Fatal Statin-Induced Rhabdomyolysis by Possible Interaction with Palbociclib

Predicting drug-drug interactions in breast cancer patients treated with CDK4/6 inhibitors and forward planning

INTRODUCTION

Cyclin-dependent kinase (CDK) 4/6 inhibitors are cornerstones in the treatment of Hormone Receptor (HR) positive and Human Epidermal Growth factor (HER2) negative metastatic breast cancer. Given their widespread use in the metastatic setting and emerging use in the adjuvant setting, studying drug-drug interactions (DDI) of these medications is of utmost importance.

AREAS COVERED

This review provides key background information on the CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib. We discuss drug-drug interactions including those with proton pump inhibitors as well as CYP3A substrates, inhibitors, and inducers. We describe the effect of these drugs on membrane transporters and their substrates as well as those drugs that increase risk of CDK4/6 toxicities. Finally, we explore future directions for strategies to minimize drug-drug interactions.

EXPERT OPINION

It is crucial to be mindful of medications that may interfere with drug absorption, such as proton pump inhibitors, as well as those that interfere with drug metabolism, such as CYP3A4 inhibitors and inducers. Additionally, special consideration should be given to populations at higher risk for polypharmacy, such as older patients with greater comorbidities. These interactions and patient characteristics should be considered when developing individual treatment plans with CDK4/6 inhibitors.

CDK4/6 inhibitors in the treatment of metastatic breast cancer: Focus on toxicity and safety

The development of oral cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors, including palbociclib, ribociclib, and abemaciclib, has revolutionized the treatment landscape for patients with hormone-receptor-positive (HR+) and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (BC). When combined with an aromatase inhibitor or fulvestrant, these agents have been approved as first-line therapy in the metastatic setting. Abemaciclib has also gained FDA approval for patients with HR-positive, HER2-negative, node-positive, early BC at high risk of recurrence. Moreover, ribociclib has recently improved disease-free survival in patients with stage II or III HR+/HER2-negative early BC. CDK4/6 inhibitors have favorable safety profiles. However, the available agents have different toxicity profiles that must be clearly discussed with the patients for optimal clinical decisions. This manuscript aims to review CDK4/6 inhibitor-related treatment-associated adverse events, identify risk factors for intolerable adverse events, and assess their safety in special patient populations such as the elderly and those with renal insufficiency. Enhanced knowledge and understanding of CDK4/6 inhibitor-related toxicities can improve treatment strategies and ultimately enhance patient care.

Ribociclib may potentiate rosuvastatin effect in causing late onset rhabdomyolysis

A woman in her 50s with metastatic hormone receptor positive breast cancer developed rhabdomyolysis and subsequent acute kidney injury while on a combination of ribociclib and rosuvastatin therapy. She had been taking both medications long term and had recently recommenced her ribociclib at her usual dose after a routine 1 week break. Cyclin-dependent kinase 4/6 inhibitors have been implicated in causing rhabdomyolysis by potentiating statin effect by way of inhibition of cytochrome P450 enzymatic action and decreasing hepatic membrane transporter function. This is the first case in which the combination of ribociclib and rosuvastatin has been shown to cause this adverse effect. It is also one of the first to demonstrate this effect occurring years after commencement of therapy. Continued vigilance for this side effect should be maintained long term.

Differences in metabolic transport and resistance mechanisms of Abemaciclib, Palbociclib, and Ribociclib

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) play a crucial role in cancer treatment, particularly in breast cancer, and their mechanism of drug resistance is a topic of global interest in research. Hence, it is vital to comprehend the distinctions between various CDK4/6i, including their mechanisms of action and resistance mechanisms. This article aims to summarize the metabolic and transport variations as well as the differences in resistance among the three FDA-approved CDK4/6 inhibitors: Abemaciclib, Palbociclib, and Ribociclib. It also aims to discuss how these differences impact the effectiveness and safety of anticancer drugs. It was conducted in March 2023 to search PubMed, Embase, and Web of Science for literature related to this topic. Despite all being CDK4/6i, differences in their metabolism and transport were found, which are related to their chemical structure. Moreover, there are variations in preclinical pharmacology, pharmacokinetics, and clinical safety and efficacy of the different inhibitors. Genetic mutations, drug tolerance, and other factors may influence CDK4/6 resistance mechanisms. Currently, the resistance mechanisms differences of the three drugs remain largely unknown, and there are differences in the resistance mechanisms among them, necessitating further exploration and research.

