scholarly journals Differential Impact of Nevirapine on Artemether-Lumefantrine Pharmacokinetics in Individuals Stratified by CYP2B6 c.516G>T Genotypes

2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Sa’ad T. Abdullahi ◽  
Julius O. Soyinka ◽  
Adeniyi Olagunju ◽  
Rahman A. Bolarinwa ◽  
Olusola J. Olarewaju ◽  
...  

ABSTRACT There is an increased recognition of the need to identify and quantify the impact of genetic polymorphisms on drug-drug interactions. This study investigated the pharmacogenetics of the pharmacokinetic drug-drug interaction between nevirapine and artemether-lumefantrine in HIV-positive and HIV-negative adult Nigerian subjects. Thirty each of HIV-infected patients on nevirapine-based antiretroviral therapy and HIV-negative volunteers without clinical malaria, but with predetermined CYP2B6 c.516GG and TT genotypes, were administered a complete treatment dose of 3 days of artemether-lumefantrine. Rich pharmacokinetic sampling prior to and following the last dose was conducted, and the plasma concentrations of artemether/dihydroartemisinin and lumefantrine/desbutyl-lumefantrine were quantified using tandem mass spectrometry. Pharmacokinetic parameters of artemether-lumefantrine and its metabolites in HIV-infected patients on nevirapine were compared to those in the absence of nevirapine in HIV-negative volunteers. Overall, nevirapine reduced exposure to artemether and desbutyl-lumefantrine by 39 and 34%, respectively. These reductions were significantly greater in GG versus TT subjects for artemether (ratio of geometric mean [90% confidence interval]: 0.42 [0.29 to 0.61] versus 0.81 [0.51 to 1.28]) and for desbutyl-lumefantrine (0.56 [0.43 to 0.74] versus 0.75 [0.56 to 1.00]). On the contrary, it increased exposure to dihydroartemisinin and lumefantrine by 47 and 30%, respectively. These increases were significantly higher in TT versus GG subjects for dihydroartemisinin (1.67 [1.20 to 2.34] versus 1.25 [0.88 to 1.78]) and for lumefantrine (1.51 [1.20 to 1.90] versus 1.08 [0.82 to 1.42]). This study underscores the importance of incorporating pharmacogenetics into all drug-drug interaction studies with potential for genetic polymorphisms to influence drug disposition.

2019 ◽  
Vol 9 (4) ◽  
pp. 45 ◽  
Author(s):  
Marija Bosilkovska ◽  
Gaelle Magliocco ◽  
Jules Desmeules ◽  
Caroline Samer ◽  
Youssef Daali

Drug metabolic enzymes and transporters are responsible for an important variability in drug disposition. The cocktail approach is a sound strategy for the simultaneous evaluation of several enzyme and transporter activities for a personalized dosage of medications. Recently, we have demonstrated the reliability of the Geneva cocktail, combining the use of dried blood spots (DBS) and reduced dose of phenotyping drugs for the evaluation of the activity of six cytochromes and P-glycoprotein (P-gp). As part of a study evaluating potential drug–drug interactions between probe drugs of the Geneva cocktail, the present paper focuses on the impact of cytochromes (CYP) probe drugs on the disposition of fexofenadine, a P-gp test drug. In a randomized four-way Latin-square crossover study, 30 healthy volunteers (15 men and 15 women) received caffeine 50 mg, bupropion 20 mg, flurbiprofen 10 mg, omeprazole 10 mg, dextromethorphan 10 mg, midazolam 1 mg, and fexofenadine 25 mg alone (or as part of a previously validated combination) and all together (Geneva cocktail). The determination of drug concentrations was performed in DBS samples and pharmacokinetic parameters were calculated. Fexofenadine AUC0–8 h and Cmax decreased by 43% (geometric mean ratio: 0.57; CI 90: 0.50–0.65; p < 0.001) and 49% (geometric mean ratio: 0.51; CI 90: 0.44–0.59; p < 0.001), respectively, when fexofenadine was administered as part of the Geneva cocktail in comparison to fexofenadine alone. Consequently, the apparent oral clearance (Cl/F) increased 1.7-fold (CI 90: 1.49–1.93; p < 0.001). There was no interaction between the remaining probes. In conclusion, an unexpected interaction occurred between fexofenadine and one or several of the following substances: caffeine, bupropion, flurbiprofen, omeprazole, dextromethorphan, and midazolam. Further studies are necessary to elucidate the mechanism of this interaction.


2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Y. S. Chhonker ◽  
V. V. Bhosale ◽  
S. K. Sonkar ◽  
H. Chandasana ◽  
D. Kumar ◽  
...  

