Final answer:
Acyclovir sodium is the drug that a nurse should expect to administer to treat a painful blistering skin rash, likely herpes zoster, in a client with HIV. Acyclovir is used to manage symptoms of herpes, as it reduces the number and duration of viral episodes but is not a cure.
Step-by-step explanation:
When a client with human immunodeficiency virus (HIV) develops a painful blistering skin rash on the right lateral abdominal area, the nurse should expect to administer Acyclovir sodium to treat this condition. This is likely to be a case of herpes zoster (shingles), which frequently occurs in immunocompromised patients like those with HIV.
Antivirals such as acyclovir have been developed to treat conditions such as genital herpes (herpes simplex II) and are used to reduce the number and duration of episodes of active viral disease. This drug, while not curative, can make the symptoms of the disease more manageable, especially since viruses like herpes simplex and herpes zoster can remain latent in the nervous system for life.
The other medications listed are used for different types of infections or conditions and are not the drugs of choice for herpes viruses. Levofloxacin is an antibiotic, Fluconazole is an antifungal, and Esomeprazole is a proton pump inhibitor used for conditions like gastroesophageal reflux disease (GERD).