Rhabdomyolysis Induced by the Interaction Between Ribociclib and Statins- Case Report and Literature Review

Cyclin-dependent kinase (CDK) 4/6 inhibitors given with endocrine therapy are standard of care for the treatment of women with advanced hormone receptor (HR) positive and human epidermal growth factor receptor 2 (HER-2) negative breast cancer. Ribociclib is a CDK 4/6 inhibitor with moderate to solid inhibition of CYP3A4, a member of the cytochrome P450 family oxidase system, which may lead to interactions with medicinal substrates that are metabolized via CYP3A4. Statins are among the most widely prescribed medications worldwide, predominantly metabolized by the CYP3A4 isoenzyme. Rhabdomyolysis is a known rare side effect of statins, commonly triggered by drug interactions. We report a case of a 73-year-old woman with metastatic HR-positive and HER-2 negative breast cancer who developed rhabdomyolysis and acute kidney injury due to interaction between simvastatin and ribociclib with a literature review.

Severe toxic rhabdomyolysis under combined palbociclib and simvastatin treatment: A case report

We report the fourth described case of severe toxic rhabdomyolysis occurring in an 81-year-old woman caused by the concomitant administration of palbociclib taken at the usual dosage (125 mg per day) and simvastatin. To the best of our knowledge, this is the first reported case successfully treated by plasma exchanges, with complete functional recovery within two months. The severity of this case justifies further consideration of pharmacokinetic interactions between palbociclib or other CDK-4-6 inhibitors and statins, which potentially increase the risk of an adverse event.

Fentanyl versus Methadone in Management of Withdrawal Syndrome in Opioid Addicted Patients; a Pilot Clinical Trial

Introduction:

The most effective treatment for withdrawal syndrome in Opioid-dependent patients admitted to intensive care units (ICUs) remains unknown. This study aimed to compare fentanyl and methadone in this regard.

Methods:

This prospective, single-blinded, controlled pilot study was conducted on opioid-dependent intubated patients admitted to the toxicology ICU of Loghman Hakim Hospital, Tehran, Iran, between August 2019 and August 2020. Patients were alternately assigned to either fentanyl or methadone group after the initiation of their withdrawal syndrome. Duration and alleviation of the withdrawal signs and symptoms, ICU and hospital stay, development of complications, development of later signs/symptoms of withdrawal syndrome, and need for further administration of sedatives to treat agitation were then compared between these two groups.

Results:

Median age of the patients was 42 [interquartile range (IQR): 26, 56]. The two groups were similar in terms of the patients’ age (p = 0.92), sex (p = 0.632), primary Simplified Acute Physiology Score (SAPS) II (p = 0.861), and Clinical Opiate Withdrawal Score (COWS) before (p = 0.537) and 120 minutes after treatment (p = 0.136) with either methadone or fentanyl. The duration of intubation (p = 0.120), and ICU stay (p = 0.572), were also similar between the two groups. The only factor that was significantly different between the two groups was the time needed for alleviation of the withdrawal signs and symptoms after the administration of the medication, which was significantly shorter in the methadone group (30 vs. 120 minutes, p = 0.007).

Conclusion:

It seems that methadone treats the withdrawal signs and symptoms faster in dependent patients. However, these drugs are similarly powerful in controlling the withdrawal signs in these patients.

The Value of Lactate Dehydrogenase in Predicting Rhabdomyolysis-Induced Acute Renal Failure; a Narrative Review

Introduction

Determining the diagnostic value of available biomarkers in predicting rhabdomyolysis-induced acute kidney injury (AKI) is a priority. This study aimed to review the current evidence about the value of lactate dehydrogenase (LDH) in this regard.

Methods

In this narrative review, the papers in PubMed, Embase, and web of science were studied. The keywords prognosis, prognoses, prognostic, LDH, rhabdomyolysis, emergency patients, and acute kidney failure or AKI had been selected from MeSH medical dictionary. Related papers written in English and published from November 2007 to December 2020 were selected.

