Drug-Induced Arrhythmias: A Scientific Statement From the American Heart Association

Many widely used medications may cause or exacerbate a variety of arrhythmias. Numerous antiarrhythmic agents, antimicrobial drugs, psychotropic medications, and methadone, as well as a growing list of drugs from other therapeutic classes (neurological drugs, anticancer agents, and many others), can prolong the QT interval and provoke torsades de pointes. Perhaps less familiar to clinicians is the fact that drugs can also trigger other arrhythmias, including bradyarrhythmias, atrial fibrillation/atrial flutter, atrial tachycardia, atrioventricular nodal reentrant tachycardia, monomorphic ventricular tachycardia, and Brugada syndrome. Some drug-induced arrhythmias (bradyarrhythmias, atrial tachycardia, atrioventricular node reentrant tachycardia) are significant predominantly because of their symptoms; others (monomorphic ventricular tachycardia, Brugada syndrome, torsades de pointes) may result in serious consequences, including sudden cardiac death. Mechanisms of arrhythmias are well known for some medications but, in other instances, remain poorly understood. For some drug-induced arrhythmias, particularly torsades de pointes, risk factors are well defined. Modification of risk factors, when possible, is important for prevention and risk reduction. In patients with nonmodifiable risk factors who require a potentially arrhythmia-inducing drug, enhanced electrocardiographic and other monitoring strategies may be beneficial for early detection and treatment. Management of drug-induced arrhythmias includes discontinuation of the offending medication and following treatment guidelines for the specific arrhythmia. In overdose situations, targeted detoxification strategies may be needed. Awareness of drugs that may cause arrhythmias and knowledge of distinct arrhythmias that may be drug-induced are essential for clinicians. Consideration of the possibility that a patient's arrythmia could be drug-induced is important.

Combination therapy of ipilimumab and nivolumab induced thyroid storm in a patient with Hashimoto's disease and diabetes mellitus: a case report

BACKGROUND

Recently, immune checkpoint inhibitors have widely been used for the management of advanced melanoma. However, high-grade immune-related adverse events can occur, particularly with combination immunotherapy. We report a case of a patient with melanoma who developed thyroid storm following treatment with ipilimumab and nivolumab.

CASE PRESENTATION

An 85-year-old Japanese man with a history of malignant melanoma presented to our department with severe thyrotoxicosis and poor blood glucose control. He was already being treated for Hashimoto's disease and type 2 diabetes mellitus before the treatment for the melanoma. During admission, laboratory investigations revealed the following thyroid functions: thyroid-stimulating hormone below sensitivity, free triiodothyronine 31.7 pg/ml, and thyroglobulin 48,000 IU/ml. Thyroid-stimulating hormone receptor antibody was negative, and a ^99mTc-labeled thyroid scan revealed a markedly decreased uptake. He was treated with beta-blocker, orally administered potassium iodine, a relatively low dose of prednisolone, and insulin injection therapy to control his blood glucose, resulting in an improvement in thyroid function and his symptoms.

CONCLUSION

It might be important to be aware of the possibility of thyroid storm induced by immune checkpoint inhibitors.

Predictive features associated with thyrotoxic storm and management

Thyroid storm (TS) is an endocrine emergency characterized by rapid deterioration, associated with high mortality rate therefore rapid diagnosis and emergent treatment is mandatory. In the past, thyroid surgery was the most common cause of TS, but recent preoperative medication creates a euthyroid state before performing surgery. An active approach during perioperative period could determine an effective clinical treatment of this life-threating diseases. Recently, the Japan Thyroid Association and Japan Endocrine Society developed diagnostic criteria for TS focusing on premature and prompt diagnosis avoiding inopportune e useless drugs. This review analyses predictive features associated with thyrotoxic storm highlighting recent literature to optimize the patient quality of care.

Sorafenib-Induced Changes in Thyroid Hormone Levels in Patients Treated for Hepatocellular Carcinoma

CONTEXT

The pathogenesis of tyrosine kinase inhibitor-induced thyroid hormone (TH) alterations are still a matter of debate.

OBJECTIVE

The objective of this study was to determine the effects of sorafenib on TH levels in patients with hepatocellular carcinoma (HCC) and to evaluate possible mechanisms.

DESIGN

We performed a prospective cohort study between 2009 and 2016.

SETTING

This study was conducted at a tertiary referral center.

PATIENTS

This study included 57 consecutive patients with HCC who were treated with sorafenib.

MAIN OUTCOME MEASURE

Thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels were measured every 6 weeks, and extensive thyroid function tests (TFTs) were measured before treatment (t0), after 6 weeks (t6), and at the end of therapy. The effect of sorafenib on TH transport by monocarboxylate transporter (MCT)8 or MCT10 was tested in transfected COS1 cells.

