Study Objective: In critically ill patients, adequacy of early antibiotic exposure has been incompletely evaluated. This study characterized factors associated with inadequate cefepime exposure in the first 24 h of critical illness.
Design: Prospective cohort study.
Background: The class of antibiotics known as β-lactams are a commonly used due to their effectiveness and safety. Therapeutic drug monitoring has been proposed but requires an accurate assay along with well-characterized preanalytic stability, as β-lactams are known to be relatively unstable.
Methods: A high-throughput LC-MS/MS assay validation and stability study was performed for cefepime, meropenem, and piperacillin and tazobactam in serum.
Numerous methods for the measurement of tacrolimus and cyclosporine A involving traditional liquid chromatography tandem mass spectrometry (LC-MS/MS) have previously been described. The majority of these methods use solid-phase extraction, liquid-liquid extraction, or protein precipitation extraction with instrument run times greater than 15 s per sample. Continued demands in clinical labs for greater efficiency and throughput have put increased stress on traditional technologies such as high-performance liquid chromatography-ultraviolet detection (HPLC-UV) and traditional LC-MS/MS.
View Article and Find Full Text PDFAbuse of the stimulant cocaine (COC) is a common problem in the United States and elsewhere. The drug can be used either as the powder or as the free base (crack COC), and causes feelings of alertness and euphoria; both forms of COC are powerfully addictive. The assay described here is designed to detect and quantitate parent COC, its major metabolite benzoylecgonine, and a selection of metabolites that can provide specific information about sample validity (m-hydroxybenzoylecgonine), potential toxicity (norcocaine), route of administration (anhydroecgonine methyl ester), and co-utilization with ethanol (cocaethylene).
View Article and Find Full Text PDFMethadone is a synthetic opioid used to relieve pain, treat opioid withdrawal, and wean heroin addicts. Measurement of methadone and its major metabolite EDDP in urine is useful for assessing compliance with addiction rehabilitation and pain management programs. This method quantitatively measures methadone and its metabolite EDDP in urine.
View Article and Find Full Text PDFCocaine (COC) is a potent CNS stimulant that is metabolized to benzoylecgonine (BE) and further metabolized to minor metabolites such as m-hydroxybenzoylecgonine (m-HOBE). COC is also metabolized to norcocaine (NC). Cocaethylene (CE) is formed when cocaine and ethyl alcohol are used simultaneously.
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