Absence of clinically relevant drug-drug interaction between odanacatib and digoxin after concomitant administration

Abstract Purpose Ceritinib is an ALK receptor tyrosine kinase inhibitor approved as first- and second-line treatment in adult patients with ALK + metastatic non-small cell lung cancer (NSCLC). The study investigated the drug–drug interaction (DDI) potential of ceritinib when coadministered with midazolam and warfarin as probe substrates for CYP3A and CYP2C9 activity, respectively. Methods This was a phase I, multicenter, open-label, single sequence, crossover DDI study in 33 adult patients with ALK + NSCLC or other advanced tumors. A single dose of a cocktail consisting of midazolam and warfarin was administered with and without concomitant administration of ceritinib. The primary objective was to evaluate the pharmacokinetics of midazolam and warfarin. Secondary objectives included pharmacokinetics, safety, tolerability, overall response rate (ORR), and duration of response (DOR) of ceritinib 750 mg once daily. Results Ceritinib inhibited CYP3A-mediated metabolism of midazolam, resulting in a markedly increased AUC (geometric mean ratio [90% confidence interval]) by 5.4-fold (4.6, 6.3). Ceritinib also led to an increase in the AUC of S-warfarin by 54% (36%, 75%). The pharmacokinetics and safety profile of ceritinib in this study are consistent with previous reports and no new safety signals were reported. Among the 19 patients with NSCLC, efficacy (ORR: 42.1% and DCR: 63.2%) was similar to that reported previously in studies of pretreated patients with ALK + NSCLC. Conclusion Ceritinib is a strong CYP3A inhibitor and a weak CYP2C9 inhibitor. These findings should be reflected as actionable clinical recommendations in the prescribing information for ceritinib with regards to concomitant medications whose pharmacokinetics may be altered by ceritinib.

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Drug–drug interaction between itraconazole capsule and efavirenz in adults with HIV for talaromycosis treatment

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa521 ◽

2020 ◽

Author(s):

Quanhathai Kaewpoowat ◽

Romanee Chaiwarith ◽

Saowaluck Yasri ◽

Navaporn Worasilchai ◽

Ariya Chindamporn ◽

...

Keyword(s):

Drug Interaction ◽

Geometric Mean ◽

Compartmental Analysis ◽

Concomitant Administration ◽

Open Label ◽

Capsule Formulation ◽

Post Dose ◽

Cd4 Cell Count ◽

Drug Drug Interaction ◽

Cd4 Cell

Abstract Objectives To assess the pharmacokinetic of itraconazole capsule formulation and its active metabolite, hydroxyitraconazole, in adults with HIV diagnosed with talaromycosis in an endemic area, and to evaluate the drug–drug interaction between itraconazole/hydroxyitraconazole (ITC/OH-ITC) and efavirenz. Methods Open-label, single arm, sequential pharmacokinetic study. Eligible subjects were adults with HIV, ≥18 years old, with confirmed talaromycosis, initiating itraconazole capsule as part of standard talaromycosis treatment, in whom efavirenz-based ART was anticipated. Steady-state pharmacokinetic assessments (pre-dose and at 1, 3, 4, 5, 6, 8 and 12 h post dose) were performed for itraconazole/hydroxyitraconazole without and with efavirenz use. Mid-dose efavirenz concentrations were also assessed. Pharmacokinetics parameters were calculated using non-compartmental analysis. Results Ten subjects (70% male) were enrolled. At entry, median (range) age was 29.5 years (22–64), and CD4 cell count was 18.0 (1–39) cells/mm3. Geometric mean (95% CI) of itraconazole and hydroxyitraconazole AUC0–12 without efavirenz were 9097 (6761–12 239) and 11 705 (8586-15 959) ng·h/mL, respectively, with a median metabolic ratio of OH-ITC : ITC of 1.3 (95% CI 0.9–1.9). Intra-subject comparison revealed that both itraconazole and hydroxyitraconazole exposures were significantly reduced with concomitant efavirenz use, with the mean AUC0–12 of itraconazole and hydroxyitraconazole being 86% (71%–94%) and 84% (64%–97%) lower, respectively. With efavirenz, itraconazole trough concentrations were also below the recommended therapeutic level (0.5 μg/mL). All subjects had mid-dose efavirenz concentrations >1000 ng/mL. Conclusions Concomitant administration of itraconazole capsule with efavirenz significantly reduced itraconazole and hydroxyitraconazole exposures. The clinical impact of this drug–drug interaction on talaromycosis treatment or prophylaxis in the era of potent ART needs further evaluation.

