scholarly journals Comparison of the hypothalamic–pituitary–adrenal axis susceptibility upon single-dose i.m. depot versus long-acting i.v. triamcinolone acetonide therapy: a direct pharmacokinetic correlation

2006 ◽  
Vol 191 (2) ◽  
pp. 491-496 ◽  
Author(s):  
Getu Abraham ◽  
Fioralba Demiraj ◽  
Fritz Rupert Ungemach
Keyword(s):  
Triamcinolone Acetonide ◽  
Plasma Concentrations ◽  
Stress Axis ◽  
Dihydrogen Phosphate ◽  
Maximum Plasma ◽  
Acth Challenge ◽  
Cortisol Responses ◽  
Baseline Values ◽  
Cortisol Levels ◽  
Long Acting

The effects of single injections of glucocorticoid (GC) depot suspension and of long-acting GC were studied in conscious dogs. Both the depot suspension GC triamcinolone-16,17-α-acetonide (TAA) and the long-acting triamcinolone acetonide-21-dihydrogen phosphate (TAA-DHP) decreased basal and ACTH-stimulated cortisol levels and in a specific time-dependent way. Before treatment, all dogs had normal basal and peak cortisol responses to ACTH challenge (13–15 and > 120 nmol/l at 1 h respectively). Intravenous TAA-DHP reduced cortisol levels for 12 h, i.m. TAA reduced cortisol levels as of 1.5 h and the effect lasted for at least 4 weeks. Both treatments blunted the peak response to ACTH. ACTH elevated cortisol levels to or above baseline values within 10 days following TAA-DHP treatment, but the TAA treatment suppressed an ACTH response for at least 4 weeks. Kinetic analysis of both the preparations demonstrated rapid absorption (tmax, 0.6–1.5 h) and low maximum plasma concentrations (peak Cmax, 2.99–5.51 nmol/l) of the steroids; indeed, the terminal half-life of TAA-DHP (13.9 ± 1.3 h) was very much shorter than that of TAA (125.9 ± 15.8 h). In addition, the mean residence time differed very much (11 vs 160 h for TAA-DHP and TAA respectively), in line with a delayed elimination of the depot compared with the long-acting formulation. Application of these TAA formulations needs careful evaluation for their surprisingly different effects on endocrine stress axis activity.

scholarly journals Comparative Study on Pharmacokinetics of Four Long-Acting Injectable Formulations of Enrofloxacin in Pigs

2021 ◽  
Vol 7 ◽  
Author(s):  
Salah Uddin Ahmad ◽  
Jichao Sun ◽  
Fusheng Cheng ◽  
Bing Li ◽  
Safia Arbab ◽  
...  
Keyword(s):  
Comparative Study ◽  
High Performance ◽  
Pasteurella Multocida ◽  
Plasma Concentrations ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Reference Formulation ◽  
Time Curve ◽  
Drug Concentrations ◽  
Long Acting

A comparative study on pharmacokinetics of four long-acting enrofloxacin injectable formulations was investigated in 36 healthy pigs after intramuscular injection according to the recommended single dose @ 2.5 mg/kg body weight. The drug concentrations in the plasma were computed using high-performance liquid chromatography (HPLC) with fluorescence detection. WinNonLin5.2.1 software was used to analyze the experimental data and compared it under one-way ANOVA using SPSS software with a 95% confidence interval (CI). The main pharmacokinetic parameters, that is, the maximum plasma concentrations (Cmax), the time to maximum concentration (Tmax), area under the time curve concentration (AUCall) and Terminal half-life (T1/2) were 733.84 ± 129.87, 917.00 ± 240.13, 694.84 ± 163.49, 621.98 ± 227.25 ng/ml, 2.19 ± 0.0.66, 1.50 ± 0.37, 2.89 ± 0.24, 0.34 ± 0.13 h, 7754.43 ± 2887.16, 8084.11 ± 1543.98, 7369.42 ± 2334.99, 4194.10 ± 1186.62 ng h/ml, 10.48 ± 2.72, 10.37 ± 2.38, 10.20 ± 2.81, and 10.61 ± 0.86 h for 10% enrofloxacin (Alkali), 20% enrofloxacin (Acidic), Yangkang and control drug Nuokang® respectively. There were significant differences among Cmax, Tmax, and AUCall of three formulations compare with that of the reference formulation. No significant differences were observed among the T1/2 for tested formulations compare with the reference formulation. The pharmacokinetic parameters showed that the tested formulations were somewhat better compared to the reference one. The calculated PK/PD indices were effective for bacteria such as Actinobacillus pleuropneumoniae and Pasteurella multocida with values higher than the cut-off points (Cmax/MIC90≥10–12 and AUC/MIC90 ≥ 125). However, they were not effective against bacteria like Haemophilus parasuis, Streptococcus suis, E. coli, and Bordetella bronchiseptica where lower values were obtained.

