Drug-drug interactions with imatinib: An observational study

The prevalence of hepatic and thyroid toxicity associated with imatinib treatment of chronic myeloid leukaemia: a systematic review

BACKGROUND

Imatinib, a potent inhibitor of targeted protein tyrosine kinases, treats chronic myeloid leukaemia (CML). Data on imatinib-associated changes in hepatic and thyroid functions are limited and conflicting.

AIM

To report the prevalence of hepatic and thyroid toxicity associated with the use of imatinib in CML patients.

METHOD

Articles for the systematic review were selected from electronic databases (PubMed, CINALH, Web of Science). Readily accessible peer-reviewed full articles in English published 1st January 2000 to 18th July 2023 were included. The search terms included combinations of: imatinib, CML, liver toxicity, hepatic toxicity, thyroid toxicity. Screening of titles, abstracts, full text articles was conducted independently by two reviewers. Inclusions and exclusions were recorded following PRISMA guidelines. Detailed reasons for exclusion were recorded. Included articles were critically appraised.

RESULTS

Ten thousand one hundred and twenty-three CML patients were reported in the 82 included studies corresponding to 21 case reports, 2 case series, 39 clinical trials and 20 observational studies were selected. Excluding case studies/reports, 1268 (12.6%; n = 1268/10046) hepatotoxicity adverse events were reported, of which 64.7% were rated as mild grade I & II adverse events, 363 (28.6%) as severe, grade III and IV adverse events; some led to treatment discontinuation, liver transplantation and fatal consequences. Twenty (35.1%) studies reported discontinuation of imatinib treatment due to the severity of hepatic toxicity. Fourteen (8.4%, n = 14/167) thyroid dysfunction adverse events were reported.

CONCLUSION

High frequency of mild and severe hepatotoxicity, associated with imatinib in CML patients, was reported in the published literature. Low numbers of mild and manageable thyroid toxicity events were reported.

Drug-Drug Interactions Involving Dexamethasone in Clinical Practice: Myth or Reality?

Concomitant administration of multiple drugs frequently causes severe pharmacokinetic or pharmacodynamic drug-drug interactions (DDIs) resulting in the possibility of enhanced toxicity and/or treatment failure. The activity of cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp), a drug efflux pump sharing localization and substrate affinities with CYP3A4, is a critical determinant of drug clearance, interindividual variability in drug disposition and clinical efficacy, and appears to be involved in the mechanism of numerous clinically relevant DDIs, including those involving dexamethasone. The recent increase in the use of high doses of dexamethasone during the COVID-19 pandemic have emphasized the need for better knowledge of the clinical significance of drug-drug interactions involving dexamethasone in the clinical setting. We therefore aimed to review the already published evidence for various DDIs involving dexamethasone in vitro in cell culture systems and in vivo in animal models and humans.

Drug-drug interactions of protein kinase inhibitors in chronic myeloid leukaemia patients: A study using the French health insurance database

The introduction of protein kinase inhibitors (PKIs) for chronic myeloid leukaemia (CML) has considerably improved prognosis of the disease but has also demonstrated a great potential for drug-drug interactions. Using the French health insurance databases, we aim to investigate the frequency, identify the associated factors and describe the potential consequences of potential drug-drug interactions (pPKI-DIs) between PKIs and concurrent medications in CML. A retrospective cohort study has been performed among patients with CML identified in the French healthcare database from 2011 to 2014. A pPKI-DI is defined as the presence of drugs listed as 'interacting' on the same day as PKI dispensing (co-dispensing) or in its coverage period (co-medication) during the first year of follow-up. The list of interacting drugs is based on the summary of products characteristics (SPCs) and Thesaurus of interactions. We performed specific nested case-control comparisons to investigate the association between PKI-DI and each of the three potential outcomes (death, hospitalisation for adverse drug reactions and switch to another PKI). We included 3480 patients; 1429 (41%) had a co-dispensing pPKI-DI, and 2153 (62%) had a co-medication pPKI-DI; 50% of the pPKI-DIs were 'to be taken into account', and 17% were 'not recommended'. The PKI with the most interactions was imatinib, and additional common drug classes included statins, benzodiazepines and proton pump inhibitors. Multivariate analysis demonstrated that the use of a higher number of additional drugs, comorbidities at baseline, high number of prescribers and higher ages were potential risk factors. Nilotinib and dasatinib showed a tendency towards a higher risk of pPKI-DI compared to imatinib. Despite the fact that some PKI-DIs were potentially clinically relevant, we did not find any significant association with death, hospitalisation for adverse drug reactions and switching. These findings should increase awareness to help reduce the prevalence of PKI-drug interactions and thereby ensure better management of CML patients.

