HIV | Warning Signs & Treatment Options

HAART

HIV Symptoms

To understand how HAART therapy works, we know that viruses are not as independent as bacteria. Neither can they replicate on their own, but rather “enslave” the cells and use their protein-forming machinery to produce new viruses. Viruses live to multiply and multiply to live. Antiviral agents work by disrupting this process of multiplication on various steps, and a combination of several antivirals that act on different stages tend to have the best effect.

HAART regimen consists of a group of different classes of drugs that include:

  • Nucleoside reverse transcriptase inhibitors (NRTI): They include drugs as Zidovudine and Lamivudine. They act by inhibiting the enzyme known as reverse transcriptase, which is essential in allowing the viral genetic material to be translated to a “language” that a cell can understand to use its protein-building machinery. Its side effects include a tendency to shift the body’s metabolism from aerobic to anaerobic metabolism, therefore causing lactic acidosis.
  • Non–nucleoside reverse transcriptase inhibitors (NNRTI): They include drugs as Nevirapine and Delavirdine. They work by a different mechanism than NRTI, although they eventually achieve the same effect. NRTI acts by competing with viral reverse transcriptase enzyme, while NNRTI acts by binding to the enzyme itself, rendering it non-functional. NNRTI are generally more potent than NRTI.
  • Protease Inhibitors: They include drugs as Atazanavir and Darunavir. They act by inhibiting the viral enzyme protease. The protease enzyme helps the viral particles mature by “cleaving” excess amino acids from the final protein product. Without such cleavage of proteins, viral particles become non-functional. Resistance may develop from first-generation protease inhibitors, necessitating the utilization of 2nd generation protease inhibitors as Tipranavir and Lopinavir. Common side effects with protease inhibitors include GIT upset as nausea, vomiting, diarrhea, and metabolic abnormalities such as insulin resistance and dyslipidemia.
  • Integrase inhibitors: They include drugs as Bictegravir and Dolutegravir. They act by inhibiting the enzyme responsible for integrating the viral genetic material into the cell’s one. Therefore they stop the operation of viral replication after the reverse transcriptase. Integrase inhibitors are generally well tolerated by patients with few side effects that are mostly confined to GIT side effects.
  • Fusion inhibitors: The only drug in use today of this class is Enfuvirtide. They act by inhibiting the virus from attacking the cell in the first place, and therefore they act on the first step of the cycle. They are now quite limited both in production and usage due to the increasing number of discovered antivirals with a better safety profile, better effects, and higher activity against resistant strains.
  • Chemokine receptor antagonists (CCR5 inhibitors): They are a new class of drugs approved by the FDA in 2007. The primary drug of this class is Maraviroc. It acts in a similar way to fusion inhibitors.

Previously, CD4 count was a strong determinant of whether a patient should take antiretroviral agents or not, this is no longer the case, and new guidelines suggest that treatment should be initiated regardless of the CD4 count.