scholarly journals Pharmacokinetic profile of injectable tramadol in the koala (Phascolarctos cinereus) and prediction of its analgesic efficacy

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247546
Author(s):  
Benjamin Kimble ◽  
Larry Vogelnest ◽  
Peter Valtchev ◽  
Merran Govendir

Tramadol is used as an analgesic in humans and some animal species. When tramadol is administered to most species it undergoes metabolism to its main metabolites M1 or O-desmethyltramadol, and M2 or N-desmethyltramadol, and many other metabolites. This study describes the pharmacokinetic profile of tramadol when a single subcutaneous bolus of 2 mg/kg was initially administered to two koalas. Based on the results of these two koalas, subsequently 4 mg/kg as a single subcutaneous injection, was administered to an additional four koalas. M1 is recognised as an active metabolite and has greater analgesic activity than tramadol, while M2 is considered inactive. A liquid chromatography assay to quantify tramadol, M1 and M2 in koala plasma was developed and validated. Liquid chromatography-mass spectrometry confirmed that M1 had been identified. Additionally, the metabolite didesmethyltramadol was identified in chromatograms of two of the male koalas. When 4 mg/kg tramadol was administered, the median half-life of tramadol and M1 were 2.89 h and 24.69 h, respectively. The M1 plasma concentration remained well above the minimally effective M1 plasma concentration in humans (approximately 36 ng/mL) over 12 hours. The M1 plasma concentration, when tramadol was administered at 2 mg/kg, did not exceed 36 ng/mL at any time-point. When tramadol was administered at 2 mg/kg and 4 mg/kg the area under the curve M1: tramadol ratios were 0.33 and 0.50, respectively. Tramadol and M1 binding to plasma protein were determined using thawed, frozen koala plasma and the mean binding was 20% and 75%, respectively. It is concluded that when tramadol is administered at 4 mg/kg as a subcutaneous injection to the koala, it is predicted to have some analgesic activity.

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3242
Author(s):  
Nazlı Turan Yücel ◽  
Ümmühan Kandemir ◽  
Ümide Demir Özkay ◽  
Özgür Devrim Can

Vortioxetine is a multimodal antidepressant drug that affects several brain neurochemicals and has the potential to induce various pharmacological effects on the central nervous system. Therefore, we investigated the centrally mediated analgesic efficacy of this drug and the mechanisms underlying this effect. Analgesic activity of vortioxetine (5, 10 and 20 mg/kg, p.o.) was examined by tail-clip, tail-immersion and hot-plate tests. Motor performance of animals was evaluated using Rota-rod device. Time course measurements (30–180 min) showed that vortioxetine (10 and 20 mg/kg) administrations significantly increased the response latency, percent maximum possible effect and area under the curve values in all of the nociceptive tests. These data pointed out the analgesic effect of vortioxetine on central pathways carrying acute thermal and mechanical nociceptive stimuli. Vortioxetine did not alter the motor coordination of mice indicating that the analgesic activity of this drug was specific. In mechanistic studies, pre-treatments with p-chlorophenylalanine (serotonin-synthesis inhibitor), NAN-190 (serotonin 5-HT1A receptor antagonist), α-methyl-para-tyrosine (catecholamine-synthesis inhibitor), phentolamine (non-selective α-adrenoceptor blocker), and naloxone (non-selective opioid receptor blocker) antagonised the vortioxetine-induced analgesia. Obtained findings indicated that vortioxetine-induced analgesia is mediated by 5-HT1A serotonergic, α-adrenergic and opioidergic receptors, and contributions of central serotonergic and catecholaminergic neurotransmissions are critical for this effect.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Cecilia Nwadiuto Amadi ◽  
Wisdom Izuchukwu Nwachukwu

