Antiretroviral medication

Antiretroviral Medication

Antiretroviral medications are drugs used to treat infections caused by retroviruses, primarily HIV. These medications are a cornerstone in the management of HIV/AIDS, helping to control the virus, improve quality of life, and reduce the risk of transmission.

History

The development of antiretroviral therapy (ART) began in the late 20th century, with the first drug, AZT, approved in 1987. Since then, numerous other drugs have been developed, leading to the current standard of care, which involves combination therapy to prevent resistance and improve efficacy.

Classes of Antiretroviral Drugs

Antiretroviral medications are categorized into several classes based on their mechanism of action:

• Nucleoside Reverse Transcriptase Inhibitors (NRTIs): These drugs mimic the natural nucleosides used by the virus to synthesize DNA, thereby inhibiting the reverse transcriptase enzyme. Examples include AZT, 3TC, and FTC.

• Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs): These drugs bind directly to the reverse transcriptase enzyme, causing a conformational change that inhibits its activity. Examples include Efavirenz and Nevirapine.

• Protease Inhibitors (PIs): These drugs inhibit the protease enzyme, which is crucial for the maturation of infectious viral particles. Examples include Ritonavir and Lopinavir.

• Integrase Inhibitors: These drugs block the integrase enzyme, preventing the integration of viral DNA into the host genome. Examples include Raltegravir and Dolutegravir.

• Entry Inhibitors: These drugs prevent the virus from entering host cells. Examples include Maraviroc, which blocks the CCR5 co-receptor, and Enfuvirtide, which inhibits fusion.

Mechanism of Action

Antiretroviral drugs work by targeting different stages of the HIV life cycle. By inhibiting key enzymes or blocking entry into cells, these drugs reduce viral replication and lower the viral load in the body. This helps to preserve immune function and prevent the progression to AIDS.

Treatment Regimens

The standard treatment for HIV involves a combination of at least three antiretroviral drugs from at least two different classes. This approach, known as Highly Active Antiretroviral Therapy (HAART), is designed to maximize viral suppression and minimize the risk of drug resistance.

Side Effects

While antiretroviral therapy is generally well-tolerated, it can cause side effects, which vary depending on the specific drugs used. Common side effects include nausea, fatigue, and diarrhea. Long-term use can lead to metabolic changes, such as lipodystrophy and insulin resistance.

Resistance

HIV can develop resistance to antiretroviral drugs, particularly if adherence to the treatment regimen is poor. Resistance testing is often performed to guide therapy adjustments and ensure the continued effectiveness of treatment.

Also see

• HIV/AIDS
• Zidovudine
• Protease Inhibitors
• Reverse Transcriptase Inhibitors
• Integrase Inhibitors