At a glance
- Older individuals with HIV are dealing with the effects of age while on HAART and will endure unique side effects because of their age, comorbidities, and other prescribed medications.
Each category of drugs attempts to interrupt the life cycle of HIV at a different point, and when used together, there is an additive effect.
- The current standard for formulating a HAART regimen recommends the use of either a PI or an NNRTI in combination with two NRTIs.
Clinicians should also be aware of increased depression, which often develops in HIV-positive patients.
The introduction of highly active antiretroviral therapy (HAART) has transformed HIV infection from a rapidly progressive life-threatening illness to a chronic manageable condition. More and more persons are growing older with HIV infection.
The CDC estimates that more than 1 million people are living with HIV infection in the United States. Approximately 29% of those infected with HIV are older than age 50 years, and the number of older Americans with HIV infection is on the rise. In the next five years, the number of Americans older than age 50 years is projected to constitute 50% of those infected with HIV.1,2
The demographic shift in those affected by HIV is attributed to the aging of the baby boom generation and to medical advancements in antiretroviral therapy that are allowing HIV-infected adults to remain productive longer. Older individuals with HIV are dealing with the effects of age while on HAART and will endure unique side effects because of their age, comorbidities, and other prescribed medications.3,4 According to some data, up to 75% of deaths among HIV-infected adults taking antiretroviral medications are due to comorbidities, not AIDs-defining conditions.5
Comorbidities of the HIV-positive older adult
With age comes physiologic changes as well as susceptibility to certain chronic diseases. Approximately 80% of older adults have at least one chronic health condition, and 50% have two or more. Cardiovascular conditions (e.g., hypertension, coronary artery disease, and stroke) are the most common causes of morbidity and mortality in the older age group. Diabetes, hyperlipidemia, chronic obstructive pulmonary disease (COPD), and osteoporosis are also common in older adults. These conditions usually require prescription medications.
Older adults commonly take four to five prescription medications in addition to OTC medications daily.6 For many HIV-positive older adults, HAART is added to a regimen of other medications. Researchers are attempting to answer questions about how HAART will affect the aging adult, influence comorbid conditions and interact with other medications.
HAART medications and their mechanisms of action
The multidrug combinations of HAART can suppress the HIV viral load to undetectable levels and stop the destruction of CD4 T lymphocytes. There are six categories of HAART agents: nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), integrase strand transfer inhibitors (INSTIs), fusion inhibitors (FIs), and chemokine coreceptor 5 (CCR5) antagonists. The drugs in each category attempt to interrupt the life cycle of HIV at a different point, and when used together, there is an additive effect (Figure 1).7,8
Reverse transcriptase inhibitors (RTIs) block the activity of reverse transcriptase, an enzyme used by the virus to build new DNA from its RNA. PIs inhibit the activity of viral enzymes that cleave new proteins for final assembly into new HIV virions. Entry inhibitors, which include FIs and CCR5 antagonists, block entry of HIV into the cell membrane, preventing infection of uninfected cells.