Steady-state pharmacokinetics of darunavir/ritonavir and pitavastatin when co-administered to healthy adult volunteers.

BACKGROUND: The treatment of hyperlipidaemia in human immunodeficiency virus (HIV)-infected patients has become increasingly important. However, treatment options are limited because of the drug-drug interaction between certain statins and HIV medications metabolized by cytochrome P450 (CYP) enzymes. OBJECTIVES: The primary objective was to investigate the steady-state pharmacokinetics of pitavastatin when co-administered with darunavir/ritonavir. The secondary objective was to investigate the steady-state pharmacokinetics of both darunavir and ritonavir when co-administered with pitavastatin. METHODS: This was a single-centre, open-label, multi-dose, fixed-sequence study in HIV seronegative healthy volunteers. Pitavastatin 4 mg was administered once daily on days 1-5 and on days 12-16, and darunavir 800 mg/ritonavir 100 mg once daily on days 6-16. Pharmacokinetic blood sampling was performed on days 5, 11 and 16. No significant interaction was concluded if the 90 % confidence intervals (CIs) of the geometric mean ratios (GMRs) for total exposure [i.e. the area under the plasma concentration-time curve over a dosing interval at steady state (AUC(0-τ))] and for peak exposure [i.e. the maximum plasma concentration (C(max))] of the two treatments were within the 80-125 % range. RESULTS: Twenty-eight subjects (mean age 30.5 years) were enrolled, and pharmacokinetic data were available for 27 subjects. For pitavastatin, the GMRs and 90 % CIs for the AUC(0-τ) and C(max) ratios with co-administration were 0.74 (0.69-0.80) and 0.96 (0.84-1.09), respectively. For both darunavir and ritonavir, the 90 % CIs for the AUC(0-τ) and C max ratios were within 80-125 % with pitavastatin co-administration. No significant safety issues were reported. CONCLUSION: Darunavir/ritonavir decreased total exposure to pitavastatin by 26 %, while peak exposures were similar. Pitavastatin did not influence the pharmacokinetics of darunavir or ritonavir. There is limited interaction between pitavastatin and darunavir/ritonavir.

Effects of steady-state lopinavir/ritonavir on the pharmacokinetics of pitavastatin in healthy adult volunteers.

OBJECTIVES: Pitavastatin, a statin recently approved in the United States, has a potential benefit of reduced risk of cytochrome P450 (CYP)-mediated drug-drug interaction due to minimal metabolism by the CYP system. The primary objective was to investigate pharmacokinetic (PK) effects of lopinavir/ritonavir 400 mg/100 mg twice daily on pitavastatin 4 mg when coadministered. DESIGN: This was an open-label one-arm study. METHOD: Pitavastatin 4 mg was administered once daily (days 1-5 and days 20-24). Lopinavir/ritonavir 400 mg/100 mg was administered twice daily (days 9-24). Plasma samples for PK assessments were collected on days 5, 19, and 24. Plasma concentrations of analytes were determined by liquid chromatography with tandem mass spectrometric detection methods. RESULTS: PK data were available for 23 of 24 subjects enrolled. For pitavastatin, area under the concentration time curve (AUC0-τ) and maximum concentration (C(max)) were 136.8 ± 52.9 ng·h(-1)·mL(-1) and 58.6 ± 30.4 ng/mL, respectively, when given alone, versus 113.9 ± 53.8 ng·h(-1)·mL(-1) and 58.2 ± 32.7 ng/mL when combined with lopinavir/ritonavir. The geometric mean ratio for AUC(0-τ) for pitavastatin with lopinavir/ritonavir versus pitavastatin alone was 80.0 (90% confidence interval: 73.4 to 87.3) and C(max) was 96.1 (90% confidence interval: 83.6 to 110.4). Median T(max) of pitavastatin was approximately 0.5 hours for both treatments. The PK effect of pitavastatin on lopinavir/ritonavir was minimal. No significant safety issues were reported. CONCLUSIONS: The effect on exposures when pitavastatin and lopinavir/ritonavir are coadministered was minimal. Concomitant use of pitavastatin and lopinavir/ritonavir was safe and well tolerated in healthy adult volunteers.

Pharmacokinetics and absorption of posaconazole oral suspension under various gastric conditions in healthy volunteers.

A four-part, randomized, crossover study with healthy subjects evaluated the effects of gastric pH, the dosing frequency and prandial state, food consumption timing, and gastric motility on the absorption of posaconazole. In part 1, a single dose (SD) of posaconazole (400 mg) was administered alone or with an acidic beverage or a proton pump inhibitor (PPI), or both. In part 2, posaconazole (400 mg twice daily and 200 mg four times daily) was administered for 7 days with and without a nutritional supplement (Boost). In part 3, an SD of posaconazole (400 mg) was administered while the subjects were fasting and before, during, and after a high-fat meal. In part 4, an SD of posaconazole (400 mg) and the nutritional supplement were administered alone, with metoclopramide, and with loperamide. Compared to the results obtained with posaconazole alone, administration with an acidic beverage increased the posaconazole maximum concentration in plasma (C(max)) and the area under the concentration-time curve (AUC) by 92% and 70%, respectively, whereas a higher gastric pH decreased the posaconazole C(max) and AUC by 46% and 32%, respectively. Compared to the results obtained with posaconazole alone, posaconazole at 400 mg or at 200 mg plus the nutritional supplement increased the posaconazole C(max) and AUC by 65% and 66%, respectively, and by up to 137% and 161%, respectively. Administration before a high-fat meal increased the C(max) and the AUC by 96% and 111%, respectively, while administration during and after the meal increased the C(max) and the AUC by up to 339% and 387%, respectively. Increased gastric motility decreased the C(max) and the AUC by 21% and 19%, respectively. Strategies to maximize posaconazole exposure in patients with absorption difficulties include administration with or after a high-fat meal, with any meal or nutritional supplement, with an acidic beverage, or in divided doses and the avoidance of proton pump inhibitors.