Pharmacokinetics and Effects on Fibrinolytic and Coagulation Parameters of Two Doses of Recombinant Tissue-Type Plasminogen Activator in Healthy Volunteers

1986 ◽  
Vol 56 (01) ◽  
pp. 001-005 ◽  
Author(s):  
M Verstraete ◽  
C A P F Su ◽  
P Tanswell ◽  
W Feuerer ◽  
D Collen
Keyword(s):  
Healthy Volunteers ◽  
Plasminogen Activator ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
State Level ◽  
Compartment Model ◽  
Tissue Type ◽  
Maximum Plasma ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryPharmacokinetics and pharmacological effects of two intravenous doses of recombinant tissue-type plasminogen activator (rt-PA) (40 and 60 mg over 90 min) were determined in healthy volunteers. Mean maximum plasma concentrations were 1080 and 1560 ng/ml respectively. The steady state level during subsequent maintenance infusion of 30 mg over 6 h was 250 ng/ml. The pharmacokinetics of rt-PA showed a bi-exponential disappearance from plasma consistent with a 2-compartment model of t½α = 5.7 min, a t½β = 1.3 h and a total clearance of 380 ml/min.Mean fibrinogen levels at the end of the infusions of 40 mg or 60 mg rt-PA over 90 min, measured in thawed plasma samples collected on citrate/aprotinin, decreased to 74% and 57% of the preinfusion values respectively. Plasminogen fell to 55% and 48%, and α2-antiplasmin to 28% and 18% of initial values. No further decrease of these parameters was observed during the infusion of 30 mg rt-PA over 6 h. Only 2% of the preinfusion fibrinogen levels could be recovered as fibrinogen-fibrin degradation products. This moderate extent of systemic fibrinogenolysis is much less than that reported for therapeutic i.v. infusions of streptokinase.

Nimodipine pharmacokinetics after intraventricular injection of sustained-release nimodipine for subarachnoid hemorrhage

2021 ◽  
Vol 134 (1) ◽  
pp. 95-101 ◽  
Author(s):  
R. Loch Macdonald ◽  
Daniel Hänggi ◽  
Poul Strange ◽  
Hans Jakob Steiger ◽  
J Mocco ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Sustained Release ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
External Ventricular Drain ◽  
Plasma Concentrations ◽  
Intraventricular Injection ◽  
World Federation ◽  
Maximum Plasma ◽  
Clinical Trial Registration ◽  
Sustained Release Formulation

OBJECTIVEThe objective of this study was to measure the concentration of nimodipine in CSF and plasma after intraventricular injection of a sustained-release formulation of nimodipine (EG-1962) in patients with aneurysmal subarachnoid hemorrhage (SAH).METHODSPatients with SAH repaired by clip placement or coil embolization were randomized to EG-1962 or oral nimodipine. Patients were classified as grade 2–4 on the World Federation of Neurosurgical Societies grading scale for SAH and had an external ventricular drain inserted as part of their standard of care. Cohorts of 12 patients received 100–1200 mg of EG-1962 as a single intraventricular injection (9 per cohort) or they remained on oral nimodipine (3 per cohort). Plasma and CSF were collected from each patient for measurement of nimodipine concentrations and calculation of maximum plasma and CSF concentration, area under the concentration-time curve from day 0 to 14, and steady-state concentration.RESULTSFifty-four patients in North America were randomized to EG-1962 and 18 to oral nimodipine. Plasma concentrations increased with escalating doses of EG-1962, remained stable for 14 to 21 days, and were detectable at day 30. Plasma concentrations in the oral nimodipine group were more variable than for EG-1962 and were approximately equal to those occurring at the EG-1962 800-mg dose. CSF concentrations of nimodipine in the EG-1962 groups were 2–3 orders of magnitude higher than in the oral nimodipine group, in which nimodipine was only detected at low concentrations in 10% (21/213) of samples. In the EG-1962 groups, CSF nimodipine concentrations were 1000 times higher than plasma concentrations.CONCLUSIONSPlasma concentrations of nimodipine similar to those achieved with oral nimodipine and lasting for 21 days could be achieved after a single intraventricular injection of EG-1962. The CSF concentrations from EG-1962, however, were at least 2 orders of magnitude higher than those with oral nimodipine. These results supported a phase 3 study that demonstrated a favorable safety profile for EG-1962 but yielded inconclusive efficacy results due to notable differences in clinical outcome based on baseline disease severity.Clinical trial registration no.: NCT01893190 (ClinicalTrials.gov).

