Stability of rifampin in plasma: consequences for therapeutic monitoring and pharmacokinetic studies.
Author(s): Le Guellec C, Gaudet ML, Lamanetre S, Breteau M
Publication: Ther Drug Monit, 1997, Vol. 19, Page 669-74
PubMed ID: 9421109 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the effects of storage and preservation with ascorbic acid on concentrations of rifampin in spiked and patient plasma.
Conclusion of Paper
Spiked rifampin was stable in plasma stored for 2 h at room temperature unless the plasma was stabilized with ascorbic acid in which it was stable for 12 h. When specimens were stored at -20 degrees C, spiked rifampin was stable in plasma stabilized with ascorbic acid but declined rapidly when ascorbic acid was not present. In patient plasma (unspiked), a similar but smaller decrease in rifampin concentration was observed when specimens with or without ascorbic acid were stored at room temperature or -20 degrees C.
Studies
-
Study Purpose
The purpose of this study was to determine the effects of storage and preservation with ascorbic acid on concentrations of rifampin in spiked and patient plasma.
Summary of Findings:
When plasma spiked with 1 mg/L rifampin was stored at room temperature, measured rifampin concentrations decreased significantly beginning after 4 h of storage, but the loss was partially attenuated in the presence of ascorbic acid such that significant loss was observed only after 24 h of storage. When plasma spiked with 10 mg/L rifampin was stored at room temperature, significant declines in rifampin concentration were first noted after 12 h in the absence of ascorbic acid and after 24 h in the presence of ascorbic acid. Regardless of spiked rifampin concentration, when plasma was stabilized with ascorbic acid, storage of plasma at -20 degrees C for 2 weeks did not affect rifampin concentrations, but in the absence of ascorbic acid, rifampin levels declined rapidly (within 1 to 3 days). In patient plasma, a similar but smaller decrease in rifampin concentration was observed when specimens were stored at room temperature or -20 degrees C with or without ascorbic acid.
Biospecimens
Preservative Types
- None (Fresh)
- Other Preservative
- Frozen
Diagnoses:
- Not specified
- Other diagnoses
Platform:
Analyte Technology Platform Small molecule HPLC Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature Room temperature
-20 degrees C
Storage Storage duration 0 h
1 h
2 h
4 h
8 h
12 h
24 h
3 days
4 days
5 days
7 days
8 days
2 weeks
Preaquisition Other drugs Rifampin
Biospecimen Aliquots and Components Biospecimen components 1 mg/L rifampin
10 mg/L rifampin
Biospecimen Preservation Type of fixation/preservation Ascorbic acid
Frozen
None (fresh)
Preaquisition Diagnosis/ patient condition Tuberculosis