Abstract Background Cola nitida is commonly chewed in many West African cultures to ease hunger pangs and sometimes for their stimulant and euphoriant qualities. Metoclopramide is a known substrate for P-gp, SULT2A1 and CYP2D6 and studies have revealed that caffeine- a major component of Cola nitida can induce P-glycoprotein (P-gp), SULT2A1 and SULT1A1, hence a possible drug interaction may occur on co-administration. The aim of this study was to investigate the pharmacokinetic interactions of Cola nitida and metoclopramide in rabbits. Methods The study was performed in two stages using five healthy male rabbits with a 1-week washout period between treatments. Stage one involved oral administration of metoclopramide (0.5 mg/kg) alone while in the second stage, metoclopramide (0.5 mg/kg) was administered concurrently with Cola nitida (0.7 mg/kg). Blood samples were collected after each stage at predetermined intervals and analyzed for plasma metoclopramide concentration using HPLC. Results Compared with control, the metoclopramide/Cola nitida co-administration produced a decrease in plasma concentration of metoclopramide at all the time intervals except at the 7th hour. The following pharmacokinetic parameters were also decreased: area under the curve (51%), peak plasma concentration (39%), half-life (51%); while an increase in elimination rate constant (113%) and clearance rate (98%) were noted indicating rapid elimination of the drug. A minimal decrease in absorption rate (10%) was also observed. Conclusions The results of this study reveal a possible herb-drug interaction between Cola nitida and metoclopramide.


2016 ◽  
Vol 4 (1) ◽  
pp. 93 ◽  
Author(s):  
Mohamed Aboubakr

The pharmacokinetic profile of cefotaxime following a single intravenous (IV) and intramuscular (IM) injection was studied in Muscovy ducks. Cefotaxime was given at a dose rate of 25 mg/kg b.wt. for both routes. After IV injection, the plasma levels of cefotaxime estimated at 0.08 h was 70.87 μg/ml, which declined gradually and cefotaxime was detected up to 10 h (0.59 μg/ml). The mean values of CL, Vdss and t1/2β of cefotaxime in muscovy ducks were 0.22 l/kg/h, 0.51 l/kg and 1.81 h, respectively. After IM injection, maximum plasma concentration (Cmax) was (14.72 μg/ml), time of maximal plasma concentration (tmax) was (2.3 h) and elimination half-life (t1/2el)was (1.77 h). Bioavailability following IM injection was 79.61%, and in vitro protein binding percent was 31.48%. A recommended IM dosage for cefotaxime in muscovy ducks would be 30 mg/kg b.wt., repeated at 12 h intervals will provide a therapeutic plasma concentrations exceeding the MIC≤0.5 µg/ml for most susceptible pathogens in ducks.


1988 ◽  
Vol 16 (1) ◽  
pp. 44-49 ◽  
Author(s):  
E. Källström ◽  
M. Heikinheimo ◽  
H. Quiding

The pharmacokinetic variables of ibuprofen 600 mg were investigated after administration of Brufen and compared to administration of Burana and Ibumetin. The investigation was carried out as a randomized single-dose crossover study in 17 healthy volunteers. The mean maximum plasma concentrations of ibuprofen were 58, 45 and 54 μg/ml after administration of Brufen, Burana and Ibumetin, respectively, the time to reach this being 1.4, 2.1 and 1.6 h, respectively, after administration. The differences between Brufen and Burana were significant. The relative bioavailability was very similar between Brufen and Burana but about 8% lower for Ibumetin and this difference between Brufen and Ibumetin was significant. Thus, different brands of ibuprofen may not be pharmacokinetically interchangeable and the results show that Brufen is superior to either Burana or Ibumetin when considering both the rate and extent of absorption. These findings are clinically interesting since a high and early plasma concentration of ibuprofen seems to be related to increased analgesic efficacy.


2018 ◽  
Vol 64 (4) ◽  
pp. 161-168
Author(s):  
Diana Pop ◽  
Ana-Maria Gheldiu ◽  
Monica Oroian ◽  
Adriana Marcovici ◽  
Sandeep Bhardwaj ◽  
...  

