Questions about Anti-HIV Agents – Antiviral Drugs

00:00 Okay, let's do a question.

00:03 The following is true about the NNRTI's, the Non-Nucleoside Reverse Transcriptase Inhibitors.

00:10 A) They bind to the same reverse transcriptase site as the nucleoside reverse transcriptase inhibitors.

00:19 B) They require phosphorylation to be activated.

00:23 C) They competitively inhibit nucleoside triphosphates.

00:28 D) There is cross resistance with the NRTI's.

00:33 And E) resistance is due to pol gene mutations that can occur quickly in monotherapy.

00:43 Great, you picked E.

00:44 So I mentioned before that the pol gene is responsible for point mutations that reduce the effectiveness of the non-nucleoside reverse transcriptase inhibitors.

00:55 This is the kind of question that is "fair game" on exams.

00:58 And I know that it looks like a hard question.

01:00 But if you remember the pol gene and env gene that we talked about, you'll do really well on these exams.

01:07 Now these are some really salient points that I want you to remember when you're studying.

01:12 The NNRTI's do not bind to the same sites as the NRTI's.

01:17 So A is not correct.

01:20 Number 2, while NRTI's require phosphorylation, the non-nucleoside agents don't.

01:27 Because they're not nucleosides.

01:29 Remember that nucleosides have to be phosphorylated.

01:32 You want guanine.

01:33 You want guanine triphosphate .

01:35 You want adenosine, you want adenosine triphosphate, right.

01:38 B is incorrect.

01:40 The nucleosides will completely and competitively inhibit nucleoside enzymes.

01:46 But non-nucleosides will not.

01:48 So therefore, the C choice was incorrect.

01:51 Now because they don't bind to that same site cross resistance is rare.

01:57 So therefore D was incorrect.

01:58 And the correct answer is E which is the pol mutation.