scholarly journals Lack of Effect of Simultaneously Administered Didanosine Encapsulated Enteric Bead Formulation (Videx EC) on Oral Absorption of Indinavir, Ketoconazole, or Ciprofloxacin

2002 ◽  
Vol 46 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Bharat D. Damle ◽  
Vanaja Mummaneni ◽  
Sanjeev Kaul ◽  
Catherine Knupp

ABSTRACT Didanosine formulation that contains a buffer to prevent it from acid-mediated degradation can result in a significant decrease in the oral absorption of certain drugs because of interactions with antacids. An enteric formulation of didanosine is unlikely to cause such drug interactions because it lacks antacids. This study was undertaken to determine whether the enteric bead formulation of didanosine (Videx EC) influences the bioavailability of indinavir, ketoconazole, and ciprofloxacin, three drugs that are representative of a broader class of drugs affected by interaction with antacids. Healthy subjects of either gender were enrolled in three separate open-label, single-dose, two-way crossover studies. Subjects were randomized to treatment A (800 mg of indinavir, 200 mg of ketoconazole, or 750 mg of ciprofloxacin) or treatment B (same dose of indinavir, ketoconazole, or ciprofloxacin, but with 400 mg of didanosine as an encapsulated enteric bead formulation). A lack of interaction was concluded if the 90% confidence interval (CI) of the ratio of the geometric means of log-transformed C max and AUC0-∞ values (i.e., values for the area under the concentration-time curve from time zero to infinity) of indinavir, ketoconazole, and ciprofloxacin were contained entirely between 0.75 and 1.33. For indinavir (n = 23), the point estimate (90% CI; minimum, maximum) of the ratios of C max and AUC0-∞ values were 0.99 (0.91, 1.06) and 0.96 (0.91, 1.02), respectively. In the ketoconazole study, 3 of 24 subjects showed anomalous absorption of ketoconazole (i.e., an ∼8-fold-lower AUC compared to historical data), which was the reference treatment. A post hoc analysis performed after these three subjects were excluded indicated that the point estimates (90% CI) of the ratios of Cmax and AUC0-∞ values were 0.99 (0.86, 1.14) and 0.97 (0.85, 1.10), respectively. For ciprofloxacin (n = 16), the point estimate (90% CI) of the ratios of C max and AUC0-∞ values were 0.92 (0.79, 1.07) and 0.91 (0.76, 1.08), respectively. All three studies clearly indicated a lack of interaction. The T max and t 1/2 for indinavir, ketoconazole, and ciprofloxacin were similar between treatments. Our results showed that the lack of interaction of didanosine encapsulated enteric bead formulation with indinavir, ketoconazole, and ciprofloxacin indicates that this enteric formulation of didanosine can be concomitantly administered with drugs whose bioavailability is known to be reduced by interaction with antacids.

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Monica L. Carten ◽  
Jennifer J. Kiser ◽  
Awewura Kwara ◽  
Samantha Mawhinney ◽  
Susan Cu-Uvin

Objectives. Compare the Plan B levonorgestrel (LNG) area under the concentration- time curve (AUC12) prior to and with efavirenz (EFV).Design. Prospective, open-label, single-arm, equivalence study.Methods. Healthy HIV-negative subjects underwent 12 hr intensive pharmacokinetic (PK) sampling following single dose LNG alone and after 14 days of EFV. Geometric means, Geometric Mean Ratios, and 90% confidence intervals (CI) are reported for PK Parameters.T-tests were utilized. Clinical parameters and liver function tests (LFTs) were assessed.Results. 24 women enrolled and 21 completed the study. With EFV, LNG AUC12was reduced 56% (95% CI: 49%, 62%) from 42.9 to 17.8 ng*hr/mL, and maximum concentration (Cmax⁡) was reduced 41% (95% CI: 33%, 50%) from 8.4 to 4.6 ng/mL. LNG was well tolerated with no grade 3 or 4 treatment-related toxicities.Conclusions. EFV significantly reduced LNG exposures. Higher LNG doses may be required with EFV. These results reinforce the importance of effective contraception in women taking EFV.