RESULTS

Four patients (7%) developed thyroiditis. Among the other patients, 30% had elevation of TSH or FT4 above the normal range. Overall, between t0 and t6, mean TSH increased from 1.28 to 1.57 mU/L (P < 0.001) and mean FT4 from 18.4 to 21.2 pmol/L (P < 0.001). Simultaneously, the serum triiodothyronine (T3)/reverse triiodothyronine ratio and the (T3/thyroxine) ×100 ratio decreased. Sorafenib decreased cellular T3 uptake by MCT8 and to a lesser extent by MCT10.

CONCLUSIONS

These in vivo data suggest that sorafenib affects TFTs on multiple levels. Our in vitro experiments suggest a possible role of sorafenib-induced inhibition of T3 transport into the cell by MCT8 and MCT10.

Case of pazopanib-induced thyrotoxicosis in a patient with metastatic renal cell carcinoma

Pazopanib is an oral multi-targeted tyrosine kinase inhibitor and has been approved for metastatic renal cell carcinoma and advanced soft tissue sarcoma. To the best of our knowledge, pazopanib-induced thyrotoxicosis has never been reported. The patient was a 68-year-old woman with renal cell carcinoma and multiple metastases. Three weeks after pazopanib medication, she felt fatigue and palpitation. She was admitted because of liver chemistry abnormalities [AST 723 IU/L (normal range 7-37 IU/L); ALT 953 IU/L (normal range 3-33 IU/L)]. She showed abnormal thyroid function tests with suppressed TSH of 0.0585 μIU/mL, and elevated fT4 of 3.38 ng/dL. Ten days after admission, tachycardia appeared and fT3 and fT4 were elevated (fT3 27.85 pg/mL, fT4 2.58 ng/dL), and TSH was suppressed (0.0414 μIU/mL). Her thyroid ultrasound showed hypervascular thyroid gland without nodules. We diagnosed pazopanib-induced thyrotoxicosis. Because the fT3/fT4 ratio was high (10.8) and the thyroid was enlarged, we thought that her thyrotoxicosis might get worse. She was treated with medication of beta-blockers, hydrocortisone, and potassium iodide and thyrotoxicosis resolved. This report highlights that Pazopanib could induce thyrotoxicosis, and therefore, periodic surveillance of thyroid function is required during pazopanib therapy.

Managing tyrosine kinase inhibitors side effects in thyroid cancer

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are a new group of drugs that show the activity against receptors of different growth factors leading to the inhibition of tumor cells growth and proliferation. To date, four different TKIs have been approved for RAI-refractory DTC or MTC: sorafenib, lenvatinib, vandetanib and cabozantinib.

METHODS

This review focuses on treatment toxicity related to above-mentioned TKIs administration in thyroid carcinoma.

RESULTS

TKIs cause a variety of side effects in nearly all treated patients, among them: hypertension, gastrointestinal disturbances (diarrhea, abdominal pain, nausea, vomiting), skin reactions (rashes, acne, hand-foot syndrome), fatigue and weight loss. Most of side effects are mild and moderate and manageable by dose adjustment (dose interruptions and dose reductions) and concomitant therapy. However, some complications although rare may be life-threatening or even fatal. Conclusion​: TKIs shows an acceptable toxicity profile in patients with advanced and progressive RAI refractory DTC and MTC but only in experienced hands familiar with TKIs, particularly with diagnostics and management of treatment-related complications and also with thyroid carcinoma, what is essential to safely care for the patients and keep them on kinase inhibitor therapy as long as the treatment is beneficial without an unfavorable impact on their quality of life.

2016 Guidelines for the management of thyroid storm from The Japan Thyroid Association and Japan Endocrine Society (First edition)

Thyroid storm is an endocrine emergency which is characterized by multiple organ failure due to severe thyrotoxicosis, often associated with triggering illnesses. Early suspicion, prompt diagnosis and intensive treatment will improve survival in thyroid storm patients. Because of its rarity and high mortality, prospective intervention studies for the treatment of thyroid storm are difficult to carry out. We, the Japan Thyroid Association and Japan Endocrine Society taskforce committee, previously developed new diagnostic criteria and conducted nationwide surveys for thyroid storm in Japan. Detailed analyses of clinical data from 356 patients revealed that the mortality in Japan was still high (∼11%) and that multiple organ failure and acute heart failure were common causes of death. In addition, multimodal treatment with antithyroid drugs, inorganic iodide, corticosteroids and beta-adrenergic antagonists has been suggested to improve mortality of these patients. Based on the evidence obtained by nationwide surveys and additional literature searches, we herein established clinical guidelines for the management of thyroid storm. The present guideline includes 15 recommendations for the treatment of thyrotoxicosis and organ failure in the central nervous system, cardiovascular system, and hepato-gastrointestinal tract, admission criteria for the intensive care unit, and prognostic evaluation. We also proposed preventive approaches to thyroid storm, roles of definitive therapy, and future prospective trial plans for the treatment of thyroid storm. We hope that this guideline will be useful for many physicians all over the world as well as in Japan in the management of thyroid storm and the improvement of its outcome.

