Trigeminal Neuralgia: Time Course of Pain in Relation to Carbamazepine Dosing

Cephalalgia ◽  
1981 ◽  
Vol 1 (2) ◽  
pp. 91-97 ◽  
Author(s):  
Torbjörn Tomson ◽  
Karl Ekbom
Keyword(s):  
Plasma Concentration ◽  
Trigeminal Neuralgia ◽  
Time Course ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Significant Drop ◽  
Idiopathic Trigeminal Neuralgia ◽  
Full Effect ◽  
Pain Distribution

Eight in-patients with idiopathic trigeminal neuralgia (TN) were studied while receiving carbamazepine (CBZ) treatment. The aim was to study diurnal pain distribution, its relation to CBZ dosing and plasma concentration and the effect of decreasing the dose. All pain attacks were registered by the patients at three-hour intervals. CBZ was given b.i.d. in a single blind manner with the patient unaware of dose and dose changes. Plasma concentrations of CBZ were followed every fourth hour during a period of altogether sixteen dosage intervals. The diurnal pain distribution revealed marked intra-individual similarities with pain-free nights and a significant drop in pain during mid-day hours. The latter coincided in time with the peak plasma concentration of CBZ, thus indicating an effect of plasma concentration fluctuations on pain relief. Shorter dosage intervals might therefore be beneficial in problem cases. A significant increase in pain was detected within six to nine hours after a dose reduction, whereas the full effect of the dose change seemed to be established only after one day.

scholarly journals Pharmacokinetic Profile of Oral Administration of Mefloquine to Clinically Normal Cats: A Preliminary In-Vivo Study of a Potential Treatment for Feline Infectious Peritonitis (FIP)

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1000
Author(s):  
Jane Yu ◽  
Benjamin Kimble ◽  
Jacqueline M. Norris ◽  
Merran Govendir
Keyword(s):  
Plasma Concentration ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Feline Calicivirus ◽  
Potential Treatment ◽  
Feline Infectious Peritonitis ◽  
Feline Coronavirus

The pharmacokinetic profile of mefloquine was investigated as a preliminary study towards a potential treatment for feline coronavirus infections (such as feline infectious peritonitis) or feline calicivirus infections. Mefloquine was administered at 62.5 mg orally to seven clinically healthy cats twice weekly for four doses and mefloquine plasma concentrations over 336 h were measured using high pressure liquid chromatography (HPLC). The peak plasma concentration (Cmax) after a single oral dose of mefloquine was 2.71 ug/mL and time to reach Cmax (Tmax) was 15 h. The elimination half-life was 224 h. The plasma concentration reached a higher level at 4.06 ug/mL when mefloquine was administered with food. Adverse effects of dosing included vomiting following administration without food in some cats. Mild increases in serum symmetric dimethylarginine (SDMA), but not creatinine, concentrations were observed. Mefloquine may provide a safe effective treatment for feline coronavirus and feline calicivirus infections in cats.

Inhibitory Effect of Citalopram on the Pharmacokinetics of Carvedilol in Rats and in vitro Models

Pharmacology ◽  
2017 ◽  
Vol 100 (5-6) ◽  
pp. 301-307
Author(s):  
Maria Bianca Abrudan ◽  
Dana Maria Muntean ◽  
Daniela Saveta Popa ◽  
Ana-Maria Gheldiu ◽  
Maria Adriana Neag ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Plasma Concentration ◽  
Metabolic Rate ◽  
Liver Microsome ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Femoral Vein ◽  
Plasma Concentrations ◽  
Drug Drug Interaction

Background/Aims: The aim of this study was to investigate the drug-drug interaction between carvedilol and citalopram based on carvedilol metabolism in vitro and his pharmacokinetics (PKs) in vivo after the oral administration of the single drug and both drugs, and reveal citalopram effects on the PKs of carvedilol. Methods: Each rat was cannulated on the femoral vein, prior to being connected to BASi Culex ABC®. Carvedilol was orally administrated in rats (3.57 mg/kg body weight [b.w.]) in the absence of citalopram or after a pre-treatment with multiple oral doses of citalopram (1.42 mg/kg b.w.). Plasma concentrations of carvedilol were determined using high-performance liquid chromatography-MS at the designated time points after drug administration, and the main PK parameters were calculated by noncompartmental analysis. In addition, effects of citalopram on the metabolic rate of carvedilol were investigated using rat-pooled liver microsome incubation systems. Results: During co-administration, significant increases of the area under the plasma concentration-time curve as well as of the peak plasma concentration were observed. The rat-pooled liver microsome incubation experiment indicated that citalopram could decrease the metabolic rate of carvedilol. Conclusion: Citalopram co-administration led to a significant alteration of carvedilol's PK profile in rats; it also demonstrated, in vitro, these effects could be explained by the existence of a drug-drug interaction mediated by CYP2D6 inhibition.