2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 316-316
Author(s):  
Karen J. Ferrante ◽  
Douglas B Jacoby ◽  
Daryl Sonnichsen

316 Background: Galeterone (gal) is a semisynthetic steroid that targets androgen receptor (AR) signaling via increased AR protein degradation, inhibition of CYP17 activity, and inhibition of androgen binding to AR. Gal is a novel potential treatment for prostate cancer. In vitro, gal competitively inhibits CYP3A4 (IC50 = 5.5 μM; midazolam as substrate). This clinical study evaluated whether multiple daily doses of gal alter the single-dose PK of midazolam, a sensitive probe substrate for functional CYP3A4 intestinal and hepatic activity. Methods: In an open-label, fixed sequence, DDI study, 18 healthy male volunteers received midazolam 2 mg Day 1 and Day 5 and gal 2550 mg Days 2-5. Midazolam plasma PK was determined on Days 1 and 5. The effect of gal on the natural log-transformed Cmax, AUC0-inf, and AUC0-t of midazolam was assessed with a linear mixed-effects model; point estimates for geometric means, geometric mean ratios with 90% confidence intervals were determined. Safety was also monitored. Results: The Tmax of midazolam was not altered by gal coadministration. The < 2-fold increases in midazolam Cmax and AUCs were statistically significant. For Cmax, the point estimate of the geometric least squares (LS) mean ratio between the 2 treatments was 1.25 (90% CI: 1.05, 1.48). Higher ratios were observed for the AUC ratios, with LS mean ratio for AUC0-t of 1.57 (90% CI: 1.43, 1.73) and for AUC0-inf of 1.58 (90% CI: 1.42, 1.75). The mean midazolam t1/2 was approximately 76% higher with gal coadministration. Multiple doses of gal were well tolerated with no apparent effect on the safety of midazolam. Conclusions: Per FDA guidance, < 2-fold increases in midazolam Cmax and AUCs observed with gal coadministration support its classification as a weak inhibitor of CYP3A4. Given the similar or higher in vitro IC50’s for CYP2C8 and CYP2C19, respectively, a comparable or lesser degree of enzyme inhibition is expected for gal 2550 mg daily. Based on these results, concurrent CYP3A4, CYP2C8, and CYP2C19 substrates are not contraindicated in patients taking gal; caution is advised in patients receiving or initiating sensitive CYP3A4, CYP2C8, and CYP2C19 substrates, especially those with a narrow therapeutic range.


2017 ◽  
Vol 22 (5) ◽  
pp. 434-446 ◽  
Author(s):  
Lawrence J. Lesko ◽  
Elliot Offman ◽  
Christine Taylor Brew ◽  
Dahlia Garza ◽  
Wade Benton ◽  
...  

Introduction: Patiromer is a potassium-binding polymer that is not systemically absorbed; however, it may bind coadministered oral drugs in the gastrointestinal tract, potentially reducing their absorption. Methods: Twelve randomized, open-label, 3-period, 3-sequence crossover studies were conducted in healthy volunteers to evaluate the effect of patiromer (perpetrator drug) on absorption and single-dose pharmacokinetics (PK) of drugs (victims) that might be commonly used with patiromer. Subjects received victim drug alone, victim drug administered together with patiromer 25.2 g (highest approved dose), and victim drug administered 3 hours before patiromer 25.2 g. The primary PK endpoints were area under the curve (AUC), extrapolated to infinity (AUC0-∞), and maximum concentration ( Cmax). Results were reported as 90% confidence intervals (CIs) about the geometric mean AUC0-∞ and Cmax ratios with prespecified equivalence limits of 80% to 125%. Results: Overall, 370 subjects were enrolled, with 365 receiving ≥1 dose of patiromer; 351 subjects completed the studies and all required treatments. When coadministered with patiromer, the 90% CIs for AUC0-∞ remained within 80% to 125% for 9 drugs (amlodipine, cinacalcet, clopidogrel, furosemide, lithium, metoprolol, trimethoprim, verapamil, and warfarin). The AUC0-∞ point estimate ratios for levothyroxine and metformin with patiromer coadministration were ≥80%, with the lower bounds of the 90% CIs at 76.8% and 72.8%, respectively. For ciprofloxacin, the point estimate for AUC0-∞ was 71.5% (90% CI: 65.3-78.4). For 8 of 12 drugs, point estimates for Cmax were ≥80% with patiromer coadministration; for ciprofloxacin, clopidogrel, metformin, and metoprolol, the point estimates were <80%. When patiromer was administered 3 hours after each victim drug, the 90% CIs for AUC0-∞ and Cmax for each drug were within the prespecified 80% to 125% limits. Conclusion: For 9 of the 12 drugs coadministered with patiromer, there were no clinically significant drug–drug interactions. For 3 drugs (ciprofloxacin, levothyroxine, and metformin), a 3-hour separation between patiromer and their administration resulted in no clinically significant drug–drug interactions.


