15433 Assessment of cytochrome P450 3A inhibition and induction of abrocitinib: Midazolam drug-drug interaction (DDI) study and oral contraceptive DDI study

We report a diagnosis of exogenous steroid-induced hypoadrenalism in a person living with HIV caused by a drug–drug interaction (DDI) between intrabursal triamcinolone and the pharmacokinetic booster cobicistat. A 53-year-old woman living with HIV, managed with dolutegravir and cobicistat-boosted darunavir, presented to the orthopaedic clinic with worsening hip pain. She was diagnosed with greater trochanteric pain syndrome (GTPS) of the hip and was treated with intrabursal injection of bupivacaine and triamcinolone. Seven days following this injection, she presented with Cushingoid features, an undetectable cortisol and was diagnosed with exogenous steroid-induced hypoadrenalism. Cobicistat is a cytochrome P450 3A inhibitor and in this case inhibited clearance of intrabursal triamcinolone, leading to exogenous glucocorticoid excess and adrenal suppression. This is the first report to describe this predictable DDI with cobicistat following intrabursal glucocorticoid injection. This case highlights the complexities in managing non-HIV-related chronic morbidities in people living with HIV.

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Physiologically‐Based Pharmacokinetic Modeling for the Prediction of a Drug–Drug Interaction of Combined Effects on P‐glycoprotein and Cytochrome P450 3A

CPT Pharmacometrics & Systems Pharmacology ◽

10.1002/psp4.12562 ◽

2020 ◽

Vol 9 (11) ◽

pp. 659-669

Author(s):

Yukio Otsuka ◽

Mary P. Choules ◽

Peter L. Bonate ◽

Kanji Komatsu

Keyword(s):

Cytochrome P450 ◽

Drug Interaction ◽

Pharmacokinetic Modeling ◽

Combined Effects ◽

Physiologically Based Pharmacokinetic Modeling ◽

Cytochrome P450 3A ◽

Physiologically Based Pharmacokinetic ◽

P Glycoprotein ◽

Physiologically Based ◽

Drug Drug Interaction

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In vitro study on the effect of cornin on the activity of cytochrome P450 enzymes

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-021-03309-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Qun Zhang ◽

Zengqiang Qu ◽

Yanqing Zhou ◽

Jin Zhou ◽

Junwei Yang ◽

...

Keyword(s):

Cytochrome P450 ◽

Drug Interaction ◽

Liver Microsomes ◽

In Vitro Study ◽

Inhibitory Effect ◽

Dependent Manner ◽

Cytochrome P450 Enzymes ◽

Drug Drug Interaction ◽

Dose Dependent

Abstract Background Cornin is a commonly used herb in cardiology for its cardioprotective effect. The effect of herbs on the activity of cytochrome P450 enzymes (CYP450s) can induce adverse drug-drug interaction even treatment failure. Therefore, it is necessary to investigate the effect of cornin on the activity of CYP450s, which can provide more guidance for the clinical application of cornin. Methods Cornin (100 μM) was incubated with eight isoforms of CYP450s, including CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6, and 2E1, in pooled human liver microsomes. The inhibition model and corresponding parameters were also investigated. Results Cornin exerted significant inhibitory effect on the activity of CYP3A4, 2C9, and 2E1 in a dose-dependent manner with the IC50 values of 9.20, 22.91, and 14.28 μM, respectively (p < 0.05). Cornin inhibited the activity of CYP3A4 non-competitively with the Ki value of 4.69 μM, while the inhibition of CYP2C9 and 2E1 by cornin was competitive with the Ki value of 11.31 and 6.54 μM, respectively. Additionally, the inhibition of CYP3A4 by cornin was found to be time-dependent with the KI/Kinact value of 6.40/0.055 min− 1·μM− 1. Conclusions The inhibitory effect of cornin on the activity of CYP3A4, 2C9, and 2E1 indicated the potential drug-drug interaction between cornin and drugs metabolized by these CYP450s, which needs further investigation and validation.

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