Design, Synthesis, Anticonvulsant Activity, Preclinical Study and Pharmacokinetic Performance of N-{[3-(4-chlorophenyl)-4-oxo-3, 4-dihydroquinazolin- 2-yl] methyl}, 2-[(2-isopropyl-5-methyl) 1-cyclo Hexylidene] Hydrazinecarboxamide

2019 ◽  
Vol 19 (1) ◽  
pp. 31-45
Author(s):  
Meena K. Yadav ◽  
Laxmi Tripathi
Keyword(s):  
Anticonvulsant Activity ◽  
Computational Study ◽  
Plasma Concentrations ◽  
Elimination Rate ◽  
Area Under The Curve ◽  
Preclinical Study ◽  
In Vivo Studies ◽  
Maximum Plasma ◽  
Seizure Models

Background: N-{[3-(4-chlorophenyl)-4-oxo-3, 4-dihydroquinazolin-2-yl] methyl}, 2-[(2- isopropyl-5-methyl) 1-cyclohexylidene] hydrazinecarboxamide QS11 was designed by computational study. It possessed essential pharmacophoric features for anticonvulsant activity and showed good docking with iGluRs (Kainate) glutamate receptor. Methods: QSAR and ADMET screening results suggested that QS11 would possess good potency for anticonvulsant activity. QS11 was synthesised and evaluated for its anticonvulsant activity and neurotoxicity. QS11 showed protection in strychnine, thiosemicarbazide, 4-aminopyridine and scPTZ induced seizure models and MES seizure model. QS11 showed higher ED50, TD50 and PI values as compared to the standard drugs in both MES and scPTZ screen. A high safety profile (HD50/ED50 values) was noted and hypnosis, analgesia, and anaesthesia were only observed at higher doses. No considerable increase or decrease in the concentration of liver enzymes was observed. Optimized QS11 was subjected to preclinical (in-vivo) studies and the pharmacokinetic performance of the sample was investigated. The result revealed that the pharmacokinetic performance of QS11 achieved maximum plasma concentrations (Cmax) of 0.315 ± 0.011 µg/mL at Tmax of 2.0 ± 0.13 h, area under the curve (AUC0-∞) value 4.591 ± 0.163 µg/ml x h, elimination half-life (T1/2) 6.28 ± 0.71 h and elimination rate constant was found 0.110 ± 0.013 h-1. Results and Conclusion: Above evidences indicate that QS11 could serve as a lead for development of new antiepileptic drugs.

scholarly journals Physiologically Based Pharmacokinetic Modelling of Cabozantinib to Simulate Enterohepatic Recirculation, Drug–Drug Interaction with Rifampin and Liver Impairment

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 778
Author(s):  
Bettina Gerner ◽  
Oliver Scherf-Clavel
Keyword(s):  
Hepatic Impairment ◽  
Kinase Inhibitor ◽  
Plasma Concentrations ◽  
Area Under The Curve ◽  
Enterohepatic Recirculation ◽  
Maximum Plasma ◽  
Good Precision ◽  
Physiologically Based Pharmacokinetic ◽  
Starting Point ◽  
Physiologically Based

Cabozantinib (CAB) is a receptor tyrosine kinase inhibitor approved for the treatment of several cancer types. Enterohepatic recirculation (EHC) of the substance is assumed but has not been further investigated yet. CAB is mainly metabolized via CYP3A4 and is susceptible for drug–drug interactions (DDI). The goal of this work was to develop a physiologically based pharmacokinetic (PBPK) model to investigate EHC, to simulate DDI with Rifampin and to simulate subjects with hepatic impairment. The model was established using PK-Sim® and six human clinical studies. The inclusion of an EHC process into the model led to the most accurate description of the pharmacokinetic behavior of CAB. The model was able to predict plasma concentrations with low bias and good precision. Ninety-seven percent of all simulated plasma concentrations fell within 2-fold of the corresponding concentration observed. Maximum plasma concentration (Cmax) and area under the curve (AUC) were predicted correctly (predicted/observed ratio of 0.9–1.2 for AUC and 0.8–1.1 for Cmax). DDI with Rifampin led to a reduction in predicted AUC by 77%. Several physiological parameters were adapted to simulate hepatic impairment correctly. This is the first CAB model used to simulate DDI with Rifampin and hepatic impairment including EHC, which can serve as a starting point for further simulations with regard to special populations.

