Entry and Fusion Inhibitors

Question 1

Entry and Fusion Inhibitors

Answer 1

MVC- maraviroc
T20- enfuviritide

Other agents affect HIV life cycle after infection cell

There agents attempt to block HIV from infecting a cell

Question 2

Entry and Fusion Inhibitors MOA

Answer 2

Entrance involved a handshake between viral proteins and proteins on the host cell target

Enfuviritide binds to a viral
protein involved in fusion

Maraviroc targets a human protein (CCR5) that serves as a coreceptor for the virus

Only use is for HIV

Question 3

Entry and Fusion Inhibitors Adverse Effects

Answer 3

Dermatologic
Injection site reactions- pain, erythema, pruritis, nodule formation (essentially all patients on SC enfuviritide)

Hepatotoxicity
Maraviroc has black box warning based on case studies in healthy subjects in early clinical trials; the effect seems to be rare

Question 4

Entry and Fusion Inhibitors Important Facts

Answer 4

Since enfuviritide is a SC injection, reserved for difficult to treat multidrug resistant strains

Maraviroc only blocks one of two coreceptors
Will not be effective for viruses that use CXCR4 pathway for viral entry; a tropism test must be performed before beginning therapy
Trofile- name of the test used to determine the profile of its tropism
CCR5- yes
CXCR4- no

Maraviroc is a substrate of CYP450
Different dosing based on what interactors patient is on

These drugs mainly used in experienced patients