ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryApproximately 50 million women use oral contraceptives (OC). Studies and case reports demonstrate that OC failure may be caused by rifampin, anticonvulsant drugs, and possibly some antibiotics. Contraceptive steroids may interfere with the metabolism of the and the glucocorticoids. Future investigation will document the clinical significance of other OC interactions as well as give rise to new interactions.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryA comparative bioavailability study of carbamazepine (CBZ) in tablets and a syrup preparation was carried out in six volunteers, using a crossover design. Plasma and saliva samples were collected at appropriate times, and the plasma specimens were analyzed by high performance liquid chromatography for concentrations of CBZ and its epoxide metabolite (CBZ-EP). Analysis of the data showed that the preparations were equally bioavailable, although absorption was faster from the syrup and gave higher maximum plasma levels of CBZ. In other respects the preparations were pharmacokinetically equivalent. Analysis of simultaneous plasma CBZ and CBZ-EP concentration-time data by iterative curve fitting to a one-compartment linear model permitted the calculation of elimination kinetic parameters of the CBZ-EP; the mean elimination half-life was 6.9 ± 2.7 h. Failure of the salivary CBZ concentrations soon after drug intake to correlate with simultaneous plasma CBZ levels rendered the salivary data useless for bioavailability comparison, but prompted a further study of salivary CBZ levels.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryDuring a carbamazepine (CBZ) relative bioavailability study involving tablets and a syrup preparation, salivary drug concentrations appeared disproportionately high relative to simultaneous plasma drug concentrations in the first 2–3 h after oral drug intake. This raised the suspicion of contamination of saliva by retention of drug in the mouth. In a separate study CBZ was retained in the mouth in tablet form (whole or crushed) or in syrup, for only 5 s before being spat out, and the mouth was carefully rinsed. Despite this, measurable salivary concentrations, sufficient to cause substantial error if extrapolated to simultaneous plasma drug concentrations, were present for at least 2 h after drug administration. CBZ in these studies disappeared from saliva with an apparent mean half-life of 21.0 ± 4.8 min. This experience suggests that, in therapeutic drug monitoring, salivary CBZ concentrations for at least 2 h after dosage may lead to invalid conclusions about simultaneous plasma CBZ concentrations.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryThe performance of the enzyme multiplied immunoassay technique (EMIT) in the measurement of total and free plasma carbamazepine (CBZ) levels was assessed in 140 clinical specimens and compared with a reference high pressure liquid chromatography (HPLC) technique. Free drug was measured in plasma filtrates obtained by the Free Level system. Both total and free CBZ levels as determined by EMIT correlated strongly with corresponding HPLC values (r = 0.88 and 0.92, respectively). Plasma CBZ concentrations, however, were higher by EMIT than by HPLC. The degree of CBZ overestimation by EMIT was relatively small (about 14%) in whole plasma but quite considerable (35% on average) in the filtrates. As a result, estimated values of free CBZ fraction were also higher for EMIT than for HPLC. Separate experiments in vitro suggested that the discrepancies between the two methods were due to cross-reaction of the EMIT reagent with the 10,11-epoxide metabolite of CBZ. The greater degree of overestimation for the free drug can be explained by the higher proportion of less protein-bound metabolite in the filtrates. These results need to be taken into account in the interpretation of free CBZ level data from laboratories using different techniques.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryBy intrapatient comparison at constant phenytoin (PHT) dose, the effect of carbamazepine (CBZ) comedication on PHT was studied in a group of 24 epileptic outpatients. In half of the patients with steady-state PHT plasma concentration, a significant increase of this concentration was noted after CBZ was added to their regimen. Twenty percent showed clinical manifestations of acute drug toxicity initially thought to be CBZ related. The mean PHT plasma concentration for the 12 patients (22.7 ± 5.64 μg/ml) as well as concentration/ dose ratio for PHT (4.61 ± 1.65 μg/ml plasma per mg/kg/day dose) was significantly higher (p < 0.001) with concomitant administration of CBZ than when PHT was given alone: PHT concentration, 12.54 ± 3.93 (μg/ml and PHT concentration/dose ratio, 2.52 ± 0.78 μg/ml plasma per mg/kg/day dose. Those patients with higher PHT plasma concentrations seem to be at higher risk of PHT toxicity due to CBZ comedication.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryExperience is reported with 41 patients taking perhexiline maleate for angina pectoris for periods of up to 70 months, while serum concentrations of the drug were monitored, and liver function tests and electromyographic tests were made before and during treatment. Severe side effects did not occur unless serum perhexiline levels were greater than 1.5 mg/L. The drug seems effective for prolonged dosage, and the monitoring of weight, liver function test results, and serum concentrations should prevent or reduce toxicity. A starting dose of 100 mg daily is recommended. The drug is not recommended for routine use in angina pectoris.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

SummaryMeasurement of whole blood and plasma levels of cyclosporin A (CsA) by radioimmunoassay in kidney transplant recipients receiving the drug showed that CsA concentrations in plasma increased nonlinearly when whole blood levels of the drug exceeded 1,000 ng/ml. At low plasma levels (<200 ng/ ml), most of the CsA in blood was in the nonplasma component, indicating that cellular elements have high affinity for CsA. Comparison of nonplasma CsA concentrations in two patients with hematocrit values of 32.5 and 35% showed that in the patient with a hematocrit of 35% the cellular associated drug was twice as great as that in the other patient, indicating that there may be significant differences in the cellular affinity of CsA in patients with similar hematocrits. Linear regression analysis of the cellular associated CsA versus plasma levels of the drug in a double-reciprocal plot showed a drug saturation capacity of 6,060 ng/ml in the nonplasma component of blood in the patient with a hematocrit of 35%. Similar analyses in the other patients indicated saturation capacities ranging from 4,750 to 10,400 ng/ml.

ISSN:0163-4356    

出版商:OVID    

年代:1985

数据来源: OVID