title: In vitro effects of co-incubation of blood with artemether/lumefantrine & vitamin C on the viscosity & elasticity of blood.
abstract: OBJECTIVE
  The antimalarial combination drug artemether/lumefantrine has been shown to be effective against malaria parasite through its haemolytic action. This drug is sometimes co-administered with vitamin C in patients with malaria. Vitamin C is associated with antioxidant properties which would be expected to protect against haemolytic effects of this antimalarial drug. This study was designed to investigate in vitro effects of co-incubation of artemether/lumefantrine with vitamin C on the viscosity and elasticity of blood.
  
  
  METHODS
  Blood was collected from 12 healthy female volunteers with normal haemoglobin genotype (HbAA). A Bioprofiler was used to measure the viscosity and elasticity of untreated blood samples (control) and samples exposed to artemether/lumefantrine (0.06/0.36 mg/ml) alone and with low or high dose vitamin C (equivalent to adult doses of 100 or 500 mg).
  
  
  RESULTS
  artemether/lumefantrine significantly (p<0.05) reduced viscosity of blood from 4.72 ± 0.38 to 3.78 ± 0.17 mPa.s. Addition of vitamin C (500 mg) further reduced blood viscosity to 2.67 ± 0.05 mPa.s. The elasticity of blood was significantly (p<0.05) reduced from 0.33 ± 0.04 mPa.s to 0.24 ± 0.03 mPa.s by the antimalarial drug, and further reduced to 0.13 ± 0.02 mPa.s in the presence of vitamin C (500 mg).
  
  
  CONCLUSIONS
  Co-incubation of blood with vitamin C and antimalarial combination drug potentiates the haemolytic effects of the latter on reducing blood viscosity and elasticity in vitro. This may possibly have implications in relation to haemolysis in patients receiving vitamin C supplementation with artemether/lumefantrine during malaria therapy.
authors.affiliation: Department of Basic Medical Sciences (Pharmacology Sections), The University of the West Indies, Mona Campus, Kingston, Jamaica, W.I.
authors.forename: M G
authors.initials: MG
authors.lastname: McKoy
authors.affiliation: Department of Basic Medical Sciences (Pharmacology Sections), The University of the West Indies, Mona Campus, Kingston, Jamaica, W.I.
authors.forename: P
authors.initials: P
authors.lastname: Kong-Quee Iii
authors.affiliation: Department of Basic Medical Sciences (Physiology Sections), The University of the West Indies, Mona Campus, Kingston, Jamaica, W.I.
authors.forename: D J
authors.initials: DJ
authors.lastname: Pepple
mesh_terms: D000328:Adult; D000962:Antimalarials / Q000494:pharmacology; D000077549:Artemether; D037621:Artemisinins / Q000494:pharmacology; D001205:Ascorbic Acid / Q000008:administration & dosage; D001809:Blood Viscosity / Q000187:drug effects*; D004338:Drug Combinations; D004983:Ethanolamines / Q000494:pharmacology; D005260:Female; D005449:Fluorenes / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D000078102:Lumefantrine; D016778:Malaria, Falciparum / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D004338:Drug Combinations; D004983:Ethanolamines; D005449:Fluorenes; D000077549:Artemether; D000078102:Lumefantrine; D001205:Ascorbic Acid