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Severe hypokalemia due to a possible drug–drug interaction between vinblastine and antiretrovirals in a HIV-infected patient with Hodgkin’s lymphoma

International Journal of STD & AIDS ◽

10.1177/0956462417703026 ◽

2017 ◽

Vol 28 (12) ◽

pp. 1259-1262 ◽

Cited By ~ 3

Author(s):

Ezequiel Cordova ◽

Laura Morganti ◽

Andrea Odzak ◽

Florencia Arcondo ◽

Mariana Silva ◽

...

Keyword(s):

Drug Interaction ◽

Renal Dysfunction ◽

Hodgkin’S Lymphoma ◽

Concomitant Administration ◽

Serum Levels ◽

Hodgkin's Lymphoma ◽

Tubular Damage ◽

Infected Woman ◽

Proximal Tubular ◽

Drug Drug Interaction

A 60-year-old HIV-1 infected woman on antiretroviral therapy (emtricitabine/tenofovir, and ritonavir-boosted atazanavir) developed Hodgkin’s lymphoma. The patient initiated ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) chemotherapy and presented with neutropenia and severe hypokalemia. Hypokalemia was considered as part of a proximal tubular renal dysfunction, and other causes of hypokalemia were excluded. Due to suspicion of drug-–drug interactions between antiretrovirals and vinblastine, ritonavir-boosted atazanavir was switched to dolutegravir and the patient continued emtricitabine/tenofovir. In the subsequent ABVD cycles, no neutropenia or hypokalemia were observed. Vinblastine is metabolized by the hepatic P450 cytochrome isoenzyme CYP3A4, therefore, concomitant administration with protease inhibitors may increase plasma levels of vinblastine. Vinblastine is also a substrate and inhibitor of multidrug resistance-associated protein 2 (MRP2) transporter in the proximal renal tubule. Inhibition of this renal transporter could increase tenofovir renal toxicity. Our hypothesis is that the hypokalemia could be a result of a tenofovir-mediated tubular damage triggered by the increased vinblastine serum levels secondary to a CYP3A4 inhibition by ritonavir. To the best of our knowledge, this is the first report of severe hypokalemia and proximal tubular renal dysfunction as a result of a possible drug–drug interaction between vinblastine, tenofovir and ritonavir-boosted atazanavir.

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Severe hyperkalaemia due to a potential drug–drug interaction between eplerenone and antiretrovirals in a HIV-positive patient after a myocardial infarction

International Journal of STD & AIDS ◽

10.1177/0956462420987422 ◽

2021 ◽

pp. 095646242098742

Author(s):

Ezequiel Cordova ◽

Franco Garibaldi ◽

Leandro Bono ◽

Claudia Rodriguez

Keyword(s):

Myocardial Infarction ◽

Drug Interaction ◽

Concomitant Administration ◽

Left Ventricular ◽

Medical Community ◽

Potential Drug ◽

Life Threatening ◽

Cyp3a4 Inhibitors ◽

Routine Laboratory Examination ◽

Drug Drug Interaction

We present a case of a 48-year-old white HIV-1 positive man who presented an acute myocardial infarction. The patient was on ART for the last ten years with emtricitabine/tenofovir and ritonavir-boosted fosamprenavir. Eplerenone 25 mg/day was also initiated due to a left ventricular dysfunction. A week after discharge a routine laboratory examination revealed severe hyperkalaemia. Due to suspicion of a potential drug–drug interaction, both eplerenone and ARVs were interrupted. Despite daily treatment for hyperkalaemia, serum potassium levels normalized after two weeks. Eplerenone is metabolized by the hepatic P450 cytochrome isoenzyme CYP3A4; therefore, concomitant administration with CYP3A4 inhibitors, like ritonavir, may increase plasma levels of eplerenone and, therefore, the risk of side effects, mainly hyperkalaemia. Based on this case, it is important to alert the medical community of this possible life-threatening drug-drug interaction between eplerenone and ritonavir-boosted protease inhibitor.

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