2011 ◽  
Vol 55 (5) ◽  
pp. 2290-2296 ◽  
Author(s):  
Thomas N. Kakuda ◽  
Samantha Abel ◽  
John Davis ◽  
Julia Hamlin ◽  
Monika Schöller-Gyüre ◽  
...  

ABSTRACTThe effects of darunavir-ritonavir at 600 and 100 mg twice daily (b.i.d.) alone, 200 mg of etravirine b.i.d. alone, or 600 and 100 mg of darunavir-ritonavir b.i.d. with 200 mg etravirine b.i.d. at steady state on the steady-state pharmacokinetics of maraviroc, and vice versa, in healthy volunteers were investigated in two phase I, randomized, two-period crossover studies. Safety and tolerability were also assessed. Coadministration of 150 mg maraviroc b.i.d. with darunavir-ritonavir increased the area under the plasma concentration-time curve from 0 to 12 h (AUC12) for maraviroc 4.05-fold relative to 150 mg of maraviroc b.i.d. alone. Coadministration of 300 mg maraviroc b.i.d. with etravirine decreased the maraviroc AUC12by 53% relative to 300 mg maraviroc b.i.d. alone. Coadministration of 150 mg maraviroc b.i.d. with etravirine-darunavir-ritonavir increased the maraviroc AUC123.10-fold relative to 150 mg maraviroc b.i.d. alone. Maraviroc did not significantly affect the pharmacokinetics of etravirine, darunavir, or ritonavir. Short-term coadministration of maraviroc with darunavir-ritonavir, etravirine, or both was generally well tolerated, with no safety issues reported in either trial. Maraviroc can be coadministered with darunavir-ritonavir, etravirine, or etravirine-darunavir-ritonavir. Maraviroc should be dosed at 600 mg b.i.d. with etravirine in the absence of a potent inhibitor of cytochrome P450 3A (CYP3A) (i.e., a boosted protease inhibitor) or at 150 mg b.i.d. when coadministered with darunavir-ritonavir with or without etravirine.


2007 ◽  
Vol 51 (8) ◽  
pp. 2982-2984 ◽  
Author(s):  
Mary B. Wire ◽  
Charles H. Ballow ◽  
Julie Borland ◽  
Mark J. Shelton ◽  
Yu Lou ◽  
...  

ABSTRACT Plasma ketoconazole (KETO), amprenavir (APV), and ritonavir (RTV) pharmacokinetics were evaluated in 15 healthy subjects after being treated with KETO at 200 mg once daily (QD), fosamprenavir (FPV)/RTV at 700/100 mg twice daily (BID), and then KETO at 200 mg QD plus FPV/RTV at 700/100 mg BID in this open-label study. The KETO area under the concentration-time curve at steady state was increased 2.69-fold with FPV/RTV. APV exposure was unchanged, and RTV exposure was slightly increased.


2019 ◽  
Vol 104 (6) ◽  
pp. e49.2-e49
Author(s):  
M Pfiffner ◽  
V Gotta ◽  
E Berger-Olah ◽  
M Pfister ◽  
P Vonbach

