Establishing Appropriate Withdrawal Periods for Anticoagulants and Antihypertensive Medicines before Surgery

Patients admitted for surgical procedures have often taken a variety of medicines for heart disease or hypertension in addition to those for their underlying diseases.In this study,we examined the withdrawal periods for anticoagulants and antihypertensive medicines before surgery,and investigated the effect of angiotensin II receptor (ATII) antagonists on blood pressure during surgery.In July 2005,300 patients underwent surgical procedures in the Day-Surgery Unit and 314 in the surgical wards (excluding ophthalmology).We prepared a chart of recommended withdrawal periods before surgery,and based on it investigated the withdrawal periods for these patients.Furthermore,patients were assigned to 2 groups : Group I in which ATII antagonists were withdrawn 24 hours prior to surgery or earlier (n=10); and Group II,in which ATII antagonists were administered in the morning of the day of surgery day (n=9),and compared blood pressures between two groups.Forty-four patients (16.7%) in the Day-Surgery Unit and 47 patients (15.0%) in the surgery wards had been taking anticoagulants,angiotensin converting enzyme inhibitors or ATII antagonists.In the case of 10 patients in the Day-Surgery Unit and 12 patients in the surgery wards,anticoagulants were not discontinued sufficiently long enough before surgery.Further,patients who had been taking ATII antagonists had lower systemic blood pressures and more frequent episodes of hypotension than those not on ATII antagonists,although these differences were not statistically significant.In conclusion,pharmacists should provide doctors with adequate information regarding times of drug withdrawal to reduce risks while patients are under anesthesia.