Document 0284 DOCN M9620284 TI A preliminary study of ritonavir, an inhibitor of HIV-1 protease, to treat HIV-1 infection. DT 9602 AU Markowitz M; Saag M; Powderly WG; Hurley AM; Hsu A; Valdes JM; Henry D; Sattler F; La Marca A; Leonard JM; et al; Aaron Diamond AIDS Research Center, New York University School of; Medicine, New York 10016, USA. SO N Engl J Med. 1995 Dec 7;333(23):1534-9. Unique Identifier : AIDSLINE MED/96067436 AB BACKGROUND. Ritonavir is a potent inhibitor in vitro of human immunodeficiency virus type 1 (HIV-1) protease, which is needed for virions to mature and become infective. We assessed the safety and efficacy of ritonavir in patients with HIV-1 infection. METHODS. We administered ritonavir orally to 62 patients in one of four dosages during a 12-week trial containing a 4-week randomized, placebo-controlled, double-blinded phase followed by an 8-week dose-blinded phase. We assessed the response with serial measurements of plasma viremia and serial CD4 cell counts. RESULTS. Fifty-two patients completed the 12-week trial. Diarrhea and nausea were the most common side effects, and reversible elevations in serum triglyceride and gamma-glutamyltransferase levels were the most frequent laboratory abnormalities. Ritonavir had a rapid antiviral effect, with a mean maximal reduction in the number of copies of HIV-1 RNA per milliliter of plasma that ranged from 0.86 to 1.18 log in the four dosage groups. After 12 weeks of treatment, the antiviral effect was partially maintained, with a mean reduction in plasma viremia of 0.5 log. When we used a more sensitive assay for HIV-1 RNA in a subgroup of 20 patients, we found that plasma viremia decreased by a mean of 1.7 log. This antiviral effect was partly sustained at week 12, with a mean reduction of approximately 1.1 log. The patients' CD4 cell counts rose during treatment with ritonavir (median increase, 74 and 83 cells per cubic millimeter at weeks 4 and 12, respectively). CONCLUSIONS. The protease inhibitor ritonavir is well tolerated and has a potent antiviral effect, as shown by substantial decreases in plasma viremia and significant elevations in CD4 cell counts. Expanded clinical trials of ritonavir are warranted. DE Adult Antiviral Agents/ADVERSE EFFECTS/PHARMACOKINETICS/*THERAPEUTIC USE CD4 Lymphocyte Count/DRUG EFFECTS Double-Blind Method Female Human HIV Infections/*DRUG THERAPY/IMMUNOLOGY HIV Protease Inhibitors/ADVERSE EFFECTS/PHARMACOKINETICS/ *THERAPEUTIC USE HIV-1/*DRUG EFFECTS Male RNA, Viral/BLOOD Support, Non-U.S. Gov't Support, U.S. Gov't, P.H.S. Thiazoles/*THERAPEUTIC USE Treatment Outcome Valine/*ANALOGS & DERIVATIVES/THERAPEUTIC USE CLINICAL TRIAL JOURNAL ARTICLE MULTICENTER STUDY RANDOMIZED CONTROLLED TRIAL SOURCE: National Library of Medicine. NOTICE: This material may be protected by Copyright Law (Title 17, U.S.Code).