Acute Kidney Injury Following Posaconazole for Mucormycosis: SARS-CoV-2 as a Back-Seat Driver

Viruses have been implicated in the causation of several systemic illnesses, either directly or by immune modulation. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not an exception. Due to altered immune regulation, it is often associated with novel clinical manifestations and complications which have not been reported before. SARS-CoV-2 induces a pro-inflammatory state which makes the patient vulnerable to developing a variety of previously unreported adverse reactions to medications. Coronavirus disease 2019 (COVID-19) and its treatment have provided a fertile ground for various opportunistic infections including mucormycosis. The standard treatment for mucormycosis is surgical debridement and liposomal amphotericin B. Triazole antifungals such as posaconazole and isavuconazonium are the second-line agents for those intolerant to first-line therapy. Posaconazole is safer than amphotericin B as far as renal adverse effects are concerned. We report the case of a 60-year-old lady with type 2 diabetes mellitus, hypertension, ischemic heart disease, and osteoarthritis. She had severe COVID-19 requiring non-invasive ventilation four months ago. She presented with right rhino-orbital swelling, diplopia, and serosanguinous discharge from the right nostril. She had right third, sixth, and seventh cranial nerve palsies. Magnetic resonance imaging revealed right maxillary, ethmoid, and frontal sinusitis. Biopsy from the right nostril confirmed mucormycosis. Having normal renal and liver functions, she was started on oral posaconazole as she had an allergic reaction to a test dose of 1 mg amphotericin B (non-liposomal) in 20 mL of 5% dextrose water infused over 30 minutes. On day five, she developed acute kidney injury requiring renal replacement therapy. Her posaconazole was stopped. As she was not improving with conservative treatment, an ultrasound-guided, percutaneous renal biopsy was performed from the left kidney. The renal biopsy revealed thrombotic microangiopathy. She was started on liposomal amphotericin B as decided by the multidisciplinary team. Her renal function improved, and she continued on liposomal amphotericin B. We conclude that thrombotic microangiopathy, in this case, was likely due to posaconazole. This is a novel adverse effect presumably of posaconazole. This case report will alert physicians to be vigilant of the renal adverse effects of posaconazole in patients who have had COVID-19. Patients who develop renal injury while on posaconazole should undergo an early renal biopsy to ascertain the exact histopathology.