title: Chronic chloroquine toxicity and heart block: a report of two cases.
mesh_terms: D000328:Adult; D002738:Chloroquine / Q000008:administration & dosage / Q000009:adverse effects*; D006327:Heart Block / Q000139:chemically induced*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009549:Nigeria
chemical_list: D002738:Chloroquine