The most effective method for preventing PCP is to eliminate the cause of immunosuppression (e.g., withdraw immunosuppressive therapy, treat HIV infection).
Prophylaxis is indicated for HIV-infected pts with CD4+ T-cell counts <200/µL or a history of oropharyngeal candidiasis and for any pt with a history of PCP. Guidelines for other compromised hosts are less clear, but prophylaxis should be considered for pts receiving >20 mg of prednisone daily (or its equivalent) for ≥30 days.
For prophylactic regimens, see Table 107-2. TMP-SMX is the drug of choice.
For a more detailed discussion, see Masur H, Morris A: Pneumocystis Infections, Chap. 244, p. 1358, in HPIM-19.