Management of chronic myelogenous leukemia with COVID-19 and hepatitis B

The application of immunosuppressive agents and targeted drugs has opened a novel approach for the treatment of hematological tumors, and the application of tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia is one of the landmark breakthroughs that has considerably improved the prognosis of CML patients. However, with the extensive use of TKI, the co-infection of CML patients has become increasingly apparent, especially regarding infectious diseases such as hepatitis B and COVID-19. The underlying mechanism may be related to the inhibition of the immune function by TKI. Poor management, including disease progression due to the infectious disease or TKI dose reduction or discontinuation, may lead to adverse clinical outcomes and can even be life-threatening. Therefore, this review principally provides an overview of the pathogenesis and standardized management principles of CML patients with comorbid COVID-19 or hepatitis B in order to improve clinicians' awareness of the risks so as to more effectively diagnose and treat CML and improve the survival rate and quality of life of patients. In the past two decades, owing to the advent of imatinib, chronic myeloid leukemia (CML) has transformed into a chronic controllable disease, and even treatment-free remission can be anticipated. Earlier studies have indicated that tyrosine kinase inhibitor (TKI) exerts a peculiar inhibitory effect on the body's immune function. Therefore, with the widespread application of TKI, more and more attention has been paid to the comorbidity of infectious diseases in CML patients, especially in patients with progressive disease or non-remission. Despite some studies revealing that the proportion and severity of SARS-CoV-2 infection in CML patients receiving TKI treatment are lower than in patients with other hematological malignancies, CML patients with stable disease are still recommended to be vaccinated against SARS-CoV-2, while TKI may or may not be discontinued. Meanwhile, the management of CML patients during the epidemic of coronavirus disease 2019 (COVID-19) still necessitates further discussion. This article also provides an overview of TKI-related hepatitis B reactivation. If not managed, patients may face adverse consequences such as hepatitis B reactivation-related hepatitis, liver failure, and progression of CML after forced withdrawal of medication. Therefore, this review aimed to comprehensively describe the management of CML patients with comorbid COVID-19, the pathogenesis of hepatitis B reactivation, the indicated population for prophylactic antiviral therapy, the time of antiviral drug discontinuation, and drug selection.

Involvement of the NF-κB and PI3K/Akt/mTOR pathways in cell death triggered by stypoldione, an o-quinone isolated from the brown algae Stypopodium zonale

Multiple myeloma (MM) is a clonal plasma cell malignancy that remains incurable to date. Thus, the aims of this study were to evaluate the involvement of the NF-κB and PI3K/Akt/mTOR pathways in the cytotoxicity of stypoldione, an o-quinone isolated from the brown algae Stypopodium zonale, in MM cells (MM1.S). The cytotoxic effect was evaluated in MM1.S cells and peripheral blood mononuclear cells (PBMCs) by MTT assay. The stypoldione reduced the cell viability of MM1.S cells in a concentration and time-dependent manner (IC50 in MM.1S from 2.55 to 5.38 μM). However, it was also cytotoxic to PBMCs, but at a lower range. Additionally, no significant hemolysis was observed even at concentration up to 10 times the IC50 . Apoptotic cell death was confirmed by cell morphology and Annexin V-FITC assay. Stypoldione induced intrinsic and extrinsic apoptosis by increasing FasR expression and reactive oxygen species (ROS) production, inverting the Bax/Bcl-2 ratio, and inducing ΔΨm loss, which resulted in AIF release and caspase-3 activation. It also increased Ki-67 and survivin expression and inhibited the NF-κB and PI3K/Akt/mTOR pathways. These results suggest that stypoldione is a good candidate for the development of new drugs for MM treatment.

An investigation of the use of app technology to support clinical management of patients with chronic myeloid leukaemia (CML)

Introduction

The availability of healthcare apps to support patient self-management of various medical conditions, including cancer, has increased considerably in the past decade. However, there are limited published data on the role of apps in the management of chronic myeloid leukaemia (CML). The primary aim of this study was to investigate the current and future role of apps as a means of supporting patients with CML.

