The client is admitted with pneumocytis carinii pneumonia. The nurse is aware that the physician will most likely order: A. Zidovudine (Ritrovir) B. Nivirapine (Viramune) C. Efavirenz (Sustiva) D. Sulfamethoxazole (Septra)

The client is admitted with pneumocystis carinii pneumonia. This is a type of pneumonia caused by an opportunistic fungus called Pneumocystis jirovecii. This type of pneumonia is most commonly seen in individuals with a weakened immune system, such as those with HIV/AIDS.

For each of the four medications listed, research their primary uses and indications. A. Zidovudine (Ritrovir): This is an antiretroviral medication primarily used in the treatment of HIV/AIDS. It is not a direct treatment for pneumonia. B. Nivirapine (Viramune): This is another antiretroviral medication also used in the treatment of HIV/AIDS. Again, it is not a direct treatment for pneumonia. C. Efavirenz (Sustiva): This medication is also an antiretroviral drug used to treat HIV/AIDS. It is not a first-line treatment for pneumonia. D. Sulfamethoxazole (Septra): This medication is an antibiotic that is effective against a wide range of bacterial and some fungal infections, including Pneumocystis jirovecii, the organism responsible for causing pneumocystis carinii pneumonia.

Based on the information gathered in step 2, we can rule out the antiretroviral medications (Zidovudine, Nivirapine, and Efavirenz) as they are not direct treatments for pneumonia. On the other hand, Sulfamethoxazole (Septra) is indicated for the treatment of pneumocystis carinii pneumonia, as it's effective against the causative organism.

Therefore, the nurse should be aware that the physician will most likely order Sulfamethoxazole (Septra) for the client with pneumocystis carinii pneumonia. The correct answer is D. Sulfamethoxazole (Septra).