ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • pharmacokinetics  (25)
  • bioavailability  (7)
  • 42.65
  • NDE
  • Springer  (28)
  • 1980-1984  (28)
  • 1983  (28)
Collection
Publisher
  • Springer  (28)
Years
  • 1980-1984  (28)
Year
  • 1
    ISSN: 1432-1041
    Keywords: cimetidine ; intravenous infusion ; pharmacokinetics ; peptic ulcer ; duration of infusion ; acute dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The use of cimetidine administered by bolus intravenous injection to critically ill patients has been associated with serious cardiac arrhythmias, due presumably to high initial plasma concentrations. The aim of this study was to determine the range of infusion times of a single 200 mg dose of cimetidine which would avoid high initial drug concentrations while maintaining a duration of effective concentrations no less than that resulting from bolus injection. Computer simulations of both maximum plasma cimetidine concentrations and duration of effective plasma cimetidine concentrations versus duration of infusion were based on mean pharmacokinetic date from 6 peptic ulcer patients who had received cimetidine 200 mg i.v. over 5 min. The simulations indicated that to reduce maximum plasma cimetidine concentrations by at least 50%, while maintaining the duration of effective plasma concentrations, the infusion time should be at least 30 min and no longer than 4.5 h. The validity of the simulations was subsequently tested in 4 of the patients, who received cimetidine 200 mg i.v. over 30 min. The mean maximum plasma concentration for the 30 min infusion (4.57±0.53 µg/ml) was, as predicted, approximately half that corresponding to bolus administration in these patients (8.97±1.96 µg/ml). Moreover, the duration of effective concentrations for the infusion (1.43±0.28 h) was significantly greater than that for the 5 min infusion (1.21±0.31 h). We suggest that where an acute intravenous dose of cimetidine (200 mg) is indicated, it should be administered over at least 30 min rather than as a bolus.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 567-568 
    ISSN: 1432-1041
    Keywords: astemizole ; ethanol ; antihistamine ; pharmacodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of astemizole (10 mg daily for 7 days) on the kinetics and CNS depressant activity of ethanol have been examined in a double-blind cross-over study agonist placebo in 7 volunteers. There was no significant change in the elimination rate or AUC of the plasma ethanol concentration-time curve after astemizole. Central nervous system effects of ethanol as monitored by visual analogues of sedation, visual discrimination, pursuit rotor and reaction time were also unaffected by astemizole pretreatment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1041
    Keywords: theophylline ; asthma ; children ; sustained-release ; diurnal ; absorption ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The absolute oral bioavailability of a sustained release theophylline tablet (Nuelin-SR250), given 12 hourly was determined in 14 asthmatic children aged 5 to 13 years. In 4 of the patients, mean bioavailability of the fourth dose was 38.9±8.4% and that of the sixth dose was 67.9±25.9% (p〈0.05) in the other ten patients. This suggests steady-state had not been achieved after four doses. In the initial study with 9 patients, a significant diurnal variation in predose plasma theophylline concentrations was observed, as the mean morning predose concentrations were 2.9 fold greater than the mean evening predose concentrations (p〈0.005). Dual peak plasma concentrations occurred in 5 out of the 9 patients. The mechanism of this diurnal variation was investigated in a further 5 asthmatic children (10.8 years ±1.6). Morning and night steady-state plasma theophylline concentrations during a continuous intravenous infusion of aminophylline were not different (14.9±5.3 mg/l vs. 15.6±5.9 mg/l), demonstrating that there was no diurnal variation in the plasma clearance of theophylline. The diurnal variation in predose concentrations with Neulin-SR250 was confirmed with the morning concentrations again being 2.6 fold greater than those in the evening. However, bioavailability was not significantly different for day (09.00–21.00) and night (21.00–09.00) dosing intervals after doses 6 and 7 respectively of Nuelin-SR250. The plasma concentration versus time profiles suggested that the diurnal variation in predose concentrations was due to slower absorption of the evening dose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 349-352 