Methods

A 31-item questionnaire was developed and distributed to patients via three on-line CML support groups.

Results

Responses were received from 286 patients. There was an approximate 2:1 female: male split and the majority (54%, n = 155) resided in the United Kingdom. 91% (n = 260) of respondents were currently receiving drug treatment for their CML. 23.4% (n = 67) of respondents were aware that apps were available to support their CML management and 11.5% (n = 33) had experience of using such an app. 94.1% (n = 238) of those who had not used a patient support app in the past stated that they would consider using an app in the future to help manage their disease. App awareness was significantly higher amongst male patients (30.3% vs. 19.9%). Likelihood of being a current or previous app user was higher amongst younger patients (16.3% for <55 years old vs. 5.6% for ≥55 years old) whilst younger patients and those with a more recent diagnosis of CML were both more likely to be interested in using an app in the future. When asked about potential app functionality, a drug interaction checker was the feature of greatest interest to respondents.

Conclusions

We have identified both a lack of awareness of and a low uptake of patient support apps amongst CML patients. Importantly, we have demonstrated a clear interest in CML-specific apps amongst this population. Based on the functionality that study participants were most interested in, we will work with health care professionals, app developers and patients to develop a new app to deliver holistic support to CML patients.

Patterns of Tyrosine Kinase Inhibitor Utilization in Newly Treated Patients With Chronic Myeloid Leukemia: An Exhaustive Population-Based Study in France

We analyzed demographic characteristics, comorbidities and patterns of treatment with tyrosine kinase inhibitors (TKIs) in a cohort of 3,633 incident cases of chronic myeloid leukemia (CML) identified across France from 1 January 2011 to 31 December 2014. Patients were identified through a specific algorithm in the French Healthcare Data System and were followed up 12 months after inclusion in the cohort. The estimated incidence rate of CML for this period in France was 1.37 per 100,000 person-years (95% Confidence Interval 1.36-1.38) and was higher in men, with a peak at age 75-79 years. At baseline, the median age of the cohort was 60 years (Inter Quartile Range 47-71), the Male/Female ratio was 1.2, and 25% presented with another comorbidity. Imatinib was the first-line TKI for 77.6% of the patients, followed by nilotinib (18.3%) and dasatinib (4.1%). Twelve months after initiation, 86% of the patients remained on the same TKI, 13% switched to another TKI and 1% received subsequently three different TKIs. During the follow-up, 23% discontinued and 52% suspended the TKI. Patients received a mean of 16.7 (Standard Deviation (SD) 9.6) medications over the first year of follow-up, and a mean of 2.7 (SD 2.3) concomitant medications on the day of first TKI prescription: 24.4% of the patients received allopurinol, 6.4% proton pump inhibitors (PPI) and 6.5% antihypertensive agents. When treatment with TKI was initiated, incident CML patients presented with comorbidities and polypharmacy, which merits attention because of the persistent use of these concomitant drugs and the potential increased risk of drug-drug interactions.

Potential drug interactions between targeted oral antineoplastic agents and concomitant medication in clinical practice

OBJECTIVES

Our objective was to analyze potential drug interactions (PDIs) between targeted OAAs and concomitant therapy in clinical practice.

METHODS

A cross-sectional observational study was performed in cancer outpatients who started treatment with a targeted OAA between 1 December 2015 and 31 May 2019. PDIs were analyzed using the Lexicomp® and the database About Herbs®. PDIs were classified according to severity, risk, and reliability ratings and their underlying mechanism. Univariate and multivariate analysis were performed to identify risk factors associated with PDIs.

RESULTS

A total of 881 patients were included, of whom 50.9% had at least 1 PDI between the OAA and the concomitant medication. The factors associated with a higher risk of PDIs were polypharmacy (≥5 concomitant medicines) (OR = 3.64 (2.54-5.20), p < 0.001), type of tumor (prostate cancer [OR = not available, p < 0.001], chronic myelogenous leukemia [OR = 5.10 (1.08-24.05), p = 0.040], sarcoma [OR = 4.97 (1.05-23.55), p = 0.043]), and treatment with hormone therapies (OR = not available, p < 0.001).

