scholarly journals Pharmacokinetic Interactions between the Hormonal Emergency Contraception, Levonorgestrel (Plan B), and Efavirenz

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.

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.


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.)


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.)


2021 ◽  
Author(s):  
Ramesh Boinpally ◽  
Abhijeet Jakate ◽  
Matthew Butler ◽  
Antonia Periclou

Aim: To evaluate pharmacokinetic interactions of atogepant with sumatriptan, an open-label, randomized, crossover study was conducted. Patients & methods: Thirty healthy adults received atogepant 60 mg, sumatriptan 100 mg, or coadministered drugs. Primary end point was geometric mean ratios (GMRs) and 90% CIs of interventions for area under the plasma concentration–time curve from time 0 to t (AUC0-t) or infinity (AUC0-∞) and peak plasma concentration (Cmax). Results: Atogepant GMRs for AUC0-t and AUC0-∞ versus with sumatriptan were within 90% CI 0.80–1.25, indicating no interaction; atogepant Cmax was reduced by 22% (GMR: 0.78; 90% CI: 0.69–0.89) with sumatriptan. Sumatriptan GMRs for AUC0-t, AUC0-∞ and Cmax versus with atogepant were within 90% CI 0.80–1.25. Conclusion: Atogepant with sumatriptan had no clinically relevant pharmacokinetic interactions.


2017 ◽  
Vol 32 (6) ◽  
pp. 360-366
Author(s):  
Dhiraj Abhyankar ◽  
Ashish Shedage ◽  
Milind Gole ◽  
Preeti Raut

Objective: To assess the bioequivalence of generic formulation of rivastigmine (test) and Exelon (reference). Methods: This randomized, open-label, 2-period, single-dose, 2-treatment, 2-sequence, crossover study was conducted in 40 healthy men under fed condition. Participants were randomized to receive a single dose of Exelon or rivastigmine capsule. Results: A total of 31 participants completed the study. Area under the concentration–time curve from time zero to time t (AUC0- t) and area under the concentration–time curve from time zero to infinity (AUC0-∞) for Exelon (mean [standard deviation], h·ng/mL) were 126.40 (56.95) and 129.46 (59.94), respectively, while they were 122.73 (43.46) and 125.08 (45.39) for rivastigmine. Geometric mean ratios of rivastigmine/Exelon were 99.17% for AUC0- t, 98.81% for AUC0-∞, and 105% for maximum observed plasma concentration ( Cmax). The 90% confidence intervals (CIs) were 94.14% to 104.46%, 93.77% to 104.12%, and 93.08% to 118.44%, respectively. Both formulations were well tolerated. Conclusion: The generic and reference formulations were bioequivalent, as the 90% CIs for Cmax, AUC0- t, and AUC0-∞ were within the range of 80% to 125%.


2008 ◽  
Vol 53 (1) ◽  
pp. 162-173 ◽  
Author(s):  
Charles J. L. la Porte ◽  
John P. Sabo ◽  
Mabrouk Elgadi ◽  
D. William Cameron

ABSTRACT Three separate controlled, two-period studies with healthy volunteers assessed the pharmacokinetic interactions between tipranavir-ritonavir (TPV/r) in a 500/200-mg dose and 500 mg of clarithromycin (CLR), 100 mg of fluconazole (FCZ), or 150 mg of rifabutin (RFB). The CLR study was conducted with 24 subjects. The geometric mean ratios (GMR) and 90% confidence intervals (90% CI; given in parentheses) of the areas under the concentration-time curve (AUC), the maximum concentrations of the drugs in serum (C max), and the concentrations in serum at 12 h postdose (Cp12h) for multiple-dose TPV/r and multiple-dose CLR, indicating the effect of TPV/r on the CLR parameters, were 1.19 (1.04-1.37), 0.95 (0.83-1.09), and 1.68 (1.42-1.98), respectively. The formation of the metabolite 14-OH-CLR was decreased by 95% in the presence of TPV, and the TPV AUC increased 66% compared to that for human immunodeficiency virus (HIV)-negative historical controls. The FCZ study was conducted with 20 subjects. The GMR (and 90% CI) of the AUC, C max, and Cp24h, indicating the effect of multiple-dose TPV/r on the multiple-dose FCZ parameters, were 0.92 (0.88-0.95), 0.94 (0.91-0.98), and 0.89 (0.85-0.92), respectively. The TPV AUC increased by 50% compared to that for HIV-negative historical controls. The RFB study was conducted with 24 subjects. The GMR (and 90% CI) of the AUC, C max, and Cp12h for multiple-dose TPV/r and single-dose RFB, indicating the effect of TPV/r on the RFB parameters, were 2.90 (2.59-3.26), 1.70 (1.49-1.94), and 2.14 (1.90-2.41), respectively. The GMR (and 90% CI) of the AUC, C max, and Cp12h of TPV/r and RFB with 25-O-desacetyl-RFB were 4.33 (3.86-4.86), 1.86 (1.63-2.12), and 2.76 (2.44-3.12), respectively. Coadministration of TPV with a single dose of RFB resulted in a 16% increase in the TPV Cp12h compared to that for TPV alone. In the general population, no dose adjustments are necessary for the combination of TPV/r and CLR or FCZ. Combining TPV/r with RFB should be done with caution, while toxicity and RFB drug levels should be monitored. Study medications were generally well-tolerated in these studies.