ELIMINATION OF INFUSED ARGININE-VASOPRESSIN AND ITS LONG-ACTING DEAMINATED ANALOGUE IN RATS

1978 ◽  
Vol 78 (2) ◽  
pp. 179-186 ◽  
Author(s):  
DIANA GAZIS ◽  
W. H. SAWYER
Keyword(s):  
Arginine Vasopressin ◽  
Plasma Concentrations ◽  
Metabolic Clearance ◽  
Prolonged Infusion ◽  
Exponential Functions ◽  
Antidiuretic Effect ◽  
Long Acting ◽  
Deamino Arginine Vasopressin

SUMMARY Arginine-vasopressin (AVP) and deamino-arginine-vasopressin (dAVP) were infused into rats. When the concentrations of the two peptides were steady, the rate of clearance of AVP from the plasma was six times the rate of clearance of dAVP. Only 6% of the infused AVP was excreted unchanged in the urine, whereas approximately 100% of the dAVP was excreted. When the infusions were stopped, AVP disappeared from the plasma much more rapidly than dAVP. The plasma concentrations of the two peptides did not decay as simple exponential functions, suggesting that both AVP and dAVP entered a slowly exchanging compartment or compartments during prolonged infusion. These differences in the metabolic clearance of AVP and dAVP may well explain the prolonged antidiuretic effect of dAVP in rats.

Tonabersat, a Gap-Junction Modulator: Efficacy and Safety in Two Randomized, Placebo-Controlled, Dose-Ranging Studies of Acute Migraineceph

Cephalalgia ◽  
2009 ◽  
Vol 29 (2_suppl) ◽  
pp. 17-27 ◽  
Author(s):  
SD Silberstein ◽  
J Schoenen ◽  
H Göbel ◽  
HC Diener ◽  
AH Elkind ◽  
...  
Keyword(s):  
Adverse Events ◽  
North American ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Plasma Concentrations ◽  
International Study ◽  
Maximum Plasma ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Dose Ranging

Tonabersat is a novel benzopyran derivative that blocks the cortical spreading depression proposed to be associated with migraine attacks. The ability of single oral doses of 15, 25, 40 and 80 mg of tonabersat to relieve the symptoms of moderate to severe migraine was evaluated in 859 migraineurs enrolled in two dose-ranging, double-blind, randomized, placebo-controlled, parallel-group trials, one international and the other North American. In the international study, significantly more patients given tonabersat than given placebo experienced relief of headache pain at 2 h (15 mg, 36.8%; 40 mg, 40.7%), the principal efficacy variable, and at 4 h (40 mg, 63.0%) and complete abolition of headache at 4 h (40 mg, 34.3%). None of the primary or secondary efficacy variables indicated significant differences between tonabersat and placebo in the North American study. Tonabersat was generally well tolerated, with dizziness and nausea the most common side-effects. Serious adverse events were uncommon, and no patient withdrew from either study because of adverse events. These results suggest a possible interplay between tonabersat pharmacokinetics (the relatively long time required to reach maximum plasma concentrations) and patient characteristics (previous triptan exposure) in the management of acute migraine attacks. Based on the pharmacokinetics and actions on cortical spreading depression, tonabersat may have potential value in migraine prophylaxis.

scholarly journals Plasma profile of cimicoxib in sheep after oral administration at two different rates

2017 ◽  
Vol 20 (3) ◽  
pp. 535-538
Author(s):  
A. Di Salvo ◽  
M. Giorgi ◽  
H.K. Lee ◽  
C. Vercelli ◽  
F. Rueca ◽  
...  
Keyword(s):  
Oral Administration ◽  
Oral Treatment ◽  
Plasma Concentrations ◽  
Individual Variability ◽  
Maximum Plasma ◽  
Dose Rates ◽  
Single Oral Administration ◽  
Concentration Peak ◽  
Value Range ◽  
Slow Absorption

Abstract Sheep are often subjected to painful procedures and thus they need to be treated with analgesics. Nevertheless, knowledges about pharmacokinetic features of these drugs in this species are poor. The aim of this study was to evaluate plasma behaviour of cimicoxib in sheep after a single oral administration at two different dose rates (4 and 6 mg/kg). Maximum plasma concentrations of cimicoxib were equal to 273.78 (median value; range 189.00-567.32) and 565.01 (range 308.27-822.59) ng/mL after treatment with 4 and 6 mg/kg, respectively. The time of maximum concentration (Tmax) was achieved between 4 and 10 hours following treatment at the lower dose, and between 6 and 10 hours after the administration of the higher dose, with one sheep achieving the concentration peak at 0.75 hours. The slow absorption and the great individual variability in plasma concentration, probably due to ruminal effects, suggest that cimicoxib is not suitable for oral treatment in sheep.

