What is the mechanism of action of atazanavir?
Atazanavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs.
Why is atazanavir combined with ritonavir?
Atazanavir/ritonavir is as effective as lopinavir/ritonavir, with a more favourable lipid profile and less gastrointestinal toxicity, in treatment-experienced HIV-1-infected patients. We compared these two combinations directly in treatment-naive patients.
Is atazanavir a protease inhibitor?
Atazanavir (formerly BMS-232632), an azapeptide protease inhibitor (PI), is a new human immunodeficiency virus (HIV) treatment that has recently received marketing approval from the FDA.
Is atazanavir a CYP3A4 inhibitor?
Atazanavir is a known substrate and inhibitor of CYP3A4 in vitro. Therefore, medications that are also metabolized by CYP3A4 may interact with atazanavir.
How does nucleoside reverse transcriptase inhibitors work?
Nucleoside Reverse Transcriptase Inhibitors (nucleoside analogues, NRTIs or nukes) When the HIV virus enters a healthy cell, it attempts to make copies of itself. It does this by using an enzyme called reverse transcriptase. The NRTIs work because they block that enzyme.
Who makes atazanavir?
Atazanavir – Bristol-Myers Squibb.
What is the mechanism of action of the nucleoside transcriptase inhibitors NRTIs )?
Mode of Action – NRTI Nucleoside Reverse Transcriptase Inhibitors (NRTIs) inhibit reverse transcription by causing chain termination after they have been incorporated into viral DNA. For these drugs to be active they need to be phosphorylated intracellularly.
What is the difference between nucleoside and nucleotide reverse transcriptase inhibitors?
The key difference between nucleoside and nucleotide reverse transcriptase inhibitors is that the nucleoside reverse transcriptase inhibitors need to undergo three-step phosphorylation to activate antiviral activity, while the nucleotide reverse transcriptase inhibitors do not need to undergo initial phosphorylation …
How does ritonavir inhibit protease?
Ritonavir’s inhibition of the cytochrome P-450 CYP3A4 enzyme reduces the metabolism of concomitantly administered protease inhibitors and changes their pharmacokinetic parameters, including area under the curve (AUC), maximum concentration (Cmax), minimum concentration (Cmin) and half-life (t1/2).
Why ritonavir is used as pharmacokinetic enhancer?
Ritonavir is an ideal pharmacologic enhancer because it inhibits two key stages of metabolism. First, it inhibits what is known as first-pass metabolism, which occurs during absorption.
What is TDF 3TC?
TDF and 3TC are nucleotide analogues that can inhibit both HIV and HBV DNA polymerases. There is higher risk to cause drug resistance in treating HBV or HIV infection with 3TC or TDF monotherapy than combination trerapy. Combination tharapy could decreases drug resistance.
How do NRTI nucleotide reverse transcriptase inhibitor medications work?
What is the mechanism of action of NRTI in antiretroviral therapy?
NRTIs interrupt the HIV replication cycle via competitive inhibition of HIV reverse transcriptase and termination of the DNA chain.
How is atazanavir synthesized?
The original synthesis of atazanavir. Another efficient and practical synthesis of atazanavir was developed by employing the diastereoselective reduction of ketomethylene aza-dipeptide (34.1.47) as the key and final step.
What is the bioavailability of nifedipine 10 mg?
Because of presystemic metabolism, the bioavailability is about 56% to 77%. After oral administration of 10 mg, the mean plasma concentration of nifedipine reaches maximum values of 160 +/- 49 micrograms/liter after 30 to 60 minutes.
How is nifedipine made from dimethyl ether?
Nifedipine, dimethyl ether 1,4-dihydro-2,6-dimethyl-4- (2′-nitrophenyl)-3,5-piridindicarboxylic acid (19.3.16), is synthesized by a Hantsch synthesis from two molecules of a β -dicarbonyl compound—methyl acetoacetate, using as the aldehyde component—2-nitrobenzaldehyde and ammonia.
How is nifedipine absorbed in the body?
Nifedipine is almost completely absorbed from the gastrointestinal tract as shown by plasma levels after sublingual, oral, and rectal administration. Because of presystemic metabolism, the bioavailability is about 56% to 77%.