title: Warfarin prevalence, indications for use and haemorrhagic events.
abstract: Warfarin, the standard oral anticoagulant drug used in Ireland, is a widely prescribed medication, particularly in the elderly. A HSE Mid-Western Area wide audit was undertaken over a 12-month period to examine the prevalence and indications for warfarin use and haemorrhagic complications associated with the drug. Every patient receiving warfarin therapy over a 13-week period was included (2564). The age standardised rate varied from 0.09% of 35-39 year olds to 6.1% of 80-84 year olds. Atrial fibrillation was the most common indication (54%) in patients attending the Mid-Western Regional Hospital anticoagulation clinic. The annual cumulative incidence of adverse haemorrhagic events in patients with a recorded INR > or = 5.0 episode was 16.6%. The incidence of major and minor haemorrhagic events per INR > or = 5.0 episode was 1.3% and 15.3% respectively. The most common sites of haemorrhage were genitourinary (39%) and gastrointestinal (27%). No fatal or intracranial haemorrhage relating to episodes of over-anticoagulation were reported during the audit period. The most frequent reason for over-anticoagulation was drug interaction (43%). In 74% of patients, the elevated INR was reversed by omitting or reducing warfarin dose. In 17% of cases, vitamin K was administered. Only 3% of incidents were treated with fresh frozen plasma or prothrombin complex concentrates.
authors.affiliation: Department of Haematology, Mid-Western Regional Hospital, Limerick.
authors.forename: W
authors.initials: W
authors.lastname: Ouirke
authors.forename: M
authors.initials: M
authors.lastname: Cahill
authors.forename: K
authors.initials: K
authors.lastname: Perera
authors.forename: J
authors.initials: J
authors.lastname: Sargent
authors.forename: J
authors.initials: J
authors.lastname: Conway
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D001777:Blood Coagulation / Q000187:drug effects; D017723:Drug Utilization Review; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D019934:International Normalized Ratio; D007494:Ireland; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013923:Thromboembolism / Q000517:prevention & control; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin