Inclusion Criteria:  An out-of-hospital cardiac arrest survivors treated with targeted temperature management (target between 32 and 36 °C) Presumed cardiogenic cause as cardiac arrest  Exclusion Criteria:  > 12 hours from cardiac arrest to drug or placebo administration previous poor neurological status (Cerebral Performance Categories 3 to 5) patients who have set limitations on treatment (e.g. patients with a signed do-not-resuscitate order) Patients with an underlying terminal-stage disease without an active treatment plan and those who are not expected to survive to discharge patients taking at least 1 g/day of vitamin C or receiving intravenous thiamine prior to enrolment patients experiencing cardiac arrest prior to enrolment or who are expected to die within 24 h despite best possible treatment, based on the judgement of medical personnel pregnant women patients with glucose-6-phosphate dehydrogenase deficiency patients with a history of hypersensitivity reactions to the trial drugs patients with thalassemia patients with hyperoxaluria patients with cystinuria patients with ongoing gout attacks patients diagnosed with oxalate renal stones patients who do not voluntarily consent to participate in the trial (directly or by legal proxy).