Repeated USMLE Questions Step 1- Pharmacology- 235

C- Ritonavir- It is a protease inhibitor used in the treatment of HIV/AIDS. Protease inhibitors work by inhibiting the activity of the HIV protease enzyme, which is essential for the replication of the virus. By blocking this enzyme, protease inhibitors prevent the virus from producing functional proteins necessary for its replication, thus helping to control the spread of the virus in the body. Etravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI). Lamivudine is a nucleoside reverse transcriptase inhibitor (NRTI). Tenofovir is also a nucleoside reverse transcriptase inhibitor (NRTI). Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI).

A- Decreased- Metoprolol, as a beta-blocker, reduces heart rate and myocardial contractility. Decreased contractility can lead to a reduction in the amount of blood ejected from the heart during systole, which ultimately lowers the cardiac ejection fraction.

C- Flumazenil- It is a benzodiazepine receptor antagonist that can reverse the effects of benzodiazepines, including midazolam, by competitively binding to the benzodiazepine receptors in the central nervous system. Therefore, if a paradoxical reaction occurs with midazolam, flumazenil can effectively reverse its effects.