The management of patients with HIV/AIDS is constantly evolving as new therapies emerge. HIV is now viewed as a chronic disease much like diabetes or heart failure. Optimal treatment requires a great deal of education, planning, monitoring, resources, and effort. Key components of management include:• Preventing recurrent infection. Patients can be subsequently infected with different HIV strains as well as other pathogens such as tuberculosis (TB), toxoplasmosis, cytomegalovirus (CMV), and hepatitis C.
• Treating the underlying immune deficiency with Highly Active antiRetroviral Therapy (HAART)
• Preventing and treating opportunistic infections such as Pneumocystis pneumonia
• Treating other manifestations of AIDS such as cancer, encephalopathy, and wasting
• Treating co-morbid conditions such as depression and substance abuse
• Detecting and treating complications of these therapies
Managing patients with HIV/AIDS also involves critical decisions regarding:
• Determining the best time to initiate/alter treatment
• Monitoring the response to therapy by assessing clinical status, CD4 counts and viral loads
• Preventing and recognizing interactions between/among the many drugs used in treatment
The Food and Drug Administration has approved drugs for the treatment of HIV infection. The first group of drugs is called nucleoside reverse transcriptase inhibitors (NRTI). They block reverse transcription and prevent the formation of DNA, thus inhibiting the virus' ability to reproduce itself. Included in this group are as zidovudine (formally known as AZT), ddC (zalcitabine), ddI (dideoxyinosine), d4T (stavudine), 3TC (lamivudine) and nevaripine. Used alone (monotherapy), these drugs may slow the spread of HIV in the body and delay the onset of opportunistic infections. However, because HIV rapidly develops resistance to each of the NRTIs, monotherapy is no longer recommended. NRTIs are now used in combination with other classes of drugs.
Non-nucleoside reverse transcriptase inhibitors (NNRTI) are a second class of drugs active against HIV. They have a different chemical composition than NRTIs but also interfere with the process of reverse transcription. Nevirapine and efavirenz are examples of NNRTIs.
A third class of drugs targeting the process of reverse transcription has been developed. Tenofovir, a nucleotide, is the first one to come to market. Protease inhibitors (PI) interrupt virus replication at a later stage in its life cycle. Specifically, they block the activity of the protease enzyme. PIs include ritonavir (Norvir), saquinivir (Invirase), and indinavir (Crixivan).
Enfurvitide is a fusion inhibitor. This drug prevents HIV from entering human cells.
The use of these drugs is extremely complex. In general, they are used in combinations shown to be active against HIV. HAART denotes the use of combination therapy. Adherence to therapy is critical in order to minimize the development of resistance.
