Objective : The Pharmacy and Therapeutic Committee generally selects formulary drugs by evaluating the comparative data from non-clinical and clinical studies of pharmacologically similar type drugs. Usually there are few data from directly comparative studies among all similar type drugs, and there are only two types of studies, standard drug or placebo-control study. In this situation, it is very difficult to select the superior drug.
Therefore, we conducted a retrospective cohort study to compare the efficiency among three 5-HT₃ antagonists and to investigate the possibility of data from this study, as a reference for decision making.
Design : Retrospective cohort study.
Methods : A retrospective cohort was assembled comprising in-patients of to Surgery, Obstetrics and Gynecology, Ophthalmology, Orthopedics, Dermatology, Psychiatry, or Thoracic Surgery Departments, who received chemotherapy and a 5-HT₃ receptor antagonist from January to June in 1996. We compared the side effects of nausea and vomiting among patients receiving various 5-HT₃ receptor antagonists. Physicians could freely prescribe three 5-HT₃ antagonists that were adopted in our hospital during the period. Pharmacists collected information regarding the efficacy of 5-HT₃ receptor antagonists on the first prescribed day by reviewing medical charts, nurses' reports and interviews with the nurses.
Statistical Analysis : ANOVA was used for testing the age differences among patients receiving 5-HT₃ receptor antagonists. Chi-square was used for testing difference of sex, administration route, number of chemotherapy treatment. Kruskal-Wallis rank test was used for testing the difference of efficacy. Probabilities less than 5% (P<0.05) were considered significant.
Results : Out of 68 patients, 35% received cisplatin and 65% received non-cisplatin anti-tumor drugs. The average age was 53.1±17.4 (49% male, 51% female). A total of 82% received intravenous drip injection.
Percentage of non-changed cases in ingestion ratio was 32% of ramosetron, 50% of ondansetron and 53% of azasetron. There was no significant difference in the ingestion ratio (p = 0.026).
Percentage of non-changed cases with regard to vomiting (complete control) was 80% of ramosetron, 50% of ondansetron, 79% of azasetron. There was a significant difference in vomiting (completecontrol) (p = 0.044). Ondansetron was less effective as an antiemetic function.
Discussion : When no data from a directly comparative study are available to determine the adoption of a new medicine from among numerous candidate drugs, an observational study such as this appears useful.

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It is well known that oral contraceptives (OC_s) are still not available in Japan while there are considerable voices for the introduction. On the other hands, there are apprehension about safety of OC_s. This report outlines the safety issue of OC_s, especially that of newer products belonging to the 2nd and 3rd generations concerning cardiovascular and cerebrovascular accidents and risk of some cancers.
The members of the Pharmacoepidemiology Committee of RAD-AR Council, Japan reviewed original articles regarding this issue, shared information which was given by the articles, and provided this report. The articles were selected from recent reports of pharmacoepidemiology studies published after January of 1996 in major medical journals ; the Lancet, the British Medical Journal, the New England Journal of Medicine, and the Journal of American Medical Association, as well as some former references cited by these articles. These studies have assessed various risks among OC users in comparison with non users or by comparing different types of OC_s, and investigated relationship between adverse events and various aspects of oral contraceptive use, such as doses, duration, and timing of use, and various risk factors which users may have.
Although most authors explained their findings cautiously within limitations of observational studies, the results gave considerable impact on the public and regulatory authorities. This kind of pharmacoepidemiology studies based on real world are considered to be indispensable to realize appropriate use of drugs.

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Background : With a support from Ministry of Health and Welfare (MHW) Japan, we embarked on a pilot study for Prescription-Event Monitoring (PEM) adapted to Japanese environment.
Methods : A pilot study was conducted according to the report on this subject to MHW in 1996.
Results and Conclusion : PEM using monthly claims called as “Rezept” issued by individual hospitals and clinics is judged to be difficult unless the use of the claims for epidemiological studies is legally separated from the examination process of the medical cost claimed. PEM using the prescriptions dispensed by individual pharmacies is easier to conduct. Some progress has been attained by employing the latter scheme in the pilot study where approximately 1300 patients with a new antidiabetic agent, troglitazone, are compared with 1300 patients who have recently started one of “old” antidiabetics.

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