A case report: delayed high fever and maculopapules during Sorafenib treatment of ectopic hepatocellular carcinoma

Background

Sorafenib is the standard first-line therapy for hepatocellular carcinoma (HCC) and probably ectopic hepatocellular carcinoma (EHCC) as well. No report involves a side effect of delayed high fever of sorafenib. This manuscript describes a case of EHCC in the thoracic and abdominal cavities, who showed a delayed high fever and maculopapules during sorafenib treatment.

Case presentation

The patient is a 63-year-old Chinese male with advanced EHCC, taking sorafenib 400 mg twice daily. On the tenth day, red maculopapules appeared all over the body. On the same day, the patient began to suffer from continuous high fever. Due to these effects, the patient was asked to cease sorafenib treatment, and the high fever and maculopapules were alleviated quickly. However, the symptoms were present again upon re-challenge of sorafenib. Prednisone was then administered to control the symptoms, with the dosage gradually reduced from 30 to 5 mg/day in 1.5 months. No recurrence of fever or maculopapules has been found. Tumor response reached partial response (PR) and progression free survival (PFS) reached 392 days + by the date of Apr. 14th, 2016.

Conclusion

EHCC could be treated like orthotopic HCC by oral administration of sorafenib, which shows good tumor response and survival benefit. Delayed high fever and maculopapules are potential, rare and severe side effects of sorafenib, and could be effectively controlled by glucocorticoid.

Endocrine side-effects of anti-cancer drugs: thyroid effects of tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs) are currently used by most oncologists. Among their side effects, thyroid dysfunctions are nowadays clearly observed. Whereas changes in thyroid function tests have been originally described with sunitinib, we now know that many TKIs can induce hypothyroidism and hyperthyroidism. In this study, the various molecules implicated in thyroid dysfunctions are analysed and the latest data on physiopathological mechanisms are approached in order to propose a strategy of thyroid monitoring of patients on TKI therapy.

Thyroid dysfunctions induced by tyrosine kinase inhibitors

INTRODUCTION

Recently, tyrosine kinase inhibitors (TKIs) have emerged as a new class of anticancer therapy. Although generally considered less toxic than cytotoxic chemotherapy, TKIs do cause significant side effects including fatigue and hypertension. In addition, thyroid dysfunction is a well-known adverse effect of TKI.

AREAS COVERED

This review provides a comprehensive assessment of TKI-induced thyroid dysfunctions by sunitinib, sorafenib, pazopanib, imatinib, dasatinib, nilotinib, vandetanib, axitinib, motesanib and tivozanib. Furthermore, the potential mechanisms that result in this toxicity, the clinical impact of thyroid dysfunction in these patients and the controversies regarding treatment with thyroid hormone (TH) therapy are evaluated.

EXPERT OPINION

Detection of TKI-induced thyroid dysfunction requires routine monitoring of thyroid function and may necessitate treatment. Potential benefits in developing thyroid dysfunction and potential harm in treating it necessitate controlled studies. Finally, if treatment is pursued, appropriate dosing and timing of TH replacement will require prospective clinical evaluation.

Clinical concepts on thyroid emergencies

OBJECTIVE

Thyroid-related emergencies are caused by overt dysfunction of the gland which are so severe that require admission to intensive care units (ICU) frequently. Nonetheless, in the ICU setting, it is crucial to differentiate patients with non-thyroidal illness and alterations in thyroid function tests from those with intrinsic thyroid disease. This review presents and discusses the main etiopathogenetical and clinical aspects of hypothyroid coma (HC) and thyrotoxic storm (TS), including therapeutic strategy flow-charts. Furthermore, a special chapter is dedicated to the approach to massive goiter, which represents a surgical thyroid emergency.

DATA SOURCE

We searched the electronic MEDLINE database on September 2013. Data Selection and Data Extraction: Reviews, original articles, and case reports on "myxedematous coma," "HC," "thyroid storm," "TS," "massive goiter," "huge goiter," "prevalence," "etiology," "diagnosis," "therapy," and "prognosis" were selected.

DATA SYNTHESIS AND CONCLUSION

Severe excess or defect of thyroid hormone is rare conditions, which jeopardize the life of patients in most cases. Both HC and TS are triggered by precipitating factors, which occur in patients with severe hypothyroidism or thyrotoxicosis, respectively. The pillars of HC therapy are high-dose l-thyroxine and/or tri-iodothyroinine; i.v. glucocorticoids; treatment of hydro-electrolyte imbalance (mainly, hyponatraemia); treatment of hypothermia; often, endotracheal intubation and assisted mechanic ventilation are needed. Therapy of TS is based on beta-blockers, thyrostatics, and i.v. glucocorticoids; eventually, high-dose of iodide compounds or lithium carbonate may be of benefit. Surgery represents the gold standard treatment in patients with euthyroid massive nodular goiter, although new techniques - e.g., percutaneous laser ablation - are helpful in subjects at high surgical risk or refusing operation.