. Drug Related Problems (DRPs) are of major concern because of physical, psychological and economical implications for the patients and for society. The potential risk factor for DRPs is polypharmacy. The aim of this study was to evaluate the influence of drug information to the doctors for decreasing drug related problems on cardiovascular patient prescriptions at X pharmacy Jakarta. The method of this study was experimental with two groups pretest and posttest designs. Samples were Health Insurance (Askes) patient prescriptions that diagnose cardiovascular desease, above 40 years old age with two hundreds prescriptions each groups. The intervention to the doctor was a letter about analysis of drug related problems (DRPs) which found at prescriptions. The DRPs's studies were drug interactions, subtherapy doses, supratherapy doses, non Plafon and Price List of PT.Askes's Standard Drugs (DPHO) giving and polypharmacy. The results showed that the amount of drugs in a control group was 6.45 items, mode 7 items, non DPHO drugs 0.92 items, the price of one prescription was Rp. 229.471 andthe cost by the patient was 13.42 %. The amount of drugs in an intervention group was 6.06 items, mode 6 items, non DPHO drugs 0.67 items, the price of one prescription was Rp. 206.298 and the cost by the patient was 12.72%. DRPs found were drug interactions, non DPHO drugs giving and polypharmacy. There were no sub therapy doses and supra therapy doses at prescriptions. The influence of interventions to the doctor for decreasing drug related problems in a drug interactions and polypharmacy were significant, butdecreasing of non DP HO drugs giving was not significant. The number of drugs in oneprescription decreasing lowered price of total drugs. Key words : Drug related problems (DRPs), drug interaction, cardiovascular drugs, Health Insurance, prescription.