Human immunodeficiency virus (HIV) causes HIV infection and attacks and destroys infection-fighting CD4 cells of the immune system. The absence of CD4 cells makes it challenging for the body to fight off infections and certain cancers. Without treatment, HIV proceeds to destroy the immune system and advance to acquired immunodeficiency syndrome (AIDS).
Due to the availability of better antiviral treatments, most people with HIV do not progress to AIDS. If untreated, it usually takes eight to ten years for HIV to advance to AIDS. At that point, the immune system is significantly damaged, and individuals are more likely to develop opportunistic infections or cancers. HIV medications can still help during this stage of the infection, though there is currently no cure for HIV/AIDS. Once an individual is infected by it, the body is unable to rid itself of the virus. However, there are medications called antiretroviral therapies (ART) that reduce the amount of HIV (viral load) in the body. Having less HIV in the body helps protect the immune system, and it helps prevent HIV infection from advancing to AIDS. ART also reduces the risk of HIV transmission to others. It is recommended that every HIV positive individual take ART and should start as soon as possible. It is generally recommended for the initial regimen to include at least three HIV medications from at least two different HIV drug classes.
The decision about an HIV regimen should be based on multiple factors. These include other disease states or conditions the HIV-infected individual has (eg, heart disease, pregnancy); potential side of effects of HIV medications; possible interactions between HIV medications or between HIV medications and other medications the person is taking; results of drug resistance testing and other testing indicating if any HIV medications would be ineffective against the person’s HIV; convenience of the regimen; and identifying any issues that would complicate adherence with the regimen.
The FDA has approved more than 30 different medications to treat HIV. They are grouped into drug classes based on how they attack the virus. Some of the approvals are two or more HIV medications combined into one pill.
- Nucleoside reverse transcriptase inhibitors (NRTIs) block reverse transcriptase, an enzyme HIV requires to make copies of itself. Drugs approved by the FDA in this class include Ziagen (abacavir sulfate), Emtriva (emtricitabine), Epivir (lamivudine), Viread (tenofovir disoproxil fumarate), and Retrovir (zidovudine)
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs) bind to and later alter reverse transcriptase, an enzyme HIV requires to make copies of itself. FDA-approved drugs that are part of this class include Pifeltro (doravirine), Sustiva (efavirenz), Intelence (etravirine), nevirapine ( Viramune, Viramune XR), and Edurant (rilpivirine)
- Protease inhibitors block HIV protease, which is an enzyme HIV needs to make copies of itself. Medications in this class that are currently approved by the FDA are Reyataz (atazanavir), Prezista (darunavir), Lexiva (fosamprenavir calcium), Norvir (ritonavir), Invirase (saquinavir mesylate), and Aptivus (tipranavir)
- Fusion inhibitors work by blocking HIV from entering the CD4 cells of the immune system. Currently, there is only one fusion inhibitor approved by the FDA, Fuzeon (enfuvirtide)
- CCR5 antagonists work by blocking CCR5 coreceptors that are found on certain immune cells that HIV needs to enter the cells. The only current FDA-approved CCR5 antagonist is Selzentry (maraviroc)
- Integrase inhibitors are a class of HIV medications that block HIV integrase, an enzyme that HIV requires in order to copy itself. Current FDA-approved drugs in this class are Tivicay (dolutegravir), Isentress and Isentress HD (raltegravir)
- Post attachment inhibitors work by blocking CD4 receptors on the surface of certain immune cells that HIV needs to enter the cells. Trogarzo (ibalizumab-uiyk) is currently the sole drug in this class approved by the FDA
- Pharmacokinetic enhancers are a drug class that is used in HIV treatment to increase the effectiveness of an HIV medication included in an HIV regimen. Tybost (cobicistat) is presently the only pharmacokinetic enhancer HIV drug approved by the FDA
There are also various HIV combination medications approved by the FDA that combine two or more HIV medications from one or more different drug classes. These therapies include:
In July 2020, the FDA approved a new drug HIV drug called Rukobia (fostemsavir). Rukobia is the first drug that is part of a new class of HIV medications called attachment inhibitors. An attachment inhibitor works by binding to the gp120 protein located on the outer surface of HIV. Consequently, this prevents HIV from entering CD4 cells. Rukobia is indicated in combination with other antiretrovirals for the treatment of HIV in adults who are heavily treatment-experienced with multidrug-resistant HIV and who have failed their current antiretroviral regimen due to resistance, intolerance, or safety considerations.
Pre-exposure prophylaxis (PrEP) is for individuals who are negative for HIV but are at risk of being exposed to it through sex or injection drug use. PrEP involves taking HIV medications every day to prevent HIV infection. If an individual on PrEP is exposed to HIV through sex or injection drug use, PrEP can stop HIV from establishing itself and spreading through the body. However, it is essential to note that if PrEP is not taken every day, the bloodstream may not contain enough medicine to block the virus. The CDC states that studies have shown that taking PrEP daily reduces the risk of getting HIV from sex by about 99% and from injection use by at least 74%. The risk of HIV transmission can be further reduced if the individual combines PrEP with other preventative measures (eg, use of condoms). Currently, Truvada (emtricitabine/tenofovir disoproxil fumarate) and Descovy (emtricitabine/tenofovir alafenamide) are the only two medications approved by the FDA for PrEP.
Post-exposure prophylaxis (PEP) is the use of antiretroviral drugs after possible exposure to HIV in order to prevent HIV from taking hold in the body. It should be started as soon as possible and must be started within 72 hours of possible exposure. Research has shown that PEP will most likely not be able to prevent HIV infection started more than 72 hours after exposure. It is not meant to replace regular use of other HIV prevention options such as consistent condom use or PrEP. PEP may be given if the person is HIV negative or if he or she does not know their HIV status, and within the previous 72 hours, the individual may have been exposed to HIV. Once PEP is started, it must be taken every day for 28 days. It is still necessary for the individual to continue to take precautions to prevent HIV transmission while taking PEP (eg, condom use, use of sterile needles). PEP typically consists of two to three antiretroviral HIV drugs.
Although there is currently no cure for HIV, there have been significant advancements made that, when accompanied by early intervention, HIV is treated today more as a chronic condition rather than a terminal illness. Hopefully, as advancements continue to occur, a cure emerges.