A 35-year-old HIV-positive patient has a CD4 count of 45 cells/μL and is not on ART. He develops fever, night sweats, and elevated serum LDH. Chest CT shows bilateral pulmonary infiltrates. BAL lavage with Gomori methenamine silver (GMS) stain shows cup-shaped intracystic bodies. The preferred treatment for moderate-severe Pneumocystis jirovecii pneumonia (PCP) is:

• A IV pentamidine
• B IV trimethoprim-sulfamethoxazole (TMP-SMX) plus adjunctive corticosteroids (if PaO2 <70 mmHg or A-a gradient >35) ✓
• C Oral atovaquone
• D Caspofungin

Explanation

TMP-SMX (15–20 mg/kg/day trimethoprim component IV or oral for 21 days) is the first-line treatment for all severities of PCP in HIV. For moderate-severe PCP (PaO2 <70 mmHg on room air or A-a gradient >35 mmHg), adjunctive corticosteroids (prednisolone 40 mg BD × 5 days, then 40 mg OD × 5 days, then 20 mg OD × 11 days) reduce inflammatory response and mortality. IV pentamidine is an alternative for TMP-SMX-intolerant patients but has significant toxicity. Atovaquone is used for mild PCP and prophylaxis. Caspofungin has no activity against Pneumocystis.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.