EFFECT OF AGE ON WARFARIN DOSE REQUIREMENT IN PAKISTANI POPULATION

Abstract

Objective: The study was conducted to determine the effect of age on warfarin
dose requirement in Pakistani population.
Methodology: This cross-sectional study was carried out at Armed Forces
Institute of Cardiology (AFIC) Rawalpindi, Military Hospital Rawalpindi and
National Institute of Cardiovascular Diseases (NICVD), Karachi from October
2010 to March 2012. Stable patients receiving warfarin were recruited after
detailed medical history, physical examination and laboratory tests. The
demographic and clinical data of individuals was recorded in a pre-structured
proforma. Data was analyzed using SPSS version 20.0. Pearson correlation
coefficient was calculated to study the relationship of dose with age. A p-value of
less than 0.05 was taken as statistically significant.
Results: A total of six hundred and seven (607) stable patients fulfilling the
eligibility criteria, participated in the study. The mean age of patients was
37.93±12.23 years (range 18-65 years). Mean daily dose of warfarin calculated
in 607 patients was 5.62±1.98 mg with the range of 0.36-15 mg whereas mean
weekly dose was 39.36±13.8 mg with the range of 2.5-105 mg. There was
negative correlation between age and warfarin (correlation coefficient r = -
0.091) which was statistically significant as p-value was less than 0.05 (p =
0.026).
Conclusion: It is concluded that with increasing age, lesser dose of warfarin is
required in Pakistani population to produce the same therapeutic anticoagulant
response.