Therapeutic drug monitoring
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Comparative Study
Sampling times for monitoring tacrolimus in stable adult liver transplant recipients.
The aim of this study was to determine the most informative sampling time(s) providing a precise prediction of tacrolimus area under the concentration-time curve (AUC). Fifty-four concentration-time profiles of tacrolimus from 31 adult liver transplant recipients were analyzed. Each profile contained 5 tacrolimus whole-blood concentrations (predose and 1, 2, 4, and 6 or 8 hours postdose), measured using liquid chromatography-tandem mass spectrometry. ⋯ The highest sensitivity index was determined to be 4.9 hours postdose at steady state, suggesting that this time point provides the most information about the AUC(0-12). The results from limited sampling strategies and sensitivity analysis supported the use of a single blood sample at 5 hours postdose as a predictor of both AUC(0-6) and AUC(0-12). A jackknife procedure was used to evaluate the predictive performance of the model, and this demonstrated that collecting a sample at 5 hours after dosing could be considered as the optimal sampling time for predicting AUC(0-6).
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Administration of fluvoxamine with concomitant benzodiazepines is common in clinical situations. This study investigated the effects of the coadministration of fluvoxamine on plasma concentrations of etizolam and evaluated the effects of various fluvoxamine doses on drug interactions with etizolam. Subjects were 18 Japanese outpatients concomitantly treated with fluvoxamine before or after monotherapy with etizolam. ⋯ Although the sleepiness of the subjects was evaluated using the Stanford Sleepiness Scale, no changes in sleepiness were found between the etizolam-monotherapy and the fluvoxamine-concomitant states. Of the 12 subjects treated concomitantly with fluvoxamine at 25 mg, 2 subjects received fluvoxamine at a dose increased up to 150 mg, and another received fluvoxamine at a dose increased up to 200 mg. They showed an increase in the plasma concentrations of etizolam in a fluvoxamine dose-dependent manner; more particularly, the increased dose of fluvoxamine (150 mg and 200 mg) resulted in about a twofold variation in plasma concentrations of etizolam.
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Comparative Study
Midazolam therapeutic drug monitoring in intensive care sedation: a 5-year survey.
During a 5-year period, 1997 to 2002, therapeutic drug monitoring of midazolam plasma concentrations in combination with the level of sedation as assessed by the Ramsay sedation scale was performed in 648 critically ill patients requiring artificial ventilation. In a subgroup of 189 patients sepsis-related organ failure assessment procedure was additionally performed. A total number of 3354 samples were analyzed. ⋯ To achieve a certain levels of sedation, significantly lower midazolam infusion rates as well as plasma concentrations were required as the patients age increased. No significant sex-related differences could be observed for any pharmacologic parameter obtained in this study. Our findings suggest that midazolam therapeutic drug monitoring might be a useful tool to individualize midazolam therapy, especially in critically ill patients developing organ dysfunction and requiring long-term sedation to minimize the risk of drug accumulation and excessive sedation.