Once the cell count is decreased then patient will develop the susceptibility against various infections which will worsen the prognosis of the patient. It is the secondary infections because of the decreased or suppressed immune response the patient faces risk of. These infections could be life threatening also. Those infections which occur in the immunocompromised state of the body are also known as opportunistic infections.
Patients needs to be started on antiretroviral therapy before the CD4 count drops to less than 200/μL but it is recommended to start therapy in patients with CD4 counts above 500/μL who do not have clinical evidence of immune deficiency.
Prophylactic treatment with trimethoprim-sulfamethaxazole decreases the risk of Pneumocystis pneumonia and should be started when the CD4+ T-cell count drops to below 200/µL. Alternative treatment includes dapsone but the patient should be screened for glucose-6-phosphatase dehydrogenase. Trimethoprim-sulfamethaxazole also prevents toxoplasmosis and is given when the CD4+ T-cell count drops to below 100/µL. CD4+ counts below 50/µL carries the risk for Mycobacterium avium complex infection so and Azithromycin or clarythromycin is advised prophylactically weekly.
Fluconazole is advised in patients with CD4+ T-cell counts under 50/µL prophylactically as they are at increased risk for candidal or cryptococcal infections. Ganciclovir provides effective protection against cytomegalovirus infection in patients with advanced disease. Ganciclovir also reduces invasive disease.
Effective antiretroviral therapy important as it improves prognosis and prevents opportunistic infections. Instead of a single drug at a time, therapy should involve combinations of drugs like combining two nucleoside-analogue reverse-transcriptase inhibitors with either a protease inhibitor or a non-nucleoside–analogue reverse-transcriptase inhibitor.
Various classes of drugs are available among them again many drugs are available and are used widely in combination to treat the patient at various stages -