Inclusion Criteria:  child or adolescent aged 1 year to 17 years and 10 months, followed at the Necker-Enfants malades Hospital for a SS or Sβ0 SCD; having at least one vaso-occlusive crisis in the year prior to inclusion; for young girl of childbearing age (≥ 15 years old), a negative pregnancy test; signed informed consent of the 2 parents or legal representative(s) and of the child of expressive age or the adolescent; beneficiary of social security coverage or entitled (excluding AME)  Exclusion Criteria:  treatment with crizanlizumab (anti-P-selectin antibody); treatment with atazanavir/ritonavir in combination with tenofovir; known hypersensitivity to famotidine or to other histamine type 2 (H2) receptor antagonists; cardiovascular history such as: arrhythmia, AVB (atrioventricular block), QT prolongation; renal failure characterized by creatinine clearance <60 mL/min; hepatic cytolysis (ALT ≥ 3N); neutropenia (<1 G/L), thrombocytopenia (<80 G/L), reticulopenia (<80 G/L); predictable poor adherence to treatment; pregnancy or breastfeeding; participation in another interventional research involving the human person; planned bone marrow transplant or gene therapy within one month of inclusion.  Within 3 months prior to inclusion:  red blood cell transfusion; introduction of hydroxyurea or modification of hydroxyurea doses; introduction of L-glutamine or modification of L-glutamine doses; introduction of voxelotor or modification of voxelotor doses; taking oral or IV corticosteroids or any other immunomodulatory treatment; taking an antihistamine treatment  In the month preceding inclusion:  occurrence of a vaso-occlusive crisis, acute chest syndrome or any vaso-occlusive phenomenon (acute splenic sequestration, priapism, stroke, occlusion of the central retinal artery, papillary necrosis); occurrence of fever (≥ 38°C) or any infectious episode, febrile or not, suspected or confirmed, of a viral, bacterial, fungal or parasitic nature ; occurrence of an acute hemolytic episode (increase in jaundice and pallor, decrease in hemoglobin level of ≥ 1 g/dL compared to baseline hemoglobin, increase in LDH and/or AST and/or free bilirubin deemed significant by the child's referring physician).