Megadose of Hydroxocobalamin for the Treatment of Pernicious Anemia

Inclusion Criteria: Age \>18, All sex Clinical suspicious of megaloblastic anemia ( cytopenias and macrocytosis (CBC), hypersegmented neutrophils and elevated lactate dehydrogenase) Patients must sign an informed consent indicating that they are aware of the investigational nature of this study - Exclusion Criteria: Administration of hydroxocobalamin in the three years before enrollment Patients with active, uncontrolled psychiatric disorders Severe neurologic deficit Known hematologic malignancy Known coagulation disorder that contraindicates intramuscular injection End-stage kidney disease (GFR \<15ml/min) Chronic liver disease (Child-Pugh B or C) Pregnant patients Known infection of Hepatitis B or C and HIV Diagnosis of myelodysplastic syndrome \-