In case of anastrozole-related hallucinations, can switching to letrozole be a treatment option? A case report and literature review

Ribociclib-induced visual hallucination in a patient with metastatic breast cancer

INTRODUCTION

Cyclin-dependent kinase (CDK) 4/6 inhibitors are widely used in combination with aromatase inhibitors or fulvestrant for the treatment of locally advanced or metastatic hormone receptor-positive (HR+), human epidermal growth factor 2-negative (HER2-) breast cancer. Hematological toxicities (e.g. neutropenia, thrombocytopenia, anemia, lymphopenia, or febrile neutropenia), infections, decreased appetite, exhaustion, headache, dizziness, cough, nausea, vomiting, diarrhea, alopecia, rash, increased alanine aminotransferase and aspartate aminotransferase levels, and QT interval prolongation are frequent side effects associated with the use of CDK 4/6 inhibitors. However, to our knowledge, no case of hallucination associated with CDK 4/6 inhibitor use has been described in the English-language literature.

CASE REPORT

We report a case of a 72-year-old woman with metastatic breast cancer who developed visual hallucinations after receiving ribociclib, a CDK 4/6 inhibitor, and letrozole for 3 days. Cranial imaging and blood tests did not reveal the cause of the hallucinations.

MANAGEMENT AND OUTCOME

The visual hallucinations completely resolved within 4 days after the ribociclib treatment was terminated. The patient received only letrozole for 2 weeks, and ribociclib treatment was restarted 2 weeks later. Visual hallucinations recurred on the third day of treatment, and ribociclib treatment was discontinued again. The patient recovered completely from visual hallucinations 4 days after discontinuation. Subsequently, treatment was continued with letrozole and palbociclib, another CDK 4/6 inhibitor. Hallucinations did not recur during follow-up.

DISCUSSION

To our knowledge, this is the first reported case of hallucinations caused by ribociclib; notably, it shows that symptoms may develop in the early stage of treatment.

New-onset hallucinations with amiodarone: a case report

BACKGROUND

Amiodarone is a commonly used antiarrhythmic for the treatment of atrial fibrillation with a unique pharmacokinetic profile. While general side effects can be frequently associated with amiodarone, psychiatric adverse reactions to this medication are uncommon. The relationship between amiodarone and hallucinations independent of delirium has been rarely reported in the literature.

CASE PRESENTATION

We report the case of a 63-year-old female with a history of estrogen and progesterone receptor positive invasive ductal carcinoma with osseous metastases to the ribs and skull, major depressive disorder, and unspecified anxiety. She was diagnosed with invasive ductal carcinoma 12 years prior and underwent a lumpectomy with axillary lymph node dissection and radiation, currently maintained on anastrozole and trastuzumab for the past 11 years. Her symptoms of major depressive disorder and anxiety have remained in remission on a regimen of bupropion extended release, duloxetine, and trazodone without recent dose changes. This patient presented to the emergency department with dyspnea and was admitted to the general medical floor with new-onset atrial fibrillation. She was subsequently started on amiodarone for rhythm control. Shortly after its initiation, the patient developed new onset auditory and visual hallucinations with an unremarkable extensive medical evaluation. Auditory hallucinations consisted of music and unintelligible conversations, while visual hallucinations were of a family member crying on the floor and a man carrying a gun. The differential diagnoses included depression with psychotic features, delirium, and amiodarone-induced hallucinations. Given the lack of current depressive symptoms, absence of altered cognition, and the temporal relationship between the initiation of amiodarone and the onset of hallucinations, amiodarone was suspected to be probable etiology of her hallucinations. For this reason, amiodarone was replaced with dronedarone. Visual and auditory hallucinations ceased within less than 3 days after the discontinuation of amiodarone.

CONCLUSIONS

Psychiatric adverse events from amiodarone are uncommon, and associated isolated hallucinations have only been rarely reported in the literature. While the risk of visual and auditory hallucinations appears to be low with amiodarone initiation, clinicians should be aware of this potential side effect.