    ISSN: 1432-1041
    Keywords: diltiazem ; pharmacokinetics ; intravenous dose ; oral dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The kinetic profile of diltiazem, a novel calcium antagonist, was studied in 12 volunteers following oral (60 mg) and intravenous (15 mg) administration. After i.v. administration biphasic elimination was observed, with a distribution half-life of 0.3±0.2 h and an elimination half-life of 3.1±1.0 h; the apparent volume of distribution was 5.3±1.71/kg and the total clearance was 1.28±0.48 l/kg/h. After the oral dose the elimination phase had a half-life of 3.2±1.3 h. The absolute bioavailability of diltiazem ranged from 24 to 74% (mean 42±18%). The interindividual variation may be explained by a variable first pass effect.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 11 (1983), S. 183-187 
    ISSN: 1573-8744
    Keywords: nonlinear regression ; parameter estimation ; invariance ; transformation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It is shown that when one nonlinear regression model is a reparametrization of a second model, the parameter estimates, and their standard errors, for one model can be obtained directly from those obtained from fitting the other model.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-8744
    Keywords: naltrexone ; controlled release ; pharmacokinetics ; gas chromatography ; biodegradable copolymer delivery system ; release rate quantitationin vivo ; Loo-Riegelman method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Naltrexone release rates from a controlled release delivery system have been quantitated over a time period greater than one month in the monkey. The method requires calibration of the pharmacokinetic parameters of each monkey utilizing an intravenous bolus dose and assay of unchanged naltrexone levels in plasma as a function of time after dosing. Also required are periodic plasma levels of unchanged naltrexone obtained subsequent to administration of the delivery system. Release rates are then calculated as well as the total amount released. Application of the methodology to a biodegradable copolymer naltrexone delivery system in three monkeys showed an initial release rate of 3– 8% of the dose per day over the first 3– 5 days followed by a slow, rather constant release rate of 1– 3% per day from day 5 to the time of the last measurable plasma sample (36– 43 days). Comparison of alternative calculation methods using both experimental and simulated plasma naltrexone data verified the accuracy of the release rate calculations. The sum of the calculated total amount of naltrexone released plus the assayed amount remaining in the delivery system after removal from the animal accounted for 91– 94% of the administered dose in the two monkeys in which complete data were obtained.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 521-524 
    ISSN: 1432-1041
    Keywords: sotalol ; beta-adrenoceptor antagonist ; pregnancy ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Sotalol, a beta-adrenoceptor blocking drug, was administered to 6 healthy pregnant volunteers between 32–36 weeks gestation and when at least 6 weeks post-partum. On both occasions, each volunteer was given sotalol 100 mg intravenously and 400 mg orally in randomised order with at least a 1 week washout period between. Plasma samples were analysed for sotalol using a fluorometric method and the pharmacokinetic profiles investigated. The systemic clearance of sotalol was significantly greater in the antenatal period (2.4±0.3 ml/min/kg) than in the post-natal phase (1.5±0.1 ml/min/kg). The apparent volume of distribution was similar in the two periods: the elimination half-life was 6.6±0.6h ante-natally and 9.3±0.7h post-natally after intravenous drug but the trend for faster elimination was not significant. The elimination half-life after oral administration (about 10h) and bioavailability (about 90%) were not altered significantly by pregnancy. It is suggested that the more rapid clearance of sotalol in pregnancy may be due to increases in renal plasma flow and glomerular filtration rate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 549-556 
    ISSN: 1432-1041
