Prophylaxis for Pneumocystis carinii pneumonia ( PCP ) is recommended for all HIV-infected children considered to be at high risk. Approximately 15 percent of children are intolerant to trimethoprim / sulfamethoxazole, the first choice drug for PCP prophylaxis. Since many children are also unable to take or tolerate aerosolized pentamidine, dapsone is a second choice for PCP prophylaxis. The most favorable dose regimen for dapsone has not been established.~Ninety-six HIV-infected infants and children who are intolerant to trimethoprim / sulfamethoxazole ( TMP / SMX ) are randomized to receive oral dapsone in a lower dose once daily or at a higher dose once weekly. Treatment continues until the last patient enrolled has received at least 3 months of therapy. Blood samples are drawn between weeks 4 and 8, at weeks 12 and 24, and every 3 months thereafter during dapsone administration.
Primary: To compare the toxicity of daily versus weekly dapsone in HIV-infected infants and children; to study the pharmacokinetics of orally administered dapsone in HIV-infected infants and children.~Secondary: To obtain information on the rate of Pneumocystis carinii pneumonia ( PCP ) breakthrough in children receiving two different dose regimens of dapsone.~Prophylaxis for Pneumocystis carinii pneumonia ( PCP ) is recommended for all HIV-infected children considered to be at high risk. Approximately 15 percent of children are intolerant to trimethoprim / sulfamethoxazole, the first choice drug for PCP prophylaxis. Since many children are also unable to take or tolerate aerosolized pentamidine, dapsone is a second choice for PCP prophylaxis. The most favorable dose regimen for dapsone has not been established.