Journal of clinical pharmacology
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Comparative Study
Comparing the Incidence of Febrile Neutropenia Resulting in Hospital Admission Between the Branded Docetaxel and the Generic Formulations.
Studies have raised concern about the safety of generic compared with branded drugs. Febrile neutropenia (FN) resulting in hospital admission was compared between the branded docetaxel (Taxotere®, Sanofi) and 2 generic formulations (docetaxel Ebewe and docetaxel Hospira) in patients with breast cancer. This was a retrospective study that included patients with breast cancer who received docetaxel between January 2012 and December 2014. ⋯ The overall incidence of FN resulting in hospital admission was significantly higher in patients who had received docetaxel Hospira, compared with patients who had received docetaxel Sanofi (47[5.8%] cycles vs 53 [3.5%] cycles, P = .009), but there was no significant difference between docetaxel Ebewe and docetaxel Sanofi (30[5.2%] cycles vs 53 [3.5%] cycles, P = .069). All cases of FN resolved except for 1 patient who died in the ICU after receiving docetaxel Ebewe. There was a significant difference in the incidence of FN between docetaxel Sanofi and docetaxel Hospira, but all cases in both groups resolved completely.
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Voriconazole, a broad-spectrum triazole antifungal agent, is metabolized by cytochrome P450 (CYP) 2C19 and, to a lesser extent, by CYP3A. Genetic polymorphism of CYP2C19 not only plays a prominent role in its disposition but may also influence potential drug interactions with CYP450 modulators such as ritonavir. This study assessed 2-way drug interactions of voriconazole added on to ritonavir-boosted atazanavir in both CYP2C19 extensive-metabolizer (EM) and poor-metabolizer (PM) healthy subjects. ⋯ The safety and tolerability profiles of the combination were comparable with atazanavir/ritonavir and voriconazole administered alone. The most frequent adverse events with voriconazole were visual disturbance and headache. Coadministration of voriconazole and atazanavir/ritonavir is not recommended unless the benefit/risk to the patient justifies the use of the combination.
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Palbociclib is an orally available CDK4/6 inhibitor. In humans, palbociclib undergoes metabolism mediated primarily by CYP3A and SULT2A1, and it is also a weak time-dependent CYP3A inhibitor. The objectives of the current study are to (1) develop a physiologically based pharmacokinetic (PBPK) model of palbociclib based on the in silico, in vitro, and in vivo pharmacokinetic data of palbociclib, (2) verify the PBPK model with clinical drug-drug interaction (DDI) results of palbociclib with strong CYP3A inhibitor (itraconazole), inducer (rifampin), and a sensitive CYP3A substrate (midazolam), and (3) predict the DDI risk of palbociclib with moderate/weak CYP3A inhibitors. ⋯ Using this final PBPK model, it was predicted that weak CYP3A inhibitors (fluoxetine and fluvoxamine) are anticipated to have negligible DDI risk with palbociclib, whereas moderate CYP3A inhibitors (diltiazem and verapamil) may increase plasma palbociclib AUC by ∼40%. A moderate CYP3A inducer (efavirenz) may decrease plasma palbociclib AUC by ∼40%. The established model is considered sufficiently robust for other applications in support of the continued development for palbociclib.