Pneumocystis carinii pneumonia (PCP) is the most frequent opportunistic infection in patients with AIDS, occurring in 80% and recurring in 50% of patients within 12 months of the first episode. Prophylaxis for PCP is recommended if the CD4+ cell count is <200×106/l or 20% of the total lymphocyte count, or after an episode of PCP. The most effective prophylactic agent currently is trimethoprim-sulphamethoxazole and should be the drug of choice but alternatives such as aerosol pentamidine are being increasingly used for patients who cannot tolerate this combination or other oral preparations. If aerosol pentamidine is used and administered via a Respigard II Marquest nebulizer, the dosage should be higher than the currently recommended monthly dosage of 300 mg.
The Role of Aerosol Pentamidine Prophylaxis