Final answer:
To treat suspected PCP in an HIV-positive patient with a CD4 count <200, Bactrim is the first-line treatment, with atovaquone or pentamidine as alternatives. Close monitoring of CD4 counts is essential for guiding treatment adjustments.
Step-by-step explanation:
To treat suspected Pneumocystis pneumonia (PCP) in an HIV-positive patient with a CD4 count less than 200, it's crucial to initiate prompt antimicrobial therapy. The first-line treatment for PCP is usually a combination of sulfamethoxazole and trimethoprim, which is available under the brand name Bactrim. This can be administered either orally or intravenously depending on the severity of the infection. In cases where the patient cannot tolerate Bactrim or if the treatment fails, alternatives such as atovaquone or pentamidine are used.
For an HIV-positive patient with a low CD4 count, close monitoring of the immune status using flow cytometry is recommended to adjust the treatment as necessary. P. jirovecii, the causative agent of PCP, is a fungus that causes illness primarily in individuals with weakened immune systems, and early intervention is imperative to prevent complications such as collapsed lung and to reduce mortality.