High-dose N-acetylcysteine in an immunocompromised patient with COVID-19

On 19 June 2022, a 45-year-old man was admitted to intensive care unit with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia.His body mass index was 22.3.He had a history of hypertension, diabetes mellitus, hyperlipidaemia, and immunoglobulin A nephropathy.He had been receiving prednisolone and mycophenolate mofetil following a renal transplant.His baseline creatinine level was 203 µmol/L.Three doses of CoronaVac vaccine had failed to induce an antibody response.The patient was in septic shock and had respiratory failure and acute renal failure.He had myopericarditis with elevated level of serum troponin I, diffuse ST elevation on electrocardiogram, and impaired left ventricular ejection fraction of 40% on echocardiogram.Coronary angiogram on 21 June 2022 was normal and myocardial biopsy revealed increased interstitial macrophages.Urine contained Enterococcus faecalis but no white blood cells on microscopy.Screening for other bacterial, viral or fungal co-infections was negative.He was prescribed intravenous remdesivir 200 mg once followed by 100 mg every 12 hours for four more doses and intravenous hydrocortisone 100 mg every 8 hours, and the nephrologist discontinued his mycophenolate mofetil treatment.He received broad spectrum antibiotics as directed by infectious disease specialists.Enoxaparin 60 mg was administered subcutaneously every 48 hours for prophylaxis of deep vein thrombosis.Infectious disease specialists did not recommend tocilizumab, baricitinib, monoclonal antibodies, or convalescent plasma.The patient received intravenous high-dose N-acetylcysteine at a dose appropriate for treatment of paracetamol overdose as treatment of influenzainduced cytokine storm.Animal studies have shown that an oral dose of N-acetylcysteine 1 g/kg/day improved the survival of mice with otherwise lethal influenza infection and was synergistic with oseltamivir with an endpoint survival of 100%. 1 Human oral availability of N-acetylcysteine is 6% to 10%.We have reported previously successful treatment of a patient with 2009 H1N1 influenza virus