Immediate severe hypersensitivity reaction to etoposide phosphate: Case report and review of the literature.

INTRODUCTION: Hypersensitivity reactions from intravenous (IV) etoposide have been rarely reported, with these being seen more commonly with etoposide than with etoposide phosphate. This is generally explained by the need for polysorbate 80, a known cause of hypersensitivity, as a solubiliser, in the etoposide formulation. CASE REPORT: We report a 22-year-old male, being treated with adjuvant BEP (bleomycin/etoposide phosphate/cisplatin) for a testicular germ cell tumour. Bleomycin and cisplatin were administered without incident. Within one minute of etoposide phosphate commencement he experienced a severe hypersensitivity reaction, consisting of widespread erythematous rash, facial swelling, and nausea. Observations included unrecordable blood pressure, tachycardia, hypoxia, and loss of consciousness, confirming a diagnosis of anaphylactic shock. MANAGEMENT AND OUTCOME: Etoposide phosphate was ceased immediately. He was successfully managed with IV hydrocortisone, IV promethazine, intramuscular adrenaline, IV fluids and oxygen. Following admission for observation, significant improvement occurred over 48 h. DISCUSSION: Hypersensitivity reactions to etoposide were first reported in the 1980s. Following reactions to etoposide, substituting etoposide phosphate into chemotherapy regimens has commonly allowed treatment to continue without incidence. Anaphylactic reactions to etoposide phosphate were first documented in 2012, with further cases reported subsequently. Unlike etoposide, etoposide phosphate is highly soluble in aqueous solutions and doesn't require adjuvants in the formulation. Hypersensitivity reactions to etoposide phosphate are therefore likely related to the etoposide drug molecule itself. Clinicians should be aware of this rare, but potentially life-threatening, toxicity when using etoposide-based treatments and have procedures in place to urgently manage any hypersensitivity reactions that may occur.

Optic neuritis induced by 5-fluorouracil chemotherapy: Case report and review of the literature.

Introduction: For over 50 years, 5-Fluorouracil has played a critical role in the treatment of numerous malignancies, including colorectal cancer. Ocular side effects are uncommon and include blurred vision, conjunctivitis, excessive lacrimation and keratitis. Case report: We report a 57-year-old male with metastatic colorectal cancer who had received extensive chemotherapy with 5-Fluorouracil-based regimens for over 12 months. Following his seventh cycle of cetuximab/FOLFIRI, he developed acute onset global headache, nausea and loss of vision in the right eye. After detailed investigations, including ophthalmologic and neurologic consultations, a diagnosis of optic neuritis was made. Management and outcome: Chemotherapy was ceased immediately, and intravenous methylprednisolone (1 g) daily for five days was commenced. His headache resolved and vision started to improve within 24 h. Three weeks after completion of corticosteroids, constriction of the right visual field had fully resolved. Discussion: Atypical optic neuritis is an inflammatory optic neuropathy that can be caused by ischaemia, mechanical compression, nutritional deficiency, toxins and drugs. Drug-induced optic neuritis, while rare, is associated with cytotoxic medications including methotrexate, cisplatin, carboplatin, vincristine and paclitaxel. There have only been five previous case reports implicating 5-Fluorouracil in the development of optic neuropathy. The likelihood of the adverse drug reaction due to 5-Fluorouracil was assessed using the Naranjo algorithm. A score of +7 indicates probable causality. Clinicians should be alert to this potential ocular toxicity in order to initiate prompt cessation of treatment and early ophthalmology referral to prevent visual loss and damage to ocular structures.