    Keywords: dibromosulfophthalein ; pharmacokinetics ; plasma levels ; urinary excretion ; biliary excretion ; biliary fistula ; enterohepatic circulation ; hepatic transport test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of dibromosulfophthalein (DBSP), the 3,6-dibromo analogue of BSP, was studied in 7 patients with a biliary fistula, 52 h after cholecystectomy, and in 6 gynaecological patients with an indwelling urethral catheter, following extirpation of the uterus i.e. with an intact enterohepatic circulation. Plasma protein binding determined by ultrafiltration was 98–99% up to a concentration of 700 µg/ml. After an intravenous bolus injection of DBSP 5 mg/kg, a biexponential plasma decay was found in both groups, with a rapid initial t1/2 of 2–6 min and a slow secondary phase of 33–109 min (mean 66 min) in the cholecystectomy patients, and 10–30 min (mean 19 min) in the gynaecological patients. The biliary excretion rate varied considerably between the patients and was highly correlated with bile flow. Biliary output amounted to a maximum of 86% of the dose in 24 h. The excretion rate curves showed ascending and descending phases, the mean terminal t1/2 being 65 min. Urinary excretion was 3–11% of the dose in 8 h in the gynaecological patients (mean 6%) and 6–31% in the cholecystectomy group (mean 16%). Renal clearance of unbound DBSP was about ten-times greater than the glomerular filtration rate, which indicates tubular secretion. A two compartment model with elimination from the peripheral and central compartments was selected because of these data. Analysis of the plasma-disappearance curves indicated an initial plasma clearance of 500–600 ml/min, which suggests that hepatic uptake will be very dependent on flow. Steady state (biliary) clearance was about 400 ml/min in the gynaecological group and approximately half that in the cholecystectomy patients; V1 tended to be higher and V2 to be lower in the latter group. It is concluded that biliary excretion rate of DBSP in patients with a biliary fistula is probably depressed by the postoperative bile drainage and the lack of enterohepatic cycling of bile salts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 813-818 
    ISSN: 1432-1041
    Keywords: dihydroergotamine ; dextran 70 ; pharmacokinetics ; radioimmunoassay ; drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of subcutaneous dihydroergotamine (DHE) with or without dextran 70 infusion was evaluated in a single- and multiple-dose study in 30 patients. Radioimmunoassay was used to measure plasma DHE and the anthrone method to determine the dextran concentration. In the single-dose study no significant interaction between DHE and dextran was noted with respect to their plasma levels. The absorption of s.c. DHE was rapid and the disappearance curve followed a biphasic pattern, t0.5 α being 1.4 and 2.0 h, t0.5 β 22 and 21 h for DHE and DHE/dextran 70, respectively. In the multi-dose study the trough level of DHE initially had a tendency to rise, in accordance with simulated plasma concentration curves. DHE trough levels were about 0.5 ng/ml and were well above the assumed minimum effective value to induce venoconstriction (0.06 ng/ml). Dextran concentrations were significantly higher when DHE was co-administered, possibly, due to changes in plasma volume. It is concluded that DHE 0.5 mg s.c. twice daily will give an adequate plasma concentration and that there was no important interaction between it and infused dextran 70.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 77-80 
    ISSN: 1432-1041
    Keywords: meptazinol ; pharmacokinetics ; multiple dosing ; plasma protein binding ; analgesic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of meptazinol (Meptid®) have been studied in nine male volunteers after single and multiple oral administration of 200 mg tablets and also after a single 25 mg intravenous dose. Plasma concentrations of meptazinol were determined by HPLC using fluorescence detection. Drug absorption after oral dosage was rapid, peak plasma concentrations being reached between 0.25 and 2 h after drug administration. Subsequent elimination proceeded in an apparently mono-exponential fashion with a half-life of 2 h, although after intravenous dosage there was evidence of an initial rapid distributive phase. The mean total plasma clearance was 2.21/min and the mean apparent volume of distribution (Vdβ) was 4.99 l/min. The bioavailability ranged from 1.9 to 18.5% (mean=8.7%) and was related to the rate of absorption. Multiple dosing, 6-hourly for 3 days, did not produce any accumulation above that predicted from a single dose. Plasma protein binding of the drug was 27.1% and did not vary over the therapeutic concentration range of 25 to 250 ng/ml.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...