scholarly journals Influence of Bisphosphonates or Recombinant Human Parathyroid Hormone on in Vitro Chemotherapy Sensitivity in Acute Lymphoblastic Leukemia Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4355-4355
Author(s):  
Demi T.C. de Winter ◽  
Jenneke E. van Atteveld ◽  
Jessica G.C.A.M. Buijs-Gladdines ◽  
Rob Pieters ◽  
Sebastian J.C.M.M. Neggers ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Peak Plasma ◽  
Lymphoblastic Leukemia ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Leukemia Cell ◽  
Chemotherapeutic Agents ◽  
Mineral Density ◽  
All Treatment

Abstract BACKGROUND Osteonecrosis and low bone mineral density (BMD) are serious osteogenic side effects of acute lymphoblastic leukemia (ALL) treatment. Bisphosphonates and recombinant human parathyroid hormone (rPTH) tend to be used to ameliorate osteonecrosis-related symptoms as well as to enhance bone mineral density in children with ALL and severe bone fragility. Only one preclinical study on the safety of bisphosphonates during ALL treatment is available, which raises concerns about their impact on leukemic drug sensitivity. Here, we assessed the influence of various bone-modifying agents (zoledronate, pamidronate and rPTH) on in vitro cytotoxicity of chemotherapeutic agents (vincristine (VCR), daunorubicin (DNR), dexamethasone (DEXA), 6-mercaptopurine (6-MP), PEG-asparaginase (PEG-ASP)) and prednisone (PRED) that are commonly used in ALL treatment. METHODS Potential cytotoxic effects of the bone-modifying agents on leukemia cell viability and on in vitro cytotoxic responses of chemotherapeutic agents were tested in various T-cell and B-cell leukemia cell lines using methyl-thiazol-tetrazolium (MTT) assays. Bone-modifying agents were added at concentrations up to a five-fold of their physiological peak plasma concentration. For each assay, 50th percentile of maximal inhibitory concentration was determined. To quantify the combined effects of the bone-modifying agents on chemotherapeutic agent-induced cytotoxicity, median (interquartile range) combination indexes (CI) were calculated. We considered a median CI of < 0.8 as synergism and > 1.2 as antagonism (based on the method of Chou). RESULTS Zoledronate, pamidronate or rPTH in combination with DNR, 6-MP and PEG-ASP showed median CI values between 0.8 and 1.2. Variable inconclusive results were obtained in combination with VCR. Only the combination of a five-fold peak plasma concentration of zoledronate or pamidronate with DEXA resulted in median CI values of 1.15 (range, 1.08-1.48), and 1.34 (range, 1.07-1.62), respectively. Additional experiments using DEXA as well as PRED in combination with one-, three- or five-fold physiological peak plasma concentrations of zoledronate or pamidronate revealed that median CI values stay within 0.8 and 1.2, except for DEXA exposed leukemia cells in combination with a five-fold physiological peak plasma concentration of pamidronate which repeatedly showed a median CI value above 1.2 (1.34, range 1.04-1.86). CONCLUSIONS Zoledronate, pamidronate or rPTH do not seem to influence drug sensitivity of DNR, 6-MP or PEG-ASP, even at a five-fold physiological peak plasma concentration. Nevertheless, our findings suggest a minimal effect of pamidronate on DEXA-induced leukemia cell death. This suggests that even though zoledronate or pamidronate do not seem to negatively influence DEXA- or PRED- induced toxicity in expected physiological concentrations (one- to three-fold physiological peak plasma concentrations), these bone-modifying agents may only be considered with caution in individual cases, and preferably in clinical trial settings before being applied on a large scale in children with ALL. Disclosures No relevant conflicts of interest to declare.

