Which of the following agents is indicated in a 25 year old female is diagnosed with genital herpes simplex virus infection?

Correct Answer: B

Rationale: The correct answer is B: Valacyclovir. Valacyclovir is a commonly prescribed antiviral medication used to treat genital herpes simplex virus infections. Firstly, it is a nucleoside analog that inhibits viral DNA replication, helping to reduce symptoms and prevent outbreaks. Additionally, Valacyclovir is well-tolerated and effective in managing herpes infections in young adults. Choice A, Amantadine, is an antiviral primarily used for treating influenza A virus infections and is not effective against herpes simplex viruses. Choice C, Lamivudine, is an antiretroviral medication used to treat HIV and hepatitis B infections, not herpes simplex virus infections. Choice D, Zanamivir, is also an antiviral used for treating influenza infections and is not indicated for genital herpes simplex virus infections.

Correct Answer: A

Rationale: Rationale: 1. Ganciclovir is the preferred antiviral for CMV infections due to its effectiveness against CMV. 2. It works by inhibiting viral DNA polymerase, stopping viral replication. 3. Indinavir is a protease inhibitor used for HIV, not CMV. 4. Amantadine is used for influenza A virus, not CMV. 5. Foscarnet is an alternative for CMV if ganciclovir is not tolerated.

Correct Answer: A

Rationale: The correct answer is A: Benzathine penicillin. Benzathine penicillin has the longest duration of action among the choices because it is formulated as a salt that releases the active drug slowly over an extended period. The benzathine salt forms a depot at the injection site, leading to a sustained release of penicillin into the bloodstream. This results in a prolonged therapeutic effect and less frequent dosing compared to other penicillin preparations. Summary: - Choice B: Sodium penicillin has a shorter duration of action as it gets rapidly absorbed and eliminated from the body. - Choice C: Potassium penicillin is not a standard form of penicillin and does not exist as a distinct preparation. - Choice D: Procaine penicillin has an intermediate duration of action compared to benzathine penicillin due to the addition of procaine for local anesthesia, but it is not as long-acting.

Correct Answer: D

Rationale: The correct answer is D because both statements (A and B) are accurate. A: Metronidazole is a first-line drug for amoebic dysentery and liver abscess due to its efficacy against Entamoeba histolytica. B: Metronidazole is a prodrug that gets activated to form nitro intermediates, which bind DNA and disrupt anaerobic microbial replication. Therefore, option D is correct as both A and B provide accurate information about metronidazole. Option C is incorrect as metronidazole is not specifically targeted to eradicating amoebic cysts from the colon.

Correct Answer: D

Rationale: The correct answer is D: Escherichia coli. E. coli is notorious for developing antimicrobial resistance rapidly due to its ability to acquire resistance genes through plasmid exchange and mutation. This bacterium is commonly found in the gut of humans and animals, leading to frequent exposure to antibiotics. On the other hand, choices A, B, and C are less likely to develop resistance as rapidly as E. coli due to their lower frequency of exposure to antibiotics and differences in genetic makeup. Streptococcus pyogenes is susceptible to penicillin, Meningococcus has shown susceptibility to several antibiotics, and Treponema pallidum has limited exposure to antibiotics due to its unique nature as the causative agent of syphilis.