ABSTRACT Antimalarial drug combination therapy is now being widely used for the treatment of uncomplicated malaria. The objective of the present study was to investigate the effects of coadministration of intramuscular α/β-arteether (α/β-AE) and oral sulfadoxine-pyrimethamine (SP) on the pharmacokinetic properties of each drug as a drug-drug interaction study to support the development of a fixed-dose combination therapy. A single-dose, open-label, crossover clinical trial was conducted in healthy adult Indian male volunteers (18 to 45 years, n = 13) who received a single dose of AE or SP or a combination dose of AE and SP. Blood samples were collected up to 21 days postadministration, and concentrations of α-AE, β-AE, sulfadoxine, and pyrimethamine were determined by using a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated and statistically analyzed to calculate the geometric mean ratio and confidence interval. Following single-dose coadministration of intramuscular AE and oral SP, the pharmacokinetic properties of α/β-AE were not significantly affected, and α/β-AE had no significant effect on the pharmacokinetic properties of SP in these selected groups of healthy volunteers. However, more investigations are needed to explore this further. (This study has been registered in the clinical trial registry of India under approval no. CTRI/2011/11/002155.)


2016 ◽  
Vol 60 (4) ◽  
pp. 2171-2179 ◽  
Author(s):  
A. Bekker ◽  
H. S. Schaaf ◽  
H. R. Draper ◽  
L. van der Laan ◽  
S. Murray ◽  
...  

ABSTRACTThere are limited pharmacokinetic data for use of the first-line antituberculosis drugs during infancy (<12 months of age), when drug disposition may differ. Intensive pharmacokinetic sampling was performed in infants routinely receiving antituberculosis treatment, including rifampin, isoniazid, pyrazinamide, and ethambutol, using World Health Organization-recommended doses. Regulatory-approved single-drug formulations, including two rifampin suspensions, were used on the sampling day. Assays were conducted using liquid chromatography-mass spectrometry; pharmacokinetic parameters were generated using noncompartmental analysis. Thirty-nine infants were studied; 14 (36%) had culture-confirmed tuberculosis. Fifteen (38%) were premature (<37 weeks gestation); 5 (13%) were HIV infected. The mean corrected age and weight were 6.6 months and 6.45 kg, respectively. The mean maximum plasma concentrations (Cmax) for rifampin, isoniazid, pyrazinamide, and ethambutol were 2.9, 7.9, 41.9, and 1.3 μg/ml, respectively (current recommended adult target concentrations: 8 to 24, 3 to 6, 20 to 50, and 2 to 6 μg/ml, respectively), and the mean areas under the concentration-time curves from 0 to 8 h (AUC0–8) were 12.1, 24.7, 239.4, and 5.1 μg · h/ml, respectively. After adjusting for age and weight, rifampin exposures for the two formulations used differed inCmax(geometric mean ratio [GMR],2.55; 95% confidence interval [CI], 1.47 to 4.41;P= 0.001) and AUC0–8(GMR, 2.52; 95% CI, 1.34 to 4.73;P= 0.005). HIV status was associated with lower pyrazinamideCmax(GMR, 0.85; 95% CI, 0.75 to 0.96;P= 0.013) and AUC0–8(GMR, 0.79; 95% CI, 0.69 to 0.90;P< 0.001) values. No other important differences were observed due to age, weight, prematurity, ethnicity, or gender. In summary, isoniazid and pyrazinamide concentrations in infants compared well with proposed adult target concentrations; ethambutol concentrations were lower but similar to previously reported pediatric studies. The low rifampin exposures require further investigation. (This study has been registered at ClinicalTrials.gov under registration no. NCT01637558.)


Author(s):  
Mingxiang Liao ◽  
Krzysztof G. Jeziorski ◽  
Monika Tomaszewska-Kiecana ◽  
István Láng ◽  
Marek Jasiówka ◽  
...  

Abstract Purpose This study aimed at evaluating the effect of rucaparib on the pharmacokinetics of rosuvastatin and oral contraceptives in patients with advanced solid tumors and the safety of rucaparib with and without coadministration of rosuvastatin or oral contraceptives. Methods Patients received single doses of oral rosuvastatin 20 mg (Arm A) or oral contraceptives ethinylestradiol 30 µg + levonorgestrel 150 µg (Arm B) on days 1 and 19 and continuous doses of rucaparib 600 mg BID from day 5 to 23. Serial blood samples were collected with and without rucaparib for pharmacokinetic analysis. Results Thirty-six patients (n = 18 each arm) were enrolled and received at least 1 dose of study drug. In the drug–drug interaction analysis (n = 15 each arm), the geometric mean ratio (GMR) of maximum concentration (Cmax) with and without rucaparib was 1.29 for rosuvastatin, 1.09 for ethinylestradiol, and 1.19 for levonorgestrel. GMR of area under the concentration–time curve from time zero to last quantifiable measurement (AUC0–last) was 1.34 for rosuvastatin, 1.43 for ethinylestradiol, and 1.56 for levonorgestrel. There was no increase in frequency of treatment-emergent adverse events (TEAEs) when rucaparib was given with either of the probe drugs. In both arms, most TEAEs were mild in severity and considered unrelated to study treatment. Conclusion Rucaparib 600 mg BID weakly increased the plasma exposure to rosuvastatin or oral contraceptives. Rucaparib safety profile when coadministered with rosuvastatin or oral contraceptives was consistent with that of rucaparib monotherapy. Dose adjustments of rosuvastatin and oral contraceptives are not necessary when coadministered with rucaparib. ClinicalTrials.gov NCT03954366; Date of registration May 17, 2019.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Hsiu-Ling Hsiao ◽  
Michael Greeley ◽  
Parasar Pal ◽  
Thomas Langenickel ◽  
Gangadhar Sunkara ◽  
...  