Comparative Bioequivalence and Efficacy of Two Sustained-Release Procainamide Formulations in Patients with Cardiac Arrhythmias

1988 ◽  
Vol 22 (7-8) ◽  
pp. 554-558 ◽  
Author(s):  
Daniel E. Hilleman ◽  
Albert J. Patterson ◽  
Syed M. Mohiuddin ◽  
Brian G. Ortmeier ◽  
Christopher J. Destache
Keyword(s):  
Plasma Concentration ◽  
Sustained Release ◽  
Cardiac Arrhythmias ◽  
Peak Plasma ◽  
Statistical Significance ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Blood Sampling ◽  
Time Curve ◽  
Alternate Test

This investigation evaluated the bioequivalence and efficacy of two sustained-release procainamide products. Ten patients with cardiac arrhythmias were randomized to product A (Procan-SR) or product B (Pronestyl-SR). After nine doses of study medication, plasma procainamide and N-acetylprocainamide concentrations were obtained to determine the area under the concentration versus time curve at steady state (AUCss), mean plasma concentration (Cavss), the observed peak plasma concentration (Cmaxss), the observed trough plasma concentration (Cminss), and the apparent time to achieve Cmaxss (tmax). The products were compared on a milligram-equivalent (adjusted) basis. Following completion of blood sampling, patients were crossed-over to the alternate product. There was no washout between treatments. After nine doses of the alternate test medications, blood sampling was repeated. Differences in AUCss, Cavss, Cmaxss, tmax, and intradose peak/trough ratios were not statistically significant. Within-group variability in AUCss, Cavss Cmaxss, and tmax was greater with product B, but this trend did not reach statistical significance. Antiarrhythmic efficacy was not significantly different between the two treatments. Although the greater bioequivalence, lesser variability, and the greater number of tablet dosage sizes would favor product A, patients stabilized on a particular brand of sustained-release procainamide should not be switched to another product without careful monitoring. One patient in this study developed nonsustained ventricular tachycardia with low procainamide plasma concentrations after being switched from product A to product B.

scholarly journals Pharmacokinetics of Lornoxicam in rabbits after single intravenous bolus and intramuscular administrations

2016 ◽  
Vol 4 (1) ◽  
pp. 66
Author(s):  
Abubakr El-Mahmoudy
Keyword(s):  
Plasma Concentration ◽  
Half Life ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Volume Of Distribution ◽  
Bolus Administration ◽  
Systemic Bioavailability ◽  
Total Body

The pharmacokinetics of lornoxicam (a non-steroidal anti-inflammatory drug) at a dose of 0.4 mg/Kg body weight was evaluated after single intravenous (i.v.) and intramuscular (i.m.) bolus administrations in rabbits. An HPLC assay using pure lornoxicam base as a standard was used to measure its concentrations in plasma at prefixed time points up to 12 hours post administration. Following an i.v. bolus injection, the plasma concentration-time curves of lornoxicam were best represented by two-compartment open model. The drug was rapidly distributed and moderately eliminated with half-lives of distribution (t1/2α) and elimination (t1/2β) of 0.238 and 2.611 h, respectively. The volume of distribution was large with (Vdss) value of 1.499 L. The total body clearance (ClB) was 0.413 L/h. After i.m. bolus administration of the same dose, lornoxicam was moderately and completely absorbed in rabbits with an absorption half-life (t½ab) of 1.228 h with peak plasma concentration (Cmax) of 0.463 μg/mL attained at 1.512 h (Tmax) and systemic bioavailability of 99.79%. The elimination half-life following i.m. administration was 2.283 h. The extent of plasma protein binding percent was 98.9%. The study recommends the use of lornoxicam in rabbits because of its good pharmacokinetic profile indicated by good absorption, bioavailability and plasma concentrations.

scholarly journals Effects of the Antifungals Voriconazole and Fluconazole on the Pharmacokinetics of S-(+)- and R-(−)-Ibuprofen

2006 ◽  
Vol 50 (6) ◽  
pp. 1967-1972 ◽  
Author(s):  
Ville-Veikko Hynninen ◽  
Klaus T. Olkkola ◽  
Kari Leino ◽  
Stefan Lundgren ◽  
Pertti J. Neuvonen ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Geometric Mean ◽  
Plasma Concentrations ◽  
Time Curve ◽  
Respective Control ◽  
Control Value ◽  
Racemic Ibuprofen ◽  
The Mean

