Background Enoxaparin is a safe drug but could cause adverse effects if it accumulates.

Purpose To assess the renal function in patients requiring enoxaparin admitted to several wards in our hospital.

Materials and methods The authors conducted a prospective observational study for a month (March 2010) which involved the review of prescriptions for enoxaparin on the traumatology, internal medicine and geriatrics wards. The authors recorded the dose of enoxaparin, other drugs prescribed, age and serum creatinine (Cr). The authors calculated the creatinine clearance (CrCl) with abbreviated MDRD in patients with Cr values over 1.1 mg/dl. According to the product information for Clexane, the dose should be adjusted in patients with CrCl≤30 ml/min and clinical monitoring is recommended with CrCl=30–50 ml/min. The standard treatment for deep vein thrombosis is 1 mg/kg/24 h and for thromboembolic disease prophylaxis it is 20 mg/24 h. The authors advised prescribing physicians of potentially risky patterns in writing through the prescription process. The authors drew their attention to patients with CrCl<30 ml/min and patients aged over 75 prescribed excessive doses of enoxaparin.

Results Enoxaparin was prescribed to 256 patients, 85 in traumatology, 130 in internal medicine and 41 in geriatrics. The authors detected 141 potential risk patterns: 81 in internal medicine, 37 in traumatology and 23 in geriatrics. Among these 141, 120 were due to high doses of enoxaparin in patients aged over 75 and the remaining 21 were patients with CrCl<30 ml/min. The distribution pattern of the risk was: 36 in traumatology because of age and none for CrCl, 65 in internal medicine due to age and 16 due to CrCl, and 19 in geriatrics due to age and 5 due to CrCl. After alerting the doctors, five treatment regimens were changed.

Conclusions More than half (55%) of the prescriptions analysed were potentially dangerous considering the renal function, and in most cases no change was made after the Pharmacy department drew attention to the risk. Enoxaparin is a safe drug but more attention should be paid to the kidney function of treated patients.