2009 ◽  
Vol 53 (10) ◽  
pp. 4385-4392 ◽  
Author(s):  
P. A. Pham ◽  
C. J. L. la Porte ◽  
L. S. Lee ◽  
R. van Heeswijk ◽  
J. P. Sabo ◽  
...  

ABSTRACT To identify pharmacokinetic (PK) drug-drug interactions between tipranavir-ritonavir (TPV/r) and rosuvastatin and atorvastatin, we conducted two prospective, open-label, single-arm, two-period studies. The geometric mean (GM) ratio was 1.37 (90% confidence interval [CI], 1.15 to 1.62) for the area under the concentration-time curve (AUC) for rosuvastatin and 2.23 (90% CI, 1.83 to 2.72) for the maximum concentration of drug in serum (C max) for rosuvastatin with TPV/r at steady state versus alone. The GM ratio was 9.36 (90% CI, 8.02 to 10.94) for the AUC of atorvastatin and 8.61 (90% CI, 7.25 to 10.21) for the C max of atorvastatin with TPV/r at steady state versus alone. Tipranavir PK parameters were not affected by single-dose rosuvastatin or atorvastatin. Mild gastrointestinal intolerance, headache, and mild reversible liver enzyme elevations (grade 1 and 2) were the most commonly reported adverse drug reactions. Based on these interactions, we recommend low initial doses of rosuvastatin (5 mg) and atorvastatin (10 mg), with careful clinical monitoring of rosuvastatin- or atorvastatin-related adverse events when combined with TPV/r.


2014 ◽  
Vol 58 (7) ◽  
pp. 4020-4025 ◽  
Author(s):  
Walter K. Kraft ◽  
Peter S. Chang ◽  
Marlou L. P. S. van Iersel ◽  
Hetty Waskin ◽  
Gopal Krishna ◽  
...  

ABSTRACTPosaconazole oral suspension is an extended-spectrum triazole that should be taken with food to maximize absorption. A new posaconazole tablet formulation has demonstrated improved bioavailability over the oral suspension in healthy adults in a fasting state. This study evaluated the effects of concomitant medications altering gastric pH (antacid, ranitidine, and esomeprazole) and gastric motility (metoclopramide) on the pharmacokinetics of posaconazole tablets. This was a prospective open-label 5-way crossover study in 20 healthy volunteers. In each treatment period, a single 400-mg dose (4 100-mg tablets) of posaconazole was administered alone or with 20 ml antacid (2 g of aluminum hydroxide and 2 g of magnesium hydroxide), ranitidine (150 mg), esomeprazole (40 mg), or metoclopramide (15 mg). There was a ≥10-day washout between treatment periods. Posaconazole exposure, time to maximum concentration of drug in serum (Tmax), and apparent terminal half-life (t1/2) were similar when posaconazole was administered alone or with medications affecting gastric pH and gastric motility. Geometric mean ratios (90% confidence intervals [CIs]) of the area under the concentration-time curve from time zero to infinity (AUC0–inf) (posaconazole with medications affecting gastric pH and gastric motility versus posaconazole alone) were 1.03 (0.88–1.20) with antacid, 0.97 (0.84–1.12) with ranitidine, 1.01 (0.87–1.17) with esomeprazole, and 0.93 (0.79–1.09) with metoclopramide. Geometric mean ratios (90% CIs) of the maximum concentration of drug in serum (Cmax) were 1.06 (0.90–1.26) with antacid, 1.04 (0.88–1.23) with ranitidine, 1.05 (0.89–1.24) with esomeprazole, and 0.86 (0.73–1.02) with metoclopramide. In summary, in healthy volunteers, the pharmacokinetics of a single 400-mg dose of posaconazole tablets was not altered to a clinically meaningful extent when posaconazole was administered alone or with medications affecting gastric pH or gastric motility.


2010 ◽  
Vol 55 (1) ◽  
pp. 326-330 ◽  
Author(s):  
José Moltó ◽  
Marta Valle ◽  
Cristina Miranda ◽  
Samandhy Cedeño ◽  
Eugenia Negredo ◽  
...  