Objective: LCZ696 is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) being developed for the treatment of cardiovascular diseases, including hypertension and heart failure. Ingestion of LCZ696 results in systemic exposure to AHU377 (inactive prodrug of LBQ657, a neprilysin inhibitor) and valsartan (angiotensin receptor blocker). Hydrochlorothiazide (HCTZ) is indicated as first line treatment of hypertension. Since LCZ696 and HCTZ may be co-administered for optimal blood pressure control, this study was conducted to evaluate the pharmacokinetic (PK) drug-drug interaction potential between LCZ696 and HCTZ. Methods: An open-label, three-period, single sequence study in 27 healthy subjects was conducted. In Period 1, subjects received oral HCTZ 25 mg qd x 4 days and were discharged for a 4-10 day washout. In Period 2, subjects received LCZ696 400 mg qd x 5 days, and in Period 3, HCTZ 25 mg qd + LCZ696 400 mg qd x 4 days. Serial PK samples were collected and analyzed by a validated LC-MS/MS method. PK parameters (AUCtau,ss,Cmax,ss) of LCZ696 analytes (LBQ657, valsartan) and HCTZ in plasma were determined using non-compartmental analysis, and the results were statisticallyevaluated. Results: The 90% CIs confidence intervals (CIs) for the geometric mean ratio for AUCtau,ss of HCTZ fell within the ( 0.8 - 1.25) range, while those of Cmax,ss (0.74, 0.70-0.78) fell outside the range, indicating Cmax,ss of HCTZ decreased by 26% when co-administered with LCZ696. Those for AUCtau,ss of LBQ657 fell within the range but the upper bound for Cmax,ss (1.19, 1.10-1.28) was outside the range, indicating Cmax of LBQ657 increased by 19%; the upper bound for valsartan exposures(AUCtau,ss: 1.14, 1.00-1.29; Cmax,ss: 1.16, 0.98-1.37) were above the range, indicating AUCtau,ss and Cmax,ss of valsartan increased by 14%and 16%, respectively. Conclusion: When LCZ696 400mg qd and HCTZ 25mg qd were co- administered, AUCtau,ss of HCTZ was unchanged but Cmax,ss decreased by 26%; AUCtau,ss of LBQ657 was unchanged but Cmax,ss increased by 19%; and lastly, AUCtau,ss and Cmax,ss of valsartan increased by 14%and 16%, respectively. LCZ696 400 mg qd was safe and well tolerated in healthy subjects when administered alone and in combination with HCTZ 25 mg qd.


2020 ◽  
Author(s):  
Fatou thiam ◽  
Gora Diop ◽  
Cedric Coulanges ◽  
Celine Derbois ◽  
Babacar Mbengue ◽  
...  

Abstract Background Several genetic polymorphisms were reported to be prevalent among populations living in tropical endemic regions and induce protection against malaria. In this study, we investigated the prevalence of key malaria-protective polymorphisms in G6PD and HBB genes in a Senegalese population. Methods We performed a retrospective study in 323 samples from patients recruited in hospitals located in three different endemic areas where malaria episodes were confirmed. Patients enrolled were classified in two groups: severe (153 patients) and uncomplicated malaria (170 patients). PCR and DNA sequencing assessed host genetic polymorphisms in HBB and G6PD. Using a multivariate regression and additive model, estimates the impact of human HBB and G6PD polymorphisms on malaria incidence were performed. Results We identified 12 SNPs in HBB gene. Among them, 6 SNPs (rs7946748, rs7480526, rs10768683, rs35209591, HbS (rs334) and rs713040) were detected with high frequencies in global population. The MAF of the sickle cell HbS polymorphism was estimated to 0.026, 0.069 and 0.035; and HbC polymorphism was estimated to be 0, 0.009, 0.029, in SM, UM and CTR group respectively. The MAF of G6PD deficiency polymorphisms such as G6PD-202 G>A were 0.022, 0.032 and 0.018 in SM, UM and CTR, respectively. Analysis of selected HbS polymorphism showed significant association with protection against severe malaria with a significant p-value = 0.033 (OR 0.38, 95%CI: 0.16–0.91). Surprisingly, HbC polymorphism is not a protective variant in our population. Finally, we found that the selected SNPs were associated to biological parameters such as PNE, PNB and lymphocytes. Conclusion Our data report at the first time the prevalence of HBB and G6PD mutations in senegalese population. These deficiencies are very common in West Africa endemic regions such as Gambia, Mali and Burkina Faso. Our findings show the important role of genetic factors in malaria outcome and these genetic markers could be good tools for malaria diagnosis and prognosis. Keywords : severe malaria, HBB, G6PD, Polymorphisms, Senegal, severe malaria.