AbstractObjective: To evaluate the food effect on glicazide disposition in clinical trials conducted on healthy Caucasian volunteers who were given a new modified release oral formulation of Gliclazide 60 mg developed by Sun Pharmaceutical Industries, India.Methods: The studies were designed as open-label, randomized, single-dose, crossover studies that consisted of two periods. During each study, venous blood samples were taken before and after drug administration up to 96 hours. Subsequently, individual plasma profiles were determined and non-compartmental method was employed for the assessment of food effect on the pharmacokinetic profile of gliclazide. The statistical significance of differences for the main pharmacokinetic parameters was evaluated by ANOVA test, for p < 0.05 statistical significance was decided. The relative profiles of absorption of gliclazide were obtained by mathematical deconvolution. All calculation were performed by Phoenix WinNonlin®.Results: High-fat, high-calorie meal decreased gliclazide exposure. The mean maximum plasma concentration decreased with 14%, while the mean total area under the plasma concentration-time profile registered a 17% decrease. The elimination half-lives under fasted and fed conditions were comparable and the time to maximum plasma concentration was shortened under fed condition. Safety evaluation showed that overall gliclazide was well tolerated under both fasted and fed condition.Conclusions: The statistical analysis revealed the lack of food effect on the new modified release tablets of Gliclazide 60 mg. However, before stating a definite conclusion regarding the food effect on gliclazide pharmacokinetic profile, additional studies on patients with type 2 diabetes mellitus should be conducted.


Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3550
Author(s):  
Fumie Tokonami ◽  
Benjamin Kimble ◽  
Merran Govendir

Fentanyl was administered as a single intravenous bolus injection at 5 µg/kg to five koalas and fentanyl plasma concentrations for a minimum of 2 h were quantified by an enzyme-linked immunosorbent assay (ELISA). The median (range) fentanyl elimination half-life and clearance were 0.53 (0.38–0.91) h, and 10.01 (7.03–11.69) L/kg/h, respectively. Assuming an analgesic therapeutic plasma concentration of 0.23 ng/mL (extrapolated from human studies), an intravenous constant infusion rate was estimated at approximately between 1.7 to 2.7 µg/kg/h (using the clearance 95% confidence intervals). A transdermal fentanyl patch was applied to the antebrachium of an additional two koalas for 72 h. Fentanyl plasma concentrations were determined during the patch application and after patch removal at 80 h. The fentanyl plasma concentration was greater than 0.23 ng/mL after 12 to 16 h. While the patch was applied, the maximum fentanyl concentration was approximately 0.7 ng/mL from 32 to 72 h. Fentanyl plasma concentrations increased to 0.89 ng/mL 1 h after the patch was removed, and then decreased to a mean of 0.47 ng/mL at 80 h. The transdermal fentanyl patch is likely to provide some level of analgesia but should be initially co-administered with another faster acting analgesic for the first 12 h.


Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.


2020 ◽  
Vol 16 ◽  
Author(s):  
Xi He ◽  
Wenjun Hu ◽  
Fanhua Meng ◽  
Xingzhou Li

Background: The broad-spectrum antiparasitic drug nitazoxanide (N) has been repositioned as a broad-spectrum antiviral drug. Nitazoxanide’s in vivo antiviral activities are mainly attributed to its metabolitetizoxanide, the deacetylation product of nitazoxanide. In reference to the pharmacokinetic profile of nitazoxanide, we proposed the hypotheses that the low plasma concentrations and the low system exposure of tizoxanide after dosing with nitazoxanide result from significant first pass effects in the liver. It was thought that this may be due to the unstable acyloxy bond of nitazoxanide. Objective: Tizoxanide prodrugs, with the more stable formamyl substituent attached to the hydroxyl group rather than the acetyl group of nitazoxanide, were designed with the thought that they might be more stable in plasma. It was anticipated that these prodrugs might be less affected by the first pass effect, which would improve plasma concentrations and system exposure of tizoxanide. Method: These O-carbamoyl tizoxanide prodrugs were synthesized and evaluated in a mouse model for pharmacokinetic (PK) properties and in an in vitro model for plasma stabilities. Results: The results indicated that the plasma concentration and the systemic exposure of tizoxanide (T) after oral administration of O-carbamoyl tizoxanide prodrugs were much greater than that produced by equimolar dosage of nitazoxanide. It was also found that the plasma concentration and the systemic exposure of tizoxanide glucuronide (TG) were much lower than that produced by nitazoxanide. Conclusion: Further analysis showed that the suitable plasma stability of O-carbamoyl tizoxanide prodrugs is the key factor in maximizing the plasma concentration and the systemic exposure of the active ingredient tizoxanide.