ABSTRACTThe aim of this open-label, fixed-sequence study was to investigate the potential ofEchinacea purpurea, a commonly used botanical supplement, to interact with the boosted protease inhibitor darunavir-ritonavir. Fifteen HIV-infected patients receiving antiretroviral therapy including darunavir-ritonavir (600/100 mg twice daily) for at least 4 weeks were included.E. purpurearoot extract capsules were added to the antiretroviral treatment (500 mg every 6 h) from days 1 to 14. Darunavir concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, and 12 h after a morning dose of darunavir-ritonavir on days 0 (darunavir-ritonavir) and 14 (darunavir-ritonavir plus echinacea). Individual darunavir pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 with the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 49 (range, 43 to 67) years, and the body mass index was 24.2 (range, 18.7 to 27.5) kg/m2. Echinacea was well tolerated, and all participants completed the study. The GMR for darunavir coadministered with echinacea relative to that for darunavir alone was 0.84 (90% CI, 0.63-1.12) for the concentration at the end of the dosing interval, 0.90 (90% CI, 0.74-1.10) for the area under the concentration-time curve from 0 to 12 h, and 0.98 (90% CI, 0.82-1.16) for the maximum concentration. In summary, coadministration ofE. purpureawith darunavir-ritonavir was safe and well tolerated. Individual patients did show a decrease in darunavir concentrations, although this did not affect the overall darunavir or ritonavir pharmacokinetics. Although no dose adjustment is required, monitoring darunavir concentrations on an individual basis may give reassurance in this setting.


2010 ◽  
Vol 54 (7) ◽  
pp. 2965-2973 ◽  
Author(s):  
C. Kityo ◽  
A. S. Walker ◽  
L. Dickinson ◽  
F. Lutwama ◽  
J. Kayiwa ◽  
...  

ABSTRACT We evaluated the pharmacokinetics of lopinavir-ritonavir with and without nonnucleoside reverse transcriptase inhibitors (NNRTIs) in Ugandan adults. The study design was a three-period crossover study (3 tablets [600 mg of lopinavir/150 mg of ritonavir {600/150 mg}], 4 capsules [533/133 mg], and 2 tablets [400/100 mg] twice a day [BD]; n = 40) of lopinavir-ritonavir with NNRTIs and a parallel one-period study (2 tablets BD; n = 20) without NNRTIs. Six-point pharmacokinetic sampling (0, 2, 4, 6, 8, and 12 h) was undertaken after observed intake with a standardized breakfast. Ugandan DART trial participants receiving efavirenz (n = 20), nevirapine (n = 18), and no NNRTI (n = 20) had median ages of 41, 35, and 37 years, respectively, and median weights of 60, 64, and 63 kg, respectively. For the no-NNRTI group, the geometric mean (percent coefficient of variation [%CV]) lopinavir area under the concentration-time curve from 0 to 12 h (AUC0-12) was 110.1 (34%) μg·h/liter. For efavirenz, the geometric mean lopinavir AUC0-12 (%CV) values were 91.8 μg·h/liter (58%), 65.7 μg·h/liter (39%), and 54.0 μg·h/liter (65%) with 3 tablets, 4 capsules, and 2 tablets BD, respectively, with corresponding (within-individual) geometric mean ratios (GMR) for 3 and 2 tablets versus 4 capsules of 1.40 (90% confidence interval [CI], 1.18 to 1.65; P = 0.002) and 0.82 (90% CI, 0.68 to 0.99; P = 0.09), respectively, and the apparent oral clearance (CL/F) values were reduced by 58% and 1%, respectively. For nevirapine, the geometric mean lopinavir AUC0-12 (%CV) values were 112.9 μg·h/liter (30%), 68.1 μg·h/liter (53%), and 61.5 μg·h/liter (52%), respectively, with corresponding GMR values of 1.66 (90% CI, 1.46 to 1.88; P < 0.001) and 0.90 (90% CI, 0.77 to 1.06; P = 0.27), respectively, and the CL/F was reduced by 57% and 7%, respectively. Higher values for the lopinavir concentration at 12 h (C 12) were observed with 3 tablets and efavirenz-nevirapine (P = 0.04 and P = 0.0005, respectively), and marginally lower C 12 values were observed with 2 tablets and efavirenz-nevirapine (P = 0.08 and P = 0.26, respectively). These data suggest that 2 tablets of lopinavir-ritonavir BD may be inadequate when dosed with NNRTIs in Ugandan adults, and the dosage should be increased by the addition of an additional adult tablet or a half-dose tablet (100/25 mg), where available.


Sign in / Sign up

Export Citation Format

Share Document