       Document 0133
 DOCN  M9620133
 TI    High-performance liquid chromatographic evaluation of the effect of heat
       treatment on trimethoprim and sulfamethoxazole stability in serum.
 DT    9602
 AU    Moore KH; Brouwer KL; Division of Pharmaceutics, School of Pharmacy,
       University of; North Carolina, Chapel Hill 27599-7360, USA.
 SO    Ther Drug Monit. 1995 Aug;17(4):356-60. Unique Identifier : AIDSLINE
       MED/96103434
 AB    Heat treatment of patient samples is utilized as a method to decrease
       the risk of accidental transmission of human immunodeficiency virus
       (HIV). Heat treatment has been reported to affect the outcome of drug
       analysis. In this study, the effects of heat treatment (56 degrees C for
       5 h) and storage for 2 months at -20 degrees C on the stability of
       trimethoprim (TMP) and sulfamethoxazole (SMX) at three different
       concentrations in serum (10/100, 1/20, and 0.1/5 microgram/mL) each were
       evaluated. Simultaneous determination of TMP, SMX, and sulfamethazine
       (SMeth), the internal standard, in serum was performed by a
       reversed-phase high-performance liquid chromatographic (HPLC) procedure
       with isocratic elution and ultraviolet detection. The peak/height ratios
       (PHRs) for each sample from untreated and heat-treated groups were
       compared. No statistically significant differences were found between
       untreated and heat-treated groups for TMP. Heat treatment decreased the
       PHR for SMX at 100 micrograms/ml concentration (p = 0.042) and increased
       the PHR for SMX at 20 micrograms/ml concentration (p = 0.049). These
       marginal differences are unlikely to be significant. Storage of samples
       for 2 months at -20 degrees C had no statistically significant effect on
       sample PHRs. Thus, heat treatment of serum does not alter clinical
       interpretation of TMP and SMX at clinically relevant concentrations and
       may protect laboratory workers from accidental HIV exposure.
 DE    Anti-Infective Agents/BLOOD/THERAPEUTIC USE  Anti-Infective Agents,
       Urinary/BLOOD  Chromatography, High Pressure Liquid  Drug Stability
       Freezing  *Heat  Human  Sulfamethoxazole/*BLOOD/THERAPEUTIC USE
       Support, Non-U.S. Gov't  Trimethoprim/*BLOOD/THERAPEUTIC USE  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