Results

Finally, 14 articles were accepted for analysis. Among the selected articles, four were randomized clinical trials, seven were cross-sectional, and three were case-control studies. The results of the present review showed that abuse of illegal drugs is the most common cause of rhabdomyolysis. AKI is the most serious complication of rhabdomyolysis reported in the studies. These studies have shown a three-fold increase in AKI following drug-induced rhabdomyolysis. The review of the included articles shows that high LDH can predicts AKI, especially in critical and emergency situations such as rhabdomyolysis where there is a risk of death if diagnosed late. These studies show that LDH increases in the presence of renal failure and tissue damage.

Conclusion

Serum LDH is an appropriate and cost-effective prognostic indicator that can be used for risk classification of patients at risk for rhabdomyolysis-induced AKI.

Severe rhabdomyolysis induced by possible drug-drug interaction between Ribociclib and Simvastatin

INTRODUCTION

Drug-drug interactions with cyclin-dependent kinases inhibitors 4 and 6 (CDK4/6) are known and should be taken into account.

CASE REPORT

A 68-year-old woman, on prior Simvastatin therapy, developed severe rhabdomyolysis after three weeks of Ribociclib initiation. She showed general weakness with mobility problems and was admitted to our hospital.

MANAGEMENT AND OUTCOME

Ribociclib and Simvastatin were discontinued and the patient received intensive intravenous hydration. She finally recovered her mobility after two weeks.

DISCUSSION

We hypothesize that Simvastatin induced rhabdomyolysis by possible interaction with Ribociclib. Ribociclib is a strong inhibitor of CYP 3A4 and a potential inhibitor of OATP1B1 membrane transporter. Simvastatin plasma concentration may reach toxic levels due to Ribociclib inhibition. To assess the relevance of our hypothesis, we used the Drug Interaction Scale. With a total score of 7, the interaction is considered as "probable." Because of the high risk of severe rhabdomyolysis, the concomitant use of Simvastatin with Ribociclib should be avoided or otherwise careful monitoring of creatine kinase is warranted.

Palbociclib in combination with simvastatin induce severe rhabdomyolysis: a case report

Background

Palbociclib is a selective well-tolerated antineoplastic drug used in the treatment of advanced HER2-negative, estrogen-receptor positive breast cancer that has shown significant improvement in progression-free survival. We present a patient that developed severe rhabdomyolysis with tetra-affection and loss of gait after initiating the first cycle of Palbociclib concomitantly with Simvastatin 40 mg treatment.

Case presentation

A 71-year-old woman with metastatic breast cancer developed tetraparesis and near fatal rhabdomyolysis after initiation of first cycle Palbociclib. For 10 years prior to this treatment, the patient had been treated with Simvastatin without myalgia or other neuromuscular complaints prior to the first cycle of Palbociclib. The patient was admitted at the neurology department, where Palbociclib and Simvastatin were discontinued. The patient was aggressively hydrated and treated with intravenous immunoglobulin therapy with slowly remission and finally regaining independent gait function. Evaluation showed a negative myositis antibody work-up. Muscle magnetic resonance imaging showed edema in multiple foci, but skeletal muscle biopsy did not show necrosis. Post discharge genetic analysis showed single heterozygosity for nucleotide polymorphism rs4149056.

Conclusion

We present a patient who developed severe rhabdomyolysis induced by a combination of Palbociclib and Simvastatin treatment. Rhabdomyolysis was most likely induced by toxic plasma concentrations of Simvastatin due to Palbociclibs inhibition of the CYP3A4 enzyme in combination with a decreased hepatic uptake of Simvastatin due to single nucleotide polymorphism rs4149056. The study underscores that combining Simvastatin and Palbociclib should be done cautiously and genetic testing of the rs4149056 SNP is warranted. If present, Simvastatin should be discontinued or replaced with a lesser myopathic statin in regard to patients risk of cardiovascular events.

