Objective: Several drugs can cause analytical interference in clinical laboratory tests.  To prevent errors in clinical judgment as a result of false data, we investigated the information available on the interference of ethical drugs in these tests.
Methods: We examined the information available by collecting and evaluating information in package insert leaflets, collecting and evaluating clinical data on three drugs (bucillamin, captopril, and epalrestat) which affect clinical laboratory test results, and conducting a questionnaire survey of healthcare workers.
Results: From the information available on package inserts, 227 drugs were identified as having the potential to interfere with the chemical reactions used in clinical laboratory tests.  However, the insert information is not sufficient for use in clinical settings because the frequency rate and causative factors of interference are not stated clearly.  The clinical survey results reveal that 40% of patients taking bucillamine and 20% of patients taking epalrestat tested false-positive for urinary ketones.  According to the questionnaire results, medical technologists were more interested than pharmacists and physicians in how drugs affect clinical laboratory tests.
Conclusion: The information currently available on the interference of drugs in clinical laboratory tests is problematical, and it is therefore necessary to collect more clinical data for the proper interpretation and evaluation of abnormal laboratory values.

Objective: The purpose of this study is to compare the clinical efficacy between original drugs and generic products.  Candidate drugs included two types of hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors, simvastatin and pravastatin, because of their importance at reducing the health expenditure for hyperlipidemia.
Design: We retrospectively evaluated the efficacy (total cholesterol, triglyceride, low-density lipoprotein and high-density lipoprotein levels), safety (biochemical parameters), and medication adherence based on patient data.  We set the follow-up period at 6 months before and after substitution.  Data were analyzed by paired-sample t-tests (statistical significance level of 0.05).
Methods: The subjects included in this study were ambulatory patients visiting Nakajima Hospital for dyslipidemia treatment.  Selected patients included those taking both the original drug and the generic product; i.e., patients who had substituted the original drug Lipovas® for the generic product Simvastatin OHARA, or those who had substituted the original drug Mevalotin® for the generic drug Pravatin®.
Results: A total of 118 patients in the simvastatin study and 43 patients in the pravastatin study were candidates for the present study.  We found that there were no significant differences before and after substitution.  Even though there were differences in some of the biochemical parameters, the range remained within normal levels.  With regard to medication adherence, we found no significant differences.
Conclusion: In this study, we found no significant differences before and after substituting medications with generic drugs.  Additionally, we found no subjective symptom changes after substitution.  To develop clinical information on generic products and to store such information, it is important that pharmaceutical products be used appropriately.