A Double-Blind Study To Evaluate the Long-Term Safety and Effectiveness of 60 mg Versus 120 mg of Aerosol Pentamidine in the Prophylaxis of Pneumocystis Carinii Pneumonia in AIDS Patients

Inclusion Criteria Patients who have completed 16 treatments under Fisons study no. 87-71 entitled, "A Double-Blind Group Comparative Study To Evaluate the Safety and Effectiveness of Three Different Doses of Aerosol Pentamidine in the Prophylaxis of Pneumocystis Carinii Pneumonia in Patients With AIDS Post First Episode PCP." Detailed safety parameters must have been documented for 6 months. * Patients must receive the first dose on this study within 2 weeks of their last dose under study no. 87-71. Exclusion Criteria Co-existing Condition: Patients with the following are excluded: * Requiring ongoing active therapy for an opportunistic infection (O.I.) at time of entry or those patients with either of the following AIDS-defining O.I.'s at entry: * Toxoplasmosis. * Cryptococcosis. * Pulmonary Kaposi's sarcoma. * Asthma poorly controlled by medication. * Receiving active therapy for tuberculosis. Patients with the following are excluded: * Requiring ongoing active therapy for an opportunistic infection (O.I.) at time of entry or those patients with either of the following AIDS-defining O.I.'s at entry: * Toxoplasmosis. * Cryptococcosis. * Pulmonary Kaposi's sarcoma. * Unwilling to sign informed consent. * Cannot cooperate with study procedures. * Asthma poorly controlled by medication. * Receiving active therapy for tuberculosis. Active substance abuse.