Prediction of pharmacokinetic drug-drug interactions causing atorvastatin-induced rhabdomyolysis using physiologically based pharmacokinetic modelling

Atorvastatin and its lactone form metabolite are reported to be associated with statin-induced myopathy (SIM) such as myalgia and life-threatening rhabdomyolysis. Though the statin-induced rhabdomyolysis is not common during statin therapy, its incidence will significantly increase due to pharmacokinetic drug-drug interactions (DDIs) with inhibitor drugs which inhibit atorvastatin's and its lactone's metabolism and hepatic uptake. Thus, the quantitative analysis of DDIs of atorvastatin and its lactone with cytochrome P450 3A4 (CYP3A4) and organic anion-transporting polypeptide (OATP) inhibitors is of great importance. This study aimed to predict pharmacokinetic DDIs possibly causing atorvastatin-induced rhabdomyolysis using Physiologically Based Pharmacokinetic (PBPK) Modelling. Firstly, we refined the PBPK models of atorvastatin and atorvastatin lactone for predicting the DDIs with CYP3A4 and OATP inhibitors. Thereafter, we predicted the exposure changes of atorvastatin and atorvastatin lactone originating from the case reports of atorvastatin-induced rhabdomyolysis using the refined models. The simulation results show that pharmacokinetic DDIs of atorvastatin and its lactone with fluconazole, palbociclib diltiazem and cyclosporine are significant. Consequently, clinicians should be aware of necessary dose adjustment of atorvastatin being used with these four inhibitor drugs.

Management of Adverse Events Due to Cyclin-Dependent Kinase 4/6 Inhibitors

Cyclin-dependent kinase (CDK) 4/6 inhibitors have become standard of care in the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer. They have been shown to double the efficacy of endocrine-based treatment. Three oral agents are available to date: palbociclib, ribociclib, and abemaciclib. The aim of this article is to give a short overview of the existing efficacy data, to summarize the recommended clinical monitoring procedures for patients under CDK4/6 inhibitors, and to shed light on the clinical management of the most common treatment-emergent adverse events. The hematological class side effect neutropenia as well as non-hematological toxicities (e.g., impaired liver function, prolonged QTc interval, and diarrhea) are discussed. In addition, the current knowledge about relevant drug interactions is reviewed.

Familial Hypercholesterolemia: New Horizons for Diagnosis and Effective Management

Familial hypercholesterolemia (FH) is a common genetic cause of premature cardiovascular disease (CVD). The reported prevalence rates for both heterozygous FH (HeFH) and homozygous FH (HoFH) vary significantly, and this can be attributed, at least in part, to the variable diagnostic criteria used across different populations. Due to lack of consistent data, new global registries and unified guidelines are being formed, which are expected to advance current knowledge and improve the care of FH patients. This review presents a comprehensive overview of the pathophysiology, epidemiology, manifestations, and pharmacological treatment of FH, whilst summarizing the up-to-date relevant recommendations and guidelines. Ongoing research in FH seems promising and novel therapies are expected to be introduced in clinical practice in order to compliment or even substitute current treatment options, aiming for better lipid-lowering effects, fewer side effects, and improved clinical outcomes.

An update on efflux and uptake transporters as determinants of statin response

INTRODUCTION

Statins are used in the treatment of dyslipidemia promoting primary and secondary prevention against detrimental cardiovascular events. ATP-binding cassette (ABC) and solute carrier (SLC) membrane transporters transport statins across the cell membrane. Differences in drug transporter tissue expression and activity contribute to variability in statin pharmacokinetics (PK) and response. Areas covered: The purpose of this review is to discuss factors impacting transporter expression and the effect this has on statin efficacy and safety. Previous studies have demonstrated that genetic polymorphisms, drug-drug interactions (DDI), nuclear receptors, and microRNAs affect statin PK and pharmacodynamics. Expert opinion: Genetic variants of ABCG2 and SLCO1B1 transporters affect statin PK and, as a result, the intended lipid-lowering response. However, the effect size is small, limiting its applicability in clinical practice. Furthermore, genetic variants do not totally explain the observed intervariability in statin response. Thus, it is likely that transcriptional and post-transcriptional regulation of drug transporters are also highly involved. Further studies are required to understand the contribution of each of these new factors in statin disposition and toxicity.