CONCLUSION

A search of PDIs should be prioritized, especially in patients receiving targeted OAAs with risk factors, such as polymedication, prostate cancer, chronic myelogenous leukemia, sarcoma, and treatment with hormone therapies.

Pharmacology for the Audiologist

The purpose of this article is to provide a brief introduction and review regarding basic principles of pharmacology, including terminology and colloquialisms, as well as pharmacokinetic and pharmacodynamic principles of ototoxic agents. As an audiology practitioner, it is more important than ever to have a working knowledge regarding the known and proposed mechanisms of action for drugs and chemicals with known ototoxicity potential. Additionally, this article provides a discussion regarding the biochemistry behind distribution, which is a major step in determining ototoxic potential of known and potential ototoxins.

Inadequate response to imatinib treatment in chronic myeloid leukemia due to a drug interaction with phenytoin

Imatinib mesylate and the newer BCR-ABL tyrosine kinase inhibitors are the standard therapy for chronic myeloid leukemia. Although these are remarkably effective drugs, some mechanisms of resistance have been identified including drug-to-drug interactions. Here we present the case of a chronic myeloid leukemia patient with an inadequate response to imatinib due to concurrent phenytoin administration. Conspicuously low imatinib plasma trough levels were documented. Imatinib dose was increased from 400 to 800 mg with good response. In conclusion, drug-to-drug interactions should be ruled out in cases of resistance to tyrosine kinase inhibitor treatment. Potent inducers of cytochrome P450 isoenzyme CYP3A4, as phenytoin, could induce inadequate responses due to increased imatinib clearance and low imatinib trough plasma levels. Thus, this interaction should be avoided. When this is not possible, dose escalation of imatinib and measurement of plasma levels, if available, is recommended.

Suppression of carboxylesterases by imatinib mediated by the down-regulation of pregnane X receptor

BACKGROUND AND PURPOSE

Imatinib mesylate (IM) is a first-line treatment for chronic myeloid leukaemia (CML) as a specific inhibitor of BCR-ABL tyrosine kinase. As IM is widely used in CML, in combination with other drugs, the effects of IM on drug-metabolizing enzymes (DMEs) are crucial to the design of rational drug administration. Carboxylesterases (CESs) are enzymes catalysing the hydrolytic biotransformation of several clinically useful drugs. Although IM is known to inhibit cytochromes P450 (CYPs), its effects on DMEs, and CESs in particular, are still largely undefined.

EXPERIMENTAL APPROACH

Hepatoma cell lines (HepG2 and Huh7) and primary mouse hepatocytes were used. mRNA and protein expression were evaluated by quantitative RT-PCR and Western blot analysis. Reporter luciferase activity was determined by transient co-transfection experiment. Pregnane X receptor (PXR) expression was regulated by overexpression and RNA interference. The activity of CESs was determined by enzymic and toxicological assays. Mice were treated with a range of doses of IM to analyse expression of CESs in mouse liver.

KEY RESULTS

The expression and activity of CESs were markedly repressed by IM, along with the down-regulation of PXR and inhibited expression and activity of CYP3A4 and P-gp.

CONCLUSIONS AND IMPLICATIONS

Down-regulation of PXR mediates IM-induced suppression of CESs. IM may inhibit expression of other genes targeted by PXR, thus inducing a wide range of potential drug-drug interactions during treatment of CML. The data deserve further elucidation including clinical trials.

Severe liver toxicity in a chronic myeloid leukemia patient probably induced by a drug interaction between imatinib and sertraline

Our objective is to describe a chronic myeloid leukemia patient with a severe liver toxicity likely due to a drug-drug interaction between imatinib and sertraline. The patient started treatment with sertraline three months after starting imatinib. From the beginning of sertraline treatment, the patient developed vomiting, and five weeks later she developed a severe hepatic failure and was admitted to the hospital. The Naranjo nomogram showed a probable correlation between this adverse effect and the interaction between imatinib and sertraline. This interaction is extremely rare and the mechanism of action is not clear; it could be a mix of pharmacokinetic and pharmacodynamic processes. To our knowledge, this is the first case in medical literature of a severe liver toxicity due to an interaction between imatinib and sertraline. This interaction is also not described in the main secondary data sources, such as Lexicomp® and Micromedex®. However, due to the severity of this event, the hepatic function should be carefully monitored in patients treated with imatinib and sertraline.