ABSTRACT Our objective was to study the effects of the antifungals voriconazole and fluconazole on the pharmacokinetics of S-(+)- and R-(−)-ibuprofen. Twelve healthy male volunteers took a single oral dose of 400 mg racemic ibuprofen in a randomized order either alone, after ingestion of voriconazole at 400 mg twice daily on the first day and 200 mg twice daily on the second day, or after ingestion of fluconazole at 400 mg on the first day and 200 mg on the second day. Ibuprofen was ingested 1 h after administration of the last dose of voriconazole or fluconazole. Plasma concentrations of S-(+)- and R-(−)-ibuprofen were measured for up to 24 h. In the voriconazole phase, the mean area under the plasma concentration-time curve (AUC) of S-(+)-ibuprofen was 205% (P < 0.001) of the respective control value and the mean peak plasma concentration (C max) was 122% (P < 0.01) of the respective control value. The mean elimination half-life (t 1/2) was prolonged from 2.4 to 3.2 h (P < 0.01) by voriconazole. In the fluconazole phase, the mean AUC of S-(+)-ibuprofen was 183% of the control value (P < 0.001) and its mean C max was 116% of the control value (P < 0.05). The mean t 1/2 of S-(+)-ibuprofen was prolonged from 2.4 to 3.1 h (P < 0.05) by fluconazole. The geometric mean S-(+)-ibuprofen AUC ratios in the voriconazole and fluconazole phases were 2.01 (90% confidence interval [CI], 1.80 to 2.22) and 1.82 (90% CI, 1.72 to 1.91), respectively, i.e., above the bioequivalence acceptance upper limit of 1.25. Voriconazole and fluconazole had only weak effects on the pharmacokinetics of R-(−)-ibuprofen. In conclusion, voriconazole and fluconazole increased the levels of exposure to S-(+)-ibuprofen 2- and 1.8-fold, respectively. This was likely caused by inhibition of the cytochrome P450 2C9-mediated metabolism of S-(+)-ibuprofen. A reduction of the ibuprofen dosage should be considered when ibuprofen is coadministered with voriconazole or fluconazole, especially when the initial ibuprofen dose is high.

The Pharmacokinetics of Milrinone in Pediatric Patients after Cardiac Surgery 

1999 ◽  
Vol 90 (4) ◽  
pp. 1012-1018 ◽  
Author(s):  
James M. Bailey ◽  
Bruce E. Miller ◽  
Wei Lu ◽  
Steven R. Tosone ◽  
Kirk R. Kanter ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Plasma Concentration ◽  
Cardiac Index ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Compartment Model ◽  
Pharmacokinetic Analysis ◽  
Population Pharmacokinetic ◽  
Loading Dose

Background Milrinone has been shown to increase cardiac output in children after cardiac surgery, but pharmacokinetic analysis has not been used to identify effective dose regimens. The purpose of this study was to characterize the pharmacokinetics of milrinone in infants and children and to apply the results to the issue of dosing. Methods Twenty children were studied after they underwent repair of congenital cardiac defects. Control hemodynamic measurement was made after the children were separated from cardiopulmonary bypass, and each patient was given a loading dose of 50 microg/kg progressively in 5 min. Hemodynamic measurements were recorded again at the end of the loading dose and when a blood sample was taken to determine milrinone plasma concentrations. Further blood samples were taken during the next 16 h for milrinone plasma concentration analysis. The pharmacokinetics of milrinone were analyzed using the population pharmacokinetic program NONMEM. Results The loading dose of milrinone resulted in a mean decrease in mean blood pressure of 12% and a mean increase in cardiac index of 18% at a mean peak plasma concentration of 235 ng/ml. The pharmacokinetics of milrinone were best described by a three-compartment model. In the optimal model, all volumes and distribution clearances were proportional to weight, and weight-normalized elimination clearance was proportional to age; ie., Cl1 = 2.5 x weight x (1 + 0.058 x age) where Cl1 is expressed as ml/min, and the units of weight and age are kg and months, respectively. Conclusions A loading dose of 50 microg/kg effectively increases cardiac index in children after cardiac surgery. Simulations indicate that the peak plasma concentration can be maintained by following the loading dose of 50 microg/kg with an infusion of approximately 3 microg x kg(-1) x min(-1) for 30 min and then a maintenance infusion, which may require adjustment for age.

scholarly journals Pharmacokinetics of clarithromycin after single intravenous and intracrop bolus administrations to broiler chickens

2016 ◽  
Vol 4 (1) ◽  
pp. 12 ◽  
Author(s):  
Hanady AwadAllah ◽  
Shaban Awidat ◽  
Abubakr El-Mahmoudy
Keyword(s):  
Plasma Concentration ◽  
Half Life ◽  
Broiler Chickens ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Pharmacokinetic Profile ◽  
Volume Of Distribution ◽  
Bolus Administration ◽  
Systemic Bioavailability

