The primary objective of this study is to compare cost -effectiveness of two anti-retroviral regimens, azidothymidine (AZT) and azidothymidine switchto didanosine (ddI), in HIV-infected patients. Moreover, both the treatmenteffect and side effects of AZT and ddI were also identified. Treatment effectwas measured in term of months without AIDS. Only anti-retroviral drug cost(direct cost) was collected and measured in terns of baht. Symptomaticpatients who were not pregnant, not under 15 years old and first attendedBamrasnaradura Hospital from July 1, 1994 to June 30, 1995 were recruited inthis study. From 40,888 patients who first attended the hospital, 1,267 patientspresented with complaints associated with HIV infection. Of these 1,267patients, 105 (8.29%) were symptomatic patients. First-visit symptoms wereoral candidiasis or hairy leukoplakia (53.33%), diarrhea(46.67%), cachexia(41 .90%), and fever (28.57%). Only 27 (25.7 1 %) symptomatic patientsreceived anti-retroviral drug. Nineteen patients were assumed to continuouslytake anti-retroviral drug because they met the physician every appointment. Inother words, 19 patients were compliant with therapy. One patient did not turn into AIDS, so 18 patients were eligible for disease progression analysis.Fourteen patients received AZT (regimen 1). Four of 18 patients switched fromAZT to ddI because of anemia (3), nausea and vomiting (1). Time to AIDS was 9.08 months (1.84- 16.73) for AZT group compared with 15.5 1 months (10.95-17.95) for AZT switch to ddI group. It is statisticallydifferent with p-value < 0.05 at 95% CI. Anti-retroviral cost was 12,797.55baht (2,593.92-23,576.88) and 28,520.14 baht (1 9,369.63-30,344.16) for AZTand ddI group respectively. The second regimen (ddI group) costs 2,445.19baht per an extra month without AIDS.

M.Sc. (Pharmacy : Hospital Pharmacy มหาวิทยาลัยมหิดล ปี 2540

effectiveness, Cost, Anti-HIV, AZT, ddI