Haart Medication for HIV Patients

HIV is a difficult virus to treat and no vaccine has been developed. One approach is to combine two or three treatments to form a cocktail of drugs that have a greater chance of slowing the spread of HIV around the body and the subsequent deterioration of the patient. This is known as highly active antiretroviral therapy (HAART).

HIV

• HIV is a spherical virus containing two single strands of ribonucleic acid, RNA. It is transmitted between people through the exchange of bodily fluid such as during sex. HIV fuses with body cells responsible for immunity known as CD4 T cells. Upon fusion, HIV RNA is mixed with the DNA of CD4 T body cells. This allows HIV to replicate itself using the body's own replication machinery forming virions. Virions are released, infecting the body and weakening its immune system.

The Problem with HIV

• Once HIV infects the CD4 T cell, the viral RNA integrates itself into the DNA of infected cells thus becoming part of the body it has infected. This allows HIV to escape detection by the body's immune system. Initially the body develops antibodies to fight HIV but a further problem with HIV is that it mutates forming a different structure. By the time the body produces antibodies, HIV has already mutated so the antibodies are ineffective.

HAART

• There is no vaccine for HIV but antiretroviral medications slow the development of HIV infection. It is advised to take two or more to have maximum effect against HIV. This combination is known as highly active antiretroviral therapy (HAART).

Classes of Drugs

• HIV contains RNA and other proteins used to replicate. For example, HIV contains the protein reverse transcriptase. Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs) are a class of drugs used to immobilize reverse transcriptase thus preventing HIV from replicating.

  When HIV replicates it creates copies of its structure using components called nucleotides. A class of drug known as Nucleoside Reverse Transcriptase Inhibitors (NRTIs) provides building components used by HIV instead of nucleotides to replicate. This halts replication.

  HIV needs to make new proteins to replicate. It uses a protein known as HIV-1 protease to complete the final step of making proteins. Protease Inhibitors (PIs) are a class of drug which prevents HIV-1 protease from working and so viral proteins are not made.

  When HIV finishes replicating itself, it creates virions that circulate the body infecting other cells. Entry/Fusion Inhibitors are another class of drug which prevents virions from infecting other cells. This slows the progression of HIV infection.

  One of the proteins made by HIV is known as integrase. It facilitates the entry of virions into other body cells when HIV is circulating the system. A class of drug known as Integrase Inhibitors prevents integrase from working, halting the progress of HIV infecting other body cells.

  In November 2009, the World Health Organization advised first line treatment for HIV should be two nucleoside reverse transcriptase inhibitors and one non-nucleoside reverse transcriptase inhibitor, known as a triple cocktail. This is based upon evidence suggesting this combination provides the greatest efficacy with the fewest side effects.

  When this combination of drugs is ineffective at slowing the spread of HIV in the body, the doctor will change the treatment to a more expensive second line of drugs. A different two nucleoside reverse transcriptase inhibitors will be prescribed along with a protease inhibitor. If this treatment also fails to work the doctor will consider other treatment options such as integrase inhibitors.

Fixed-Dose Combination

• Fixed dose combinations mix the ingredients of two classes of antiretroviral medications forming a single pill. This reduces the number of pills a patient has to take.