title: Use of fondaparinux as an anticoagulant during hemodialysis: a preliminary study.
abstract: OBJECTIVE
  To study the effect of fondaparinux, a new antithrombotic agent, as an anticoagulant during a 4-hour conventional hemodialysis session. materials and methods: Fondaparinux was administered as an anticoagulant to 16 chronic hemodialysis patients during a single 4-hour hemodialysis session at an intravenous bolus dose of 2.5 mg. Eight patients were using high-flux polyester polymer alloy (PEPA) dialyzers (Group A) and the remainder low-flux polysulfone dialyzers (Group B), whilst all had received conventional doses of tinzaparin sodium as an anticoagulant during the previous month. The dialyzers were primed with 1 l of normal saline containing 5,000 IU of unfractionated heparin. Blood samples for the measurement of INR, APTT (activated partial thromboplastin time) and anti-Xa levels were taken before the study dialysis session (pre), 5 min postdialysis (post), and before the next dialysis session (next). Mean fibrin/clot formation in the extracorporeal circuit and dialyzer was assessed macroscopically by visual inspection and was graded using a 4-point scale.
  
  
  RESULTS
  Predialysis anti-Xa levels were 0.04 A+/- 0.03 IU/ml in Group A, and 0.025 A+/- 0.025 IU/ml in Group B (p = NS). Postdialysis anti-Xa levels were significantly higher than predialysis levels in both groups (Group A = 0.16 A+/- 0.04 IU/ml, Group B = 0.46 A+/- 0.12 IU/ml, p < 0.02 for both) and significantly higher in Group B compared to Group A (p < 0.025). Anti-Xa levels before the next dialysis session were 0.06 A+/- 0.04 IU/ml in Group A and 0.25 A+/- 0.06 IU/ml in Group B (p < 0.0001 between Groups A and B). APTT values were significantly higher in postdialysis than predialysis samples for both groups (higher by 27.0 A+/- 26.0% in Group A and 24.3 A+/- 31.9% in Group B). No significant differences were found when comparing APTT values in pre, post and next samples between Groups A and B. No differences were also found between pre, post and next samples for INR values, either within or between groups. Mean fibrin/ clot formation score in the extracorporeal circuit at the end of the study dialysis session was significantly higher in patients of Group A than those of Group B (p < 0.05). Dialysis had to be terminated before the completion of 4 hours in 2 patients of Group A because of the presence of extensive fibrin/clots in the circuit and dialyzer.
  
  
  CONCLUSIONS
  Our findings indicate that fondaparinux sodium at an intravenous dose of 2.5 mg can be used successfully as an anticoagulant during a 4-hour conventional hemodialysis session in patients dialyzed with low-flux polysulfone dialyzers, but not in those dialyzed with high-flux dialyzers. However, anti-Xa levels in the former patients were still increased before the next dialysis session, potentially exposing the patients to an increased risk of bleeding.
authors.affiliation: Renal Unit, G.H. G. Papanikolaou, Vas. Olgas 82, Thessaloniki, Greece.
authors.forename: K I
authors.initials: KI
authors.lastname: Sombolos
authors.forename: T K
authors.initials: TK
authors.lastname: Fragia
authors.forename: L C
authors.initials: LC
authors.lastname: Gionanlis
authors.forename: P E
authors.initials: PE
authors.lastname: Veneti
authors.forename: G I
authors.initials: GI
authors.lastname: Bamichas
authors.forename: S K
authors.initials: SK
authors.lastname: Fragidis
authors.forename: I E
authors.initials: IE
authors.lastname: Georgoulis
authors.forename: T A
authors.initials: TA
authors.lastname: Natse
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000627:therapeutic use; D002908:Chronic Disease; D065427:Factor Xa Inhibitors; D005260:Female; D000077425:Fondaparinux; D006801:Humans; D007275:Injections, Intravenous; D019934:International Normalized Ratio / Q000379:methods; D007674:Kidney Diseases / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D011134:Polysaccharides / Q000008:administration & dosage* / Q000627:therapeutic use; D006435:Renal Dialysis
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D011134:Polysaccharides; D000077425:Fondaparinux