Dapsone-pyrimethamine compared with aerosolized pentamidine as primary prophylaxis against Pneumocystis carinii pneumonia and toxoplasmosis in HIV infection. The PRIO Study Group.

BACKGROUND: Pneumocystis carinii pneumonia and toxoplasmic encephalitis are frequent life-threatening opportunistic infections in patients with human immunodeficiency virus (HIV) infection. Primary prophylaxis against P. carinii pneumonia is now common, but there are few data on regimens for primary prophylaxis against toxoplasmosis. METHODS: We conducted a randomized trial that compared two prophylactic regimens: dapsone (50 mg per day) plus pyrimethamine (50 mg per week) was compared with aerosolized pentamidine (300 mg per month). The patients had symptomatic HIV infection, no history of P. carinii pneumonia or symptomatic toxoplasmosis, and CD4+ counts below 200 per cubic millimeter (0.2 x 10(9) per liter). RESULTS: In an intention-to-treat analysis, after a median follow-up of 539 days P. carinii pneumonia developed in 10 patients in each group, whereas toxoplasmosis developed in 32 of 176 patients in the pentamidine group and 19 of 173 patients in the dapsone-pyrimethamine group. Those assigned to pentamidine had a risk of P. carinii pneumonia that was similar to the risk in those assigned to dapsone-pyrimethamine (adjusted relative risk, 1.13; 95 percent confidence interval, 0.44 to 2.92; P = 0.79), but a higher risk of toxoplasmosis (adjusted relative risk, 1.81; 95 percent confidence interval, 1.12 to 2.94; P = 0.02). Among the 262 patients with serologic evidence of past exposure to Toxoplasma gondii, the relative risk of symptomatic toxoplasmosis was 2.37 times higher in those assigned to pentamidine (95 percent confidence interval, 1.3 to 4.4; P = 0.006). More patients discontinued dapsone-pyrimethamine than pentamidine because of toxicity (42 vs. 3; P < 0.001). Survival was similar in the two groups. CONCLUSIONS: For primary prevention of P. carinii pneumonia, dapsone-pyrimethamine is as effective, though not as well tolerated, as aerosolized pentamidine. Dapsone-pyrimethamine also prevents first episodes of toxoplasmosis.

[Evolution of the definition of AIDS. The main classifications of HIV infection]. / Evolution de la définition du SIDA. Principales classifications de l'infection par le VIH.

The purpose of this paper is to trace the evolution of AIDS definition and describe the principal classification systems of HIV infection as defined since 1981. Our work is principally based on data from the American Centers of Disease Control on the one hand (clinical evaluation of infection stage) and from the Walter Reed Institute (immunological evaluation of infection stage) on the other hand. To describe this disease with multiple aspects the separate use of these two classification systems does not provide a thorough evaluation of the patient's condition. Non consensus had been reached to date, although an agreement on this matter would foster an important epidemiological and therapeutic progress in both adult and childhood patients.

Comparison of plasma concentrations of aerosolized pentamidine in nonventilated and ventilated patients with pneumocystosis.

Pentamidine concentrations were determined in plasma after a single aerosolization of 4 mg/kg pentamidine base on 18 patients breathing spontaneously (Group I) and in eight patients receiving mechanical ventilation (Group II). All the patients had documented pneumocystosis. Large interindividual variations in concentrations appeared, especially in Group I. Low concentrations were observed in Group I: Cmax = 65.6 +/- 9.4 micrograms/L (mean +/- SEM), contrasting with high levels in Group II: Cmax = 215.8 +/- 49.8 micrograms/L (mean +/- SEM). Consequently, the mean area under the curve from zero to 4 h was 2.6-fold higher in Group II than in Group I. These findings underline the risk of dose-related pentamidine toxicity in ventilated patients treated with aerosolized pentamidine and the interest of plasma pentamidine monitoring.

Comparison of tissular disposition of pentamidine mesylate in the rat after aerosol or parenteral administration.

The tissular distribution of pentamidine mesylate (4 mg/kg as free base) after intravenous, intramuscular, and aerosol administration in healthy rats was examined. Pentamidine levels in the plasma, lungs, liver, kidneys, and other organs were determined by high-performance liquid chromatography. Pentamidine was undetectable in the plasma after day 5. At day 1, the injected groups had high concentrations of the drug in the kidneys (32-34 micrograms/g) and spleen with much lower concentrations in the lungs and the liver (3.12-5.70 micrograms/g and 1.64-2.19 micrograms/g, respectively). Aerosol delivery of pentamidine produced negligible extrapulmonary drug levels (3.29 micrograms/g in kidneys at day 1) and high sustained pulmonary levels throughout the 60 d of the study (range 5.42-19.62 micrograms/g). The half-time of elimination was longer in the lungs and kidneys (29-45 d) than in the liver (1.4-7.0 d) regardless of the mode of administration.