BackgroundNalbuphine is a mixed agonist-antagonist opioid analgesic agent frequently used in paediatrics, and licensed for parenteral use only. Intranasal delivery could be a safe, effective and non-invasive alternative, especially in infants in the acute setting. However, pharmacokinetic (PK) data for this route of administration is completely lacking. The aim of this study was to assess PK of nalbuphine in infants 1–3 months after single intravenous (0.05 mg/kg) and intranasal (0.1 mg/kg) application, respectively.MethodsWe conducted a prospective, single centre, open-label pharmacokinetic study in infants 1–3 months undergoing sepsis workup in the emergency unit. Included infants received alternating nalbuphine as 0.05 mg/kg intravenous bolus or as 0.1 mg/kg intranasal spray. PK samples were taken at 3 pre-defined time points (15, 30 and max. 240 min post-dose before discharge). Area under the concentration-time curve (AUC0-Tlast, and AUC0-infinity for i.v.) was calculated using noncompartmental analysis and was compared between groups using Wilcoxon test. Further parameters derived included maximum concentration (Cmax), time of maximum concentration (Tmax for i.n.) and terminal half-life (t1/2).ResultsA total of 31 patients were included in the analysis. Median age was 55 days [interquartile range 38–63] in the intranasal (N=20) and 42 [37–76] days in the iv group (N=11). Median AUC0-Tlast was 7.6 (5.4–10.4) mcg*h/L following intranasal versus 7.9 (6.0–14.7) mcg*h/L for iv administration (p=0.46). AUC0-Tlast (i.v.) covered 80 [68–83]% of AUC0-infinity. Median Cmax was 4.5 [3.5–5.6] mcg/L (i.n.) versus 6.5 [5.3–15.9] mcg/L (i.v.) (p=0.014), t1/22.4 [1.3–2.8] h (i.n.) versus 1.3 [1.1–1.5] h (i.v.) (p=0.021). Tmax occurred 37 [32–65] min after intranasal administration.ConclusionThis first PK study of intranasal nalbuphine in infants suggests that 0.1 mg/kg i.n. dosing provides similar exposure as 0.05 mg/kg i.v. in infants in terms of AUC, and hence intranasal bioavailability close to 50%.Disclosure(s)Nothing to disclose


1999 ◽  
Vol 43 (5) ◽  
pp. 1152-1155 ◽  
Author(s):  
Kevin W. Garey ◽  
Charles A. Peloquin ◽  
Paul G. Godo ◽  
Anne N. Nafziger ◽  
Guy W. Amsden

ABSTRACT This randomized, open-label, crossover study was conducted to investigate whether the coadministration of zafirlukast would affect the pharmacokinetics of azithromycin, clarithromycin, or 14-hydroxyclarithromycin (14-OHC). Twelve healthy subjects (six males and six females) received single 500-mg doses of azithromycin and clarithromycin with and without zafirlukast given to a steady-state concentration. Blood was collected prior to all macrolide doses and for 3 and 10 days after each clarithromycin and azithromycin dose, respectively. Serum was assayed for azithromycin, clarithromycin, and 14-OHC concentrations by validated high-performance liquid chromatography assay systems. Data analyses were done by noncompartmental and nonparametric methods. Analysis of the patients indicated that the addition of steady-state concentrations of zafirlukast did not significantly alter the pharmacokinetic parameters of or overall exposure (based on the area under the concentration-time curve) to azithromycin, clarithromycin, and 14-OHC. While zafirlukast is a known inhibitor of CYP3A4, it does not appear to exert a clinically or statistically significant pharmacokinetic effect on azithromycin, clarithromycin, or 14-OHC.


2014 ◽  
Vol 58 (12) ◽  
pp. 7340-7346 ◽  
Author(s):  
Borimas Hanboonkunupakarn ◽  
Elizabeth A. Ashley ◽  
Podjanee Jittamala ◽  
Joel Tarning ◽  
Sasithon Pukrittayakamee ◽  
...  

