Agents of HIV/ AIDS

Question 1

HIV Agents

Answer 1

• Nonnucleoside Reverse Transcriptase Inhibitors (NNRTI)
• Nucleoside Reverse Transcriptase Inhibitors (NRTI)
• Protease Inhibitors

Question 2

Types of NRTI

Answer 2

* Zidovudine (Azidothymidine, AZT)
* Didanosine

NRTI must undergo phosphorylation to become active in the body

Question 3

Types of NNRTI

Answer 3

• **Nevirapine (Viramune)
• Delavirfine**

NNRTI are already chemically active

Question 4

NRTI MOA

Answer 4

Converted to their corresponding triphosphate derivatives which have a gigh affinity for reverse tanscrpitase;
NRTI are nucleoside analogs.
Competitively inhibit reverse transcriptase and terminate DNA chain elongation

Question 4

NRTI MOA

Answer 4

Converted to their corresponding triphosphate derivatives which have a high affinity for reverse tanscrpitase;
NRTI are nucleoside analogs.
Competitively inhibit reverse transcriptase and terminate DNA chain elongation

Question 5

NNRTI MOA

Answer 5

Binds directly to HIV reverse transcriptase, blocking both RNA and DNA dependent DNA polymerase activities

Question 6

Pharmacokinetics NRTI

Answer 6

Well absorbed when given orally
T 1/2 varies from 1 to 4 hrs; all except abacavir are excreted in urine

Question 7

Pharmacokinetics NNRTI

Answer 7

• Delavidine: Rapidly absorbed from GIT; extensively metabolized by cytochrom P459 system in the liver; excreted via urine

* Nevirapine: Rapid GI absorption; metabolized by cytochrom P450 system in the liver; excreted via urine; half life of 45hrs

Question 8

NRTI Adverse Effects

Answer 8

bone marrow suppression, headache, nausea, mylagia, fatigue & insomnia, myopathy, neurotoxicity

Question 9

NNRTI

Answer 9

headache, dizziness, drowsiness, nightmare, confusion, vomiting, diarrhea, rash

Question 10

Drug Interactions

Answer 10

NRTI : Didanosine can cause reduced effect in antibiotics and antifungals

NNRTI: life threatening if combined with antiarrhythmics, antitubercolosis, calcium channel blockers, quinidine, indinavir, dapsone, warfarin, saquinavir

Question 11

Protease Inhibitors

Answer 11

• Indinavir
• Nelfinavir
• Ritonavir
• Saquinavir

All used in combination for HIV

Question 12

Protease Inhibitors MOA

Answer 12

Blocks protease activity in HIV virus. Protease is essential for the maturation of an infectious virus; without it HIV PARTICLES REMAIN IMMATURE AND NONINFECTIVE.
unable to fuse and inject cells.

Question 13

Protease Inhibitors Pharmacokinetics

Answer 13

Rapidly absorbed in GIT, netabolized in the liver and excreted in urine & feces

Question 14

Adverse Effects of Protease Inhibitors

Answer 14

nausea, vomiting, diarrhea, anorexia, change in liver function, rash, pruritus and potentially fatal steven-johnson syndrome