2019 ◽  
Vol 74 (8) ◽  
pp. 2360-2364 ◽  
Author(s):  
Kristina M Brooks ◽  
Jose R Castillo-Mancilla ◽  
Joshua Blum ◽  
Ryan Huntley ◽  
Samantha MaWhinney ◽  
...  

AbstractBackgroundIntracellular tenofovir diphosphate concentrations are markedly increased in HIV/HCV coinfected individuals receiving tenofovir disoproxil fumarate (TDF) with sofosbuvir-containing treatment. Sofosbuvir may inhibit the hydrolysis of TDF to tenofovir, resulting in increased concentrations of the disoproxil or monoester forms, which may augment cell loading. We sought to quantify tenofovir disoproxil and monoester concentrations in individuals receiving TDF with and without ledipasvir/sofosbuvir.MethodsHIV/HCV coinfected participants receiving TDF-based therapy were sampled pre-dose and 1 and 4 h post-dose prior to and 4 weeks after initiating ledipasvir/sofosbuvir. Tenofovir disoproxil was not detectable. Tenofovir monoester in plasma and tenofovir diphosphate in PBMC and dried blood spots (DBS) were quantified using LC-MS/MS. Geometric mean ratios (week 4 versus baseline) and 95% CIs were generated for the pharmacokinetic parameters. P values reflect paired t-tests.ResultsTen participants had complete data. At baseline, geometric mean (95% CI) tenofovir monoester plasma concentrations at 1 and 4 h post-dose were 97.4 ng/mL (33.0–287.5) and 0.74 ng/mL (0.27–2.06), respectively. With ledipasvir/sofosbuvir, tenofovir monoester concentrations at 4 h post-dose were 5.02-fold higher (95% CI 1.40–18.05; P = 0.019), but did not significantly differ at 1 h post-dose (1.72-fold higher, 95% CI 0.25–11.78; P = 0.54), possibly due to absorption variability. Tenofovir diphosphate in PBMC and DBS were increased 2.80-fold (95% CI 1.71–4.57; P = 0.001) and 7.31-fold (95% CI 4.47–11.95; P < 0.0001), respectively, after 4 weeks of ledipasvir/sofosbuvir.ConclusionsTenofovir monoester concentrations were increased in individuals receiving TDF with ledipasvir/sofosbuvir, consistent with inhibition of TDF hydrolysis. Additional studies are needed to determine the clinical relevance of this interaction.


2014 ◽  
Vol 30 (S1) ◽  
pp. A137-A137 ◽  
Author(s):  
Abbey B. Evans ◽  
Jonathon Holt ◽  
Jeremy Nuttall ◽  
Robin Shattock

Author(s):  
E. A. Sоkоvа ◽  
R. A. Chilova ◽  
O. A. Demidova ◽  
K. O. Akopov

Spontaneous preterm birth is one of the most pressing issues in obstetrics, as it remains one of the leading causes of newborn morbidity and mortality. Pending issues of aetiology, pathogenesis, and absence of medicinal products indicated for the treatment of spontaneous preterm labour pose a challenge for rational pharmacotherapy. The paper presents the results of a scientific literature review on the problem of rational pharmacotherapy of spontaneous preterm labour using tocolytic drugs — calcium channel blockers, cyclooxygenase inhibitors. The paper summarises specific pharmacokinetic parameters of these drugs during pregnancy. It discusses pharmacogenetic aspects of using tocolytic drugs in pregnant women and their potential clinical effects. It was demonstrated that women with threatened miscarriage had high interindividual variability in nifedipine plasma concentrations depending on CYP3A5 genotype. It was shown that certain genetic polymorphisms of CYP2C9 may lead to an increased metabolic rate and an increase in indomethacin clearance resulting in the reduction of its efficacy. Yet, there is minimal research regarding this issue. Therefore, further research is needed to assess the impact of CYP3A5 and CYP2C9 genotypes on the efficacy and safety of nifedipine and indomethacin used as tocolytic drugs in obstetrics.


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