AIDS is still not curable, but thanks to a wide variety of drugs, it can now usually be treated well. The drugs prevent the HI virus, which triggers the immune deficiency, from multiplying. By taking the medication regularly, the concentration of the viruses can be kept so low that the disease itself is hardly noticeable, if at all. However, the treatment itself can cause side effects. Learn more about the different AIDS medications, possible side effects of therapy, and the cost of treatment here.
HIV positive and AIDS – what is the difference?
HIV positive and AIDS are often used interchangeably – but this is not entirely correct. HIV positive simply means that there is an infection with the HI virus. Only when the disease breaks out is AIDS spoken of. The abbreviation stands for the English term “Acquired Immune Deficiency Syndrome”. Years can pass between infection and the onset of the disease – in about 50 percent of those affected, it takes 10 years or more for the disease to break out.
When is treatment necessary?
Treatment for HIV is not usually necessary from the start. Regular checks can determine exactly how many HI viruses are in the body and how strongly the immune system has already been attacked by the virus. For a while, the body usually copes well with the virus itself. However, if the doctor determines during a check-up that the virus has multiplied considerably, treatment with medication should be started. Exactly when is the optimal start for therapy is still controversial among experts.
Multiplication of the HI virus
Like other viruses, HIV requires host cells in order to replicate. Host cells include the CD4 helper cells of the immune system. The HI virus attaches to the host cells and penetrates them. It introduces its own DNA into the cell so that it no longer produces defense cells but viruses. If the infected defense cell dies, the HI virus looks for a new host cell. This weakens the immune system more and more, and in the worst case, the immune system can collapse. Due to the weakened defense system, even pathogens that cause little or no harm in healthy individuals can be life-threatening to AIDS patients.
Medications for AIDS
Several drugs are available to treat the HIV virus, but they are usually used in combination. AIDS drugs are classified into different groups depending on the points in the multiplication process at which they intervene. In general, the following five groups are distinguished:
- Entry inhibitors
- Nucleoside reverse transcriptase inhibitors (NRTI).
- Non-nucleoside reverse transcriptase inhibitors (NNRTI).
- Integrase inhibitors
- Protease inhibitors
Treatment with the AIDS drugs decreases the number of HI viruses in the body and the immune system can recover. Ideally, the drugs completely prevent the formation of new HI viruses. If the number of HI viruses in the body decreases, the risk of infection also decreases. This factor plays an important role in preventing mother-to-child transmission, among other things.
Entry inhibitors
Entry inhibitors ensure that the HI viruses cannot penetrate the host cells in the first place. Thus, unlike the other AIDS drugs, they act on the surface of the cell rather than inside it. A subgroup of entry inhibitors – the so-called fusion inhibitors – prevent the viral envelope from fusing with the cell membrane of the host cell. In addition to fusion inhibitors, there are other entry inhibitors (attachment inhibitors), although these are currently still in the research phase. They prevent the HI viruses from docking at the cell surface of the host cells in the first place. This is done by artificially occupying the corresponding receptors with the drug. Active ingredients: enfuvirtide, maraviroc
Nucleoside reverse transcriptase inhibitors (NRTIs).
In order for HIV to incorporate its genetic information into that of the host cell, it must first modify it: It must convert its genetic information from single-stranded RNA to double-stranded DNA. This process requires a specific enzyme called reverse transcriptase.By taking NRTI, a building block is introduced into the host cells that resembles the genetic building blocks of the virus. If this building block is incorporated into the genetic information by the enzyme, the DNA chain can subsequently no longer be extended. As a result, the activity of the enzyme is inhibited and no further viral DNA can be formed. Active ingredients: zidovudine, lamivudine, abacavir, didanosine, stavudine, emtricitabine
Non-nucleoside reverse transcriptase inhibitors (NNRTIs).
NNRTIs, like NRTIs, target the enzyme “reverse transcriptase.” Unlike NRTIs, however, they do not introduce the wrong building blocks into the viral genetic information. Instead, NNRTIs directly inhibit the action of the enzyme: they attach themselves to the “reverse transcriptase” and prevent it from reassembling the genetic information of the HI virus. Active ingredients: Nevirapine, efavirenz
Integrase inhibitors
Once the virus’ genetic information has been able to be transcribed by “reverse transcriptase,” the next step is to introduce it into the nucleus of the host cell. This is where integrase inhibitors come in: They prevent the genetic information from being incorporated into the host cell and thus prevent further spread of the virus. Active ingredients: raltegravir, elvitegravir
Protease inhibitors (PI).
If the genetic information of the HI virus has already been introduced into the cell, new building blocks for further viruses are produced there and subsequently assembled. The individual building blocks are initially still connected to each other. In order for them to be assembled correctly, they must first be separated by the enzyme protease. Protease inhibitors inhibit the action of this enzyme. As a result, no further viruses can be produced and the virus can no longer reproduce. Active ingredients: forsamprenavir, indinavir, nelfinavir, ritonavir
