Antivirals Flashcards
1 step - Binds to CD4 receptor of CD4 + T cells
GP120
2 step - binds to CCR5/CXCR4 co receptor of T cells
GP120
3 step - binds to T cell membrane and causes fusion of virus and T cell followed by viral genome entry into the cell
GP41
Codes for p24 and p17 (core protein)
Gag
Reverse transcriptase, integrate, protease
Pol
Gp120, gp41 (entry)
Env
Competive inhibition of HIV 1 reverse transcriptase
NRTIs
Absent hydroxyl group at 3’
Inhibition of 3’-5’ PDE bond formation
Incorporation into growing viral DNA strand causes premature chain termination
Nucleosides needs phosphorylation by cellular enzymes to be activated
Mitochondrial toxicity
NRTIs
Less toxic
ADR - headache, nausea, neutropenia
Cytidine base
Lamivudine
No serious A/E: low affinity for human DNA polymerase
Fanconi like syndrome
Adenosine base
Tenofovir
Used during pregnancy and breastfeeding to reduce vertical infection Tx and prophylaxis of HIV Combined with NNRTI and PI Can cause anemia Tymidine base
Zidovudine
ADR acute pancreatitis and peripheral neuropathy
Tymidine base
Stavudine
ADR: acute pancreatitis, optic neuritis, diarrhea, peripheral neuropathy
Adenosine base
Didanosine
Hypersensitivity associated with HLA-B 57:01 allele
May cause delayed type 4 hypersensitivity ran
Guanosine base
Abacravir
Less toxic
SE: hyperpigmentation of palms and soles
Cytidine base
Emitricitabine
Bind directly and not phosphorylated by intracellular enzymes - resulting in allosteric inhibition preventing replication of DNA
Bind directly and allosteric inhibition of HIV reverse transcriptase
NNRTIs
SE: insomnia and nightmares, rash is freq. with all drugs - 1st 4wks Rx
NNRTIs - especially efavirenz
NNRTIs
Nevarapine
Elfavirenz
Delaviridine
Etravirine
Rilpivirine
Inhibit the aspartate protease protease in HIV
Inhibit cytochrome p450
Protease inhibitors “Navir”
Codes for production of HIV enzymes, resistance mechanism will be developed in varying genes
POL gene
SE: hyperglycemia in diabetes due to insulin resistance, lipodystrophy, paraesthesia, rash at therapeutic [ ]
Protease inhibitors
Need to process gag and pol polyproteins into mature HIV components
Aspartate protease
Protease inhibitor that may cause nephrolithiasis
Indinavir
Protease inhibitor has greatest cytochrome p450 inhibitory effect and boosts concentration of other protease inhibitors
Ritonavir
Protease inhibitor - least toxic and easily develops resistance
Saquinavir
Protease inhibitor causing indirect hyperbilirubinemia
Atazanavir