<p>The pharmacokinetics of clarithromycin at a dose of 7.5 mg/kg body weight was evaluated after single intravenous (i.v.) and intracrop (i.c.) bolus administrations in broilers. An HPLC assay using pure clarithromycin base as a standard was used to measure its concentrations in plasma. Following an i.v. bolus injection, the plasma concentration-time curves of clarithromycin were best represented by two-compartment open models. The drug was rapidly distributed and moderately eliminated with half-lives of distribution (<em>t</em><sub>1/2α</sub>) and elimination (<em>t</em><sub>1/2β</sub>) of 0.38 and 4.58 h, respectively. The volume of distribution was large with (V<sub>dss</sub>) value of 6.89 L. The total body clearance (<em>Cl</em><sub>B</sub>) was 1.2 L/h. After i.c. bolus administration of the same dose, clarithromycin was moderately absorbed in broilers with an intermediate absorption half-life (<em>T</em><sub>½ab</sub>) of 0.72 h with peak plasma concentration (<em>C</em><sub>max</sub>) of 1.69 μg/ml attained at 1.7 h (<em>T</em><sub>max</sub>) and systemic bioavailability of 66.54%. The elimination half-life following i.c. administration was 2.11 h. The extent of plasma protein binding percent was 52%. The study recommends the use of clarithromycin in broilers because of its good pharmacokinetic profile indicated by good absorption, bioavailability and plasma concentrations ≥ MICs of many sensitive microorganisms.</p>

Plasma Bupivacaine Concentrations after Axillary Block in Children

1986 ◽  
Vol 14 (4) ◽  
pp. 343-346 ◽  
Author(s):  
R. J. Campbell ◽  
K. F. Ilett ◽  
L. Dusci
Keyword(s):  
Plasma Concentration ◽  
Brachial Plexus Block ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Plasma Concentrations ◽  
Axillary Block ◽  
Time To Peak ◽  
Plexus Block ◽  
Mean Time ◽  
Venous Plasma

Venous plasma concentrations of bupivacaine were measured in children following axillary brachial plexus block with either 2mg/kg (n = 21) or 3mg/kg (n = 20) of bupivacaine. Absorption was very rapid with a mean time to peak concentrations of 0.37 hours for both doses. Mean peak plasma concentration was 1.35mg/l after the 2mg/kg dose and 1.84mg/kg after the 3mg/kg dose. Even after a 30% allowance for anticipated higher arterial concentrations, the plasma levels found in the present study were well below those at which toxicity is considered likely (>4 mg/l).

A Single Ascending Dose Study of Epigallocatechin Gallate in Healthy Volunteers

2003 ◽  
Vol 31 (2) ◽  
pp. 88-101 ◽  
Author(s):  
U Ullmann ◽  
J Haller ◽  
JP Decourt ◽  
N Girault ◽  
J Girault ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Time Course ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Epigallocatechin Gallate ◽  
Controlled Study ◽  
Maximum Plasma ◽  
Double Blind ◽  
The Mean ◽  
Oral Doses

This randomized, double-blind, placebo-controlled study assessed the safety, tolerability and plasma kinetic behaviour of single oral doses of 94% pure crystalline bulk epigallocatechin gallate (EGCG) under fasting conditions in 60 healthy male volunteers. In each group of 10 subjects, eight received oral EGCG in single doses of 50 mg, 100 mg, 200 mg, 400 mg, 800 mg or 1600 mg, and two received placebo. Blood samples were taken at intervals until 26 h later. The area under the concentration-time curve from 0 h to infinity (AUC(0–∞)), the maximum plasma concentration ( Cmax) of EGCG, the time taken to reach the maximum concentration ( Tmax), and the terminal elimination half-life ( t1/2z) of EGCG were determined. Safety and tolerability were assessed. In each dosage group, the kinetic profile revealed rapid absorption with a one-peak plasma concentration versus time course, followed by a multiphasic decrease consisting of a distribution phase and an elimination phase. The mean AUC(0– ∞) of total EGCG varied between 442 and 10368 ng·h/ml. The according mean Cmax values ranged from 130 to 3392 ng/ml and were observed after 1.3–2.2 h. The mean t1/2z values were seen between 1.9 and 4.6 h. Single oral doses of EGCG up to 1600 mg were safe and very well tolerated.

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