Overt Glucocorticoid Excess Due to Inhaled Corticosteroid Therapy

PEDIATRICS ◽  
1988 ◽  
Vol 81 (3) ◽  
pp. 452-455
Author(s):  
Gregory A. Hollman ◽  
David B. Allen
Keyword(s):  
Triamcinolone Acetonide ◽  
Inhaled Corticosteroids ◽  
Therapeutic Option ◽  
Serum Cortisol ◽  
Hypothalamic Pituitary Adrenal Axis ◽  
Systemic Absorption ◽  
Hypothalamic Pituitary Adrenal ◽  
Adrenal Axis ◽  
Cortisol Levels ◽  
Pituitary Adrenal Axis

Inhaled corticosteroids have become an important therapeutic option in the treatment of childhood asthma. The preparations currently available for pediatric use (beclomethasone dipropionate and triamcinolone acetonide) do not, in general, cause significant hypothalamic-pituitary-adrenal axis suppression and physical signs of glucocorticoid excess have not been described with their use. We report an 8-year-old girl with asthma in whom obesity, hirsutism, and growth retardation developed during treatment with inhaled triamcinolone acetonide alone. Laboratory studies showed suppression of endogenous cortisol production but did not demonstrate suppression of the hypothalamic-pituitary-adrenal axis. Cessation of inhaled triamcinolone acetonide therapy resulted in resolution of obesity and hirsutism, resumption of normal growth, and a return to normal of serum cortisol levels and urinary 17-hydroxycorticosteroid excretion. Careful monitoring of growth velocity and (if clinically indicated) morning serum cortisol levels in asthmatic children using inhaled corticorsteroids will detect the rare instance of glucocorticoid excess resulting from systemic absorption of these drugs.

scholarly journals Improving glucocorticoid replacement therapy using a novel modified-release hydrocortisone tablet: a pharmacokinetic study

2009 ◽  
Vol 161 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Gudmundur Johannsson ◽  
Ragnhildur Bergthorsdottir ◽  
Anna G Nilsson ◽  
Hans Lennernas ◽  
Thomas Hedner ◽  
...  
Keyword(s):  
Single Dose ◽  
Replacement Therapy ◽  
Plasma Cortisol ◽  
Plasma Concentrations ◽  
Pharmacokinetic Studies ◽  
Double Blind ◽  
Once Daily ◽  
Physiological Serum ◽  
Cortisol Levels ◽  
Dual Release

BackgroundEndogenous plasma cortisol levels have a well-defined circadian rhythm. The aim of this project is to develop a once daily oral dual-release formulation for cortisol replacement therapy that mimics the diurnal variation in the plasma cortisol profile.ObjectiveTo determine single-dose plasma pharmacokinetics and dose-proportionality of oral 5 and 20 mg dual-release hydrocortisone tablets in healthy volunteers. In addition, the effect of food intake was investigated for the 20 mg dose.DesignA randomised, controlled, two-way cross-over, double-blind, phase I study of oral hydrocortisone (modified (dual) release; 5 and 20 mg) with an open food-interaction arm.MethodsThe single dose pharmacokinetic studies were performed with betamethasone suppression. The two first study days were blinded and randomised between morning administration of 5 and 20 mg tablet in a fasting state. The third day was open with a 20 mg tablet taken 30 min after a high-calorie, high-fat meal. The plasma samples were assayed using both a validated LC–MS/MS and an immunoassay. The plasma pharmacokinetic variables were calculated using non-compartmental data analysis.ResultsThe time to reach a clinically significant plasma concentration of cortisol (>200 nmol/l) was within 20 min and a mean peak of 431 (s.d. 126) nmol/l was obtained within 50 min after administration of the 20 mg tablet. Plasma cortisol levels remained above 200 nmol/l for around 6 h thereafter and all plasma concentrations 18–24 h after intake were below 50 nmol/l. In the fed state the time to reach 200 nmol/l was delayed by 28 and 9 min based on LC–MS/MS and immunoassay, respectively. The 5 and 20 mg tablets produced an increase in plasma exposure of cortisol that was not fully dose proportional.ConclusionThe dual release hydrocortisone tablet with once-daily administration produced a diurnal plasma cortisol profile mimicking the physiological serum cortisol profile.

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