinary tract infections (cUTI) or acute pyelonephritis in the EPIC study. Poster 1859 IDWeek October 4-8, 2017. San Diego, CA

3. Cloutier, D: Plazomicin versus meropenem for complicated urinary tract infection and acute pyelonephritis: diagnosis-specific results from the phase 3 EPIC study. Poster 1855 IDWeek October 4-8, 2017. San Diego, CA

4. Zhanel GG: Comparison of the next-generation aminoglycoside plazomicin to gentamicin, tobramycin, and amikacin. Expert Rev Anti Infect Ther 2012;10(4):459-73

5. Begg EJ: A suggested approach to once-daily aminoglycodise dosing. Br J Clin Pharmac 1995;39:605-609