What is Atazanavir & Ritonavir Tablets ?
- Atazanavir:
- Atazanavir belongs to a class of drugs known as protease inhibitors. These medications work by blocking an enzyme called HIV protease, which is necessary for the virus to replicate and produce new copies of itself.
- Atazanavir is typically taken in combination with other antiretroviral drugs to form a comprehensive treatment regimen.
- Ritonavir:
- Ritonavir is also a protease inhibitor, but it is often used in combination with other protease inhibitors, like Atazanavir, to enhance their effectiveness. When used in this way, it helps to increase the levels of Atazanavir in the body, allowing for better control of the virus.
- Ritonavir itself is not typically used as a primary protease inhibitor for HIV treatment due to its lower effectiveness when used alone.
Atazanavir & Ritonavir Tablets Use
- Atazanavir (brand name: Reyataz): This medication is an HIV protease inhibitor. It works by blocking the activity of a protein called protease, which is needed for the virus to replicate. This helps to slow down the progression of HIV in the body.
- Ritonavir (brand name: Norvir): Ritonavir is also a protease inhibitor, but it is primarily used as a “booster” medication. When combined with other protease inhibitors, such as Atazanavir, it increases the levels of the primary drug in the blood, allowing for a lower dose to be effective. This can help improve the effectiveness of the treatment and reduce the likelihood of developing drug resistance.
Atazanavir & Ritonavir Tablets – Mechanism of Action and Pharmacology
- Atazanavir:
- Mechanism of Action: Atazanavir is classified as a protease inhibitor. HIV replicates by producing new viral particles through a process that involves the cutting (cleavage) of a large viral protein into smaller functional proteins by an enzyme called HIV protease. Protease inhibitors like atazanavir work by inhibiting the activity of this enzyme. By doing so, they prevent the production of mature, infectious viral particles.
- Pharmacology: Atazanavir is orally administered and gets absorbed in the gastrointestinal tract. It’s metabolized mainly in the liver by enzymes of the cytochrome P450 system, specifically CYP3A4. This means it can interact with other drugs that are metabolized by the same pathway. It’s eliminated mainly through the feces, with a smaller portion excreted in the urine.
- Ritonavir:
- Mechanism of Action: Ritonavir is also a protease inhibitor, similar to atazanavir. However, it is often used in combination therapy not for its direct antiviral effect, but for its ability to inhibit the enzyme CYP3A4 in the liver. This inhibition slows down the metabolism of other protease inhibitors, including atazanavir, allowing them to remain in the body at higher concentrations and increasing their effectiveness.
- Pharmacology: Ritonavir is also orally administered and gets absorbed in the gastrointestinal tract. It’s extensively metabolized in the liver, primarily by CYP3A4. Due to its inhibitory effect on this enzyme, it leads to increased levels of other protease inhibitors that are metabolized by the same pathway. Ritonavir is primarily eliminated through the feces.
Atazanavir & Ritonavir Tablets – Side-effects
- Nausea and Vomiting: These symptoms may occur, especially when first starting the medication. Taking atazanavir with food can help alleviate this.
- Jaundice (Yellowing of the Skin and Eyes): Atazanavir can occasionally affect the liver, leading to elevated levels of bilirubin in the blood, which can cause jaundice.
- Elevated Bilirubin Levels: As mentioned, atazanavir can cause an increase in bilirubin levels in the blood. This is usually not associated with liver damage.