2021 ◽  
Vol 14 (2) ◽  
pp. 162
Author(s):  
Félicien Le Louedec ◽  
Fanny Gallais ◽  
Fabienne Thomas ◽  
Mélanie White-Koning ◽  
Ben Allal ◽  
...  

Therapeutic drug monitoring of ibrutinib is based on the area under the curve of concentration vs. time (AUCIBRU) instead of trough concentration (Cmin,ss) because of a limited accumulation in plasma. Our objective was to identify a limited sampling strategy (LSS) to estimate AUCIBRU associated with Bayesian estimation. The actual AUCIBRU of 85 patients was determined by the Bayesian analysis of the full pharmacokinetic profile of ibrutinib concentrations (pre-dose T0 and 0.5, 1, 2, 4 and 6 h post-dose) and experimental AUCIBRU were derived considering combinations of one to four sampling times. The T0–1–2–4 design was the most accurate LSS (root-mean-square error RMSE = 11.0%), and three-point strategies removing the 1 h or 2 h points (RMSE = 22.7% and 14.5%, respectively) also showed good accuracy. The correlation between the actual AUCIBRU and Cmin,ss was poor (r2 = 0.25). The joint analysis of dihydrodiol-ibrutinib metabolite concentrations did not improve the predictive performance of AUCIBRU. These results were confirmed in a prospective validation cohort (n = 27 patients). At least three samples, within the pre-dose and 4 h post-dose period, are necessary to estimate ibrutinib exposure accurately.


2020 ◽  
Vol 4 (04) ◽  
pp. 187-192
Author(s):  
Jared A. Warren ◽  
Oliver Scotting ◽  
Hiba K. Anis ◽  
James Bircher ◽  
Alison K. Klika ◽  
...  

AbstractDiagnostic thresholds used to standardize the definition for prosthetic joint infection (PJI) have largely focused on total joint arthroplasty (TJA). Established PJI thresholds exist for serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in TJA; however, they do not exist for revision hip hemiarthroplasty (rHHA). The purpose of this study was to establish thresholds for (1) ESR and (2) CRP to diagnose PJI in rHHA. Data were collected on a prospective cohort of 69 rHHA patients undergoing orthopaedic surgery between 1/2017 and 2/2019 in a single health care system. Procedures were categorized as septic or aseptic revisions using Musculoskeletal Infection Society (MSIS) criteria (2013). There were 44 ESRs (n = 28 aseptic, n = 16 septic) and 46 CRPs (n = 29 aseptic, n = 17 septic) available for analysis. Two tailed t-tests were performed to compare the mean ESR and CRP in aseptic and septic cases. Receiver operator characteristic (ROC) curves were generated to obtain diagnostic cutoff thresholds using the Youden's Index (J) for ESR and CRP. The mean ESR was 50.3 ± 30.6 mm/h versus 15.4 ± 17.7 mm/h (p < 0.001), while the mean CRP was 29.9 ± 24.8 mg/L versus 4.1 ± 8.2 mg/L (p < 0.001) for septic and aseptic revisions, respectively. The diagnostic threshold for PJI determined by the ROC curve was 44 mm/h for ESR (sensitivity = 56.3%; specificity = 100.0%; J = 0.563; area under the curve (AUC) = 0.845), while it was 12.5 mg/L for CRP (sensitivity = 70.6%; specificity = 96.6%; J = 0.672; AUC = 0.896). For patients with HHA, an ESR of 44 mm/h was and a CRP of 12.5 mg/L was highly specific for PJI. The thresholds are similar to the MSIS thresholds currently published. Larger prospective trials are needed to establish more robust and conclusive diagnostic criteria for PJI in HHA, including investigations not only of ESR and CRP but synovial white blood cell count and synovial polymorphonuclear leukocytes % as well.


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