The rate of antibiotic dosage adjustment in renal dysfunction

The purpose of this study was to determine the number of prescribed antibiotics being appropriately adjusted and to assess antibiotics with the highest incorrect dosing based on the patient's renal function according to distinguished guidelines. The study was conducted at a 446-bed university hospital. One hundred and fifty patients admitted through different wards of the hospital were included in the study. Demographic data were extracted and creatinine clearance was calculated using either Cockcroft-Gault (C&G) or Modification of Diet in Renal Disease (MDRD) formula. In patients with creatinine clearances less than 50 mL/min, antibiotic dosages were compared with guideline dose recommendations to judge whether they were correctly adjusted. Two hundreds and ninety-one instructions (79.9%) of 364 antibiotic prescriptions required dosage adjustment based on the patient's renal condition. These adjustments were rationally performed in 43.7% and 61.4% of prescriptions, according to the two guidelines used. Ciprofloxacin (29.1% of cases), and vancomycin (33.6% of cases), were the most inappropriate prescribed antibiotics in terms of dose administration. Drug dosing adjustments should be emphasized in patients with renal dysfunction. Failure to do so may lead to higher morbidity and mortality as well as therapeutic costs. Estimating creatinine clearance prior to drug ordering and use of a reliable dosing guideline is highly recommended.