ABSTRACTDihydroartemisinin-piperaquine is an artemisinin-based combination treatment (ACT) recommended by the WHO for uncomplicatedPlasmodium falciparummalaria, and it is being used increasingly for resistant vivax malaria where combination with primaquine is required for radical cure. The WHO recently reinforced its recommendations to add a single dose of primaquine to ACTs to reduceP. falciparumtransmission in low-transmission settings. The pharmacokinetics of primaquine and dihydroartemisinin-piperaquine were evaluated in 16 healthy Thai adult volunteers in a randomized crossover study. Volunteers were randomized to two groups of three sequential hospital admissions to receive 30 mg (base) primaquine, 3 tablets of dihydroartemisinin-piperaquine (120/960 mg), and the drugs together at the same doses. Blood sampling was performed over 3 days following primaquine and 36 days following dihydroartemisinin-piperaquine dosing. Pharmacokinetic assessment was done with a noncompartmental approach. The drugs were well tolerated. There were no statistically significant differences in dihydroartemisinin and piperaquine pharmacokinetics with or without primaquine. Dihydroartemisinin-piperaquine coadministration significantly increased plasma primaquine levels; geometric mean ratios (90% confidence interval [CI]) of primaquine combined versus primaquine alone for maximum concentration (Cmax), area under the concentration-time curve from 0 h to the end of the study (AUC0–last), and area under the concentration-time curve from 0 h to infinity (AUC0–∞) were 148% (117 to 187%), 129% (103 to 163%), and 128% (102 to 161%), respectively. This interaction is similar to that described recently with chloroquine and may result in an enhanced radical curative effect. (This study has been registered at ClinicalTrials.gov under registration no. NCT01525511.)


2018 ◽  
Vol 7 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Kenneth Todd Moore, MS ◽  
Holly D. Adams, MS ◽  
Jaya Natarajan, PhD ◽  
Jay Ariyawansa, MS ◽  
Henry M. Richards, MD

Objectives: Fentanyl is a potent synthetic opioid used for the management of chronic pain. A newer transdermal matrix system was developed and compared with a reservoir system used in the United States.Setting: An open-label, single-center, randomized, two-period crossover study was conducted to evaluate the bioequivalence of the transdermal matrix system to the transdermal reservoir system. Seventy-four subjects completed treatment with both the reservoir system (100 μg/h) and the matrix system (100 μg/h), each applied for 72 hours. After application of the first system, subjects completed a 9-day washout and then crossed over to receive the other system for another 72 hours.Main outcome measure: Blood samples for the determination of serum fentanyl concentrations were taken in each treatment period for up to 120 hours following application.Results: The ratios of geometric means for maximum fentanyl concentration (Cmax) and area under the concentration-time curve (AUClast and AUC∞ ) were 106 percent, 110 percent, and 110 percent, respectively. The 90% confidence intervals for the ratios of the geometric means were contained within the bioequivalence criteria of 80-125 percent. The matrix system adhered well to skin. Systemic and topical safety profiles were comparable between treatments.Conclusions: The transdermal fentanyl matrix system adhered well, was well tolerated, and produced systemic exposures of fentanyl that were bioequivalent to the reservoir system.


2016 ◽  
Vol 60 (10) ◽  
pp. 6252-6259 ◽  
Author(s):  
John S. Bradley ◽  
Jon Armstrong ◽  
Antonio Arrieta ◽  
Raafat Bishai ◽  
Shampa Das ◽  
...  

ABSTRACTThis study aimed to investigate the pharmacokinetics (PK), safety, and tolerability of a single dose of ceftazidime-avibactam in pediatric patients. A phase I, multicenter, open-label PK study was conducted in pediatric patients hospitalized with an infection and receiving systemic antibiotic therapy. Patients were enrolled into four age cohorts (cohort 1, ≥12 to <18 years; cohort 2, ≥6 to <12 years; cohort 3, ≥2 to <6 years; cohort 4, ≥3 months to <2 years). Patients received a single 2-h intravenous infusion of ceftazidime-avibactam (cohort 1, 2,000 to 500 mg; cohort 2, 2,000 to 500 mg [≥40 kg] or 50 to 12.5 mg/kg [<40 kg]; cohorts 3 and 4, 50 to 12.5 mg/kg). Blood samples were collected to describe individual PK characteristics for ceftazidime and avibactam. Population PK modeling was used to describe characteristics of ceftazidime and avibactam PK across all age groups. Safety and tolerability were assessed. Thirty-two patients received study drug. Mean plasma concentration-time curves, geometric mean maximum concentration (Cmax), and area under the concentration-time curve from time zero to infinity (AUC0–∞) were similar across all cohorts for both drugs. Six patients (18.8%) reported an adverse event, all mild or moderate in intensity. No deaths or serious adverse events occurred. The single-dose PK of ceftazidime and avibactam were comparable between each of the 4 age cohorts investigated and were broadly similar to those previously observed in adults. No new safety concerns were identified. (This study has been registered at ClinicalTrials.gov under registration no. NCT01893346.)


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