Comprehensive Nursing Pharmacology Q 187
Which of the following is true about protease inhibitors?
A. Work better when used alone.
B. Are the same as nucleoside analogs.
C. Affect replication of HIV at different stages than nucleoside analogs.
D. Have a high level of toxicity.
Correct Answer: C. Affect replication of HIV at different stages than nucleoside analogs.
Protease inhibitors cleave the viral polyprotein precursors that are essential for the maturation of infectious viruses. IV-1 protease causes cleavage of protein precursors generating new viral particles. Protease inhibitors disrupt this cleavage process, hence interrupting the production of new viral particles.
Option A: Protease inhibitors work best when used in combination with other drugs. Lopinavir/ritonavir, in combination with other standard ARV medications, has provided significant virological suppression and better immune outcomes in both treatment-naive and treatment-experienced patients.
Option B: Nucleosides interfere with the replication of HIV by inhibiting reverse transcriptase. The nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) were the first class of antiretroviral drugs to be approved by the FDA. NRTIs are taken as prodrugs and must be taken into the host cell and phosphorylated before they become active. Once inside the host cell, cellular kinases will activate the drug. The drug exerts its effect through its structure.
Option D: Because there is a small quantity of ritonavir in combination with lopinavir/ritonavir, there are few reports of ritonavir toxicity. However, there have been a few case reports suggesting retinal toxicity secondary to ritonavir. One such case showed an improvement after discontinuing ritonavir after 2 and 4 weeks.