[Anti-retroviral therapy of HIV-infection. With preliminary results of the Swiss postmarketing surveillance of zidovudine].

: In the last few years, the treatment of HIV infection has advanced considerably due to the development of active antiretroviral compounds. Many substances with different mechanisms of action show strong activity against HIV in vitro and many of them are now under clinical investigation. But immense effort is needed to develop a clinically effective and tolerable drug for daily use from a substance active in vitro. Presently, zidovudine is the only drug that can be used for the treatment of HIV infection outside of clinical studies. The efficacy of zidovudine was demonstrated in patients with symptomatic HIV infection as well as in patients with advanced asymptomatic disease. The clinical signs of efficacy are significantly delayed progression of HIV infection and lower frequency of opportunistic infections, with decreased severity. It is evident that zidovudine does not cure the HIV infection. In Switzerland treatment with zidovudine is evaluated by post-marketing surveillance (PMS). All patients on zidovudine are seen periodically in the hospitals with a specialized division for HIV infection. Clinical and laboratory follow-ups are recorded. Until the beginning of October 1990, 1171 patients with symptomatic HIV infection have been treated with zidovudine in the setting of this PMS. 62% of all registered patients are currently receiving zidovudine. 20% died of AIDS. 15% of all patients received at least one blood transfusion. Hematotoxicity is the most frequent and serious side effect of zidovudine and can require definitive termination of therapy. The side effects are dose related and occur more severely in patients with advanced disease. The ideal dosage of zidovudine has not yet been defined. Recently published studies showed efficacy with doses as low as 500 mg/d. Consequently, patients in Switzerland receive 10 mg zidovudine/kg body weight as the maximum dose, divided into two or more single daily doses. Patients with asymptomatic HIV infection are regularly treated with 500 mg/d. Zidovudine-intolerant patients with symptomatic HIV infection can currently enter a controlled clinical trial of antiretroviral therapy with dideoxyinosine (ddI), which has a different spectrum of side effects but is only minimally toxic to bone marrow.