HSV treatment discrepancy

[Handinhand]

Hey all, just came across a discrepancy between first aid and UWorld and I would like some clarification.

UWorld questions is a young male who presents with a vesicular penile lesion, tzank smear confirms HSV. It then asks which pharmacological regimen has the best chance to prevent re-occurrence.

The two answers that even remotely make sense are acyclovir during the outbreak, or valacyclovir following the outbreak. I chose acyclovir, as first aid specifically states that the viral DNA polymerase inhibitors have no effect on latent forms of HSV and VZV. UWorld of course says that other answer is correct, so now I am confused.

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[Missorleans]

Hey all, just came across a discrepancy between first aid and UWorld and I would like some clarification.

UWorld questions is a young male who presents with a vesicular penile lesion, tzank smear confirms HSV. It then asks which pharmacological regimen has the best chance to prevent re-occurrence.

The two answers that even remotely make sense are acyclovir during the outbreak, or valacyclovir following the outbreak. I chose acyclovir, as first aid specifically states that the viral DNA polymerase inhibitors have no effect on latent forms of HSV and VZV. UWorld of course says that other answer is correct, so now I am confused.

I don't understand your reasoning, acyclovir and valacyclovir have basically the same MOA...
They wanted you to pick valacyclovir following the outbreak as prophylaxis against future outbreaks. Giving acyclovir during the outbreak is going to do nothing to prevent recurrence.

 

[Apoplexy__]

Hey all, just came across a discrepancy between first aid and UWorld and I would like some clarification.

UWorld questions is a young male who presents with a vesicular penile lesion, tzank smear confirms HSV. It then asks which pharmacological regimen has the best chance to prevent re-occurrence.

The two answers that even remotely make sense are acyclovir during the outbreak, or valacyclovir following the outbreak. I chose acyclovir, as first aid specifically states that the viral DNA polymerase inhibitors have no effect on latent forms of HSV and VZV. UWorld of course says that other answer is correct, so now I am confused.

QID 1550 right?

This question is less about valacyclovir vs. acyclovir and more about acute Tx during episode vs. prolonged Tx after episode being better for prophylaxis. Valacyclovir is nothing more than a more bioavailable form of acyclovir anyway.

This question was weird and maybe poorly written but all they wanted you to know was that you can minimize HSV recurrence by taking a daily anti-viral. This is as opposed to the other treatment plan of acyclovir, which is an acute dose to minimize length of an attack.

It doesn't necessarily contradict what FA says, since the daily acyclovir will block viral replication when it decides to amp up again. All FA is trying to let you know is that you can't eradicate HSV from your body nor can you ensure it will be permanently inactive through long-term antiviral therapy.

 

[Handinhand]

I don't understand your reasoning, acyclovir and valacyclovir have basically the same MOA...
They wanted you to pick valacyclovir following the outbreak as prophylaxis against future outbreaks. Giving acyclovir during the outbreak is going to do nothing to prevent recurrence.

Read what I wrote. First aid writes that DNA polymerase inhibitors aren't active against latent virus, which is why I didn't pick valacyclovir, because it's being given after an active infection (a latent stage you might say). I'm fully aware of their identical action.

I guess I understand what they were asking in the question, they just wrote it in a terrible way. If the drug has no action against latent virus, then it really doesn't prevent re-occurance, it just knocks down the active infection before you actually become symptomatic. Those are two different things in my mind, and is why I chose the acyclovir answer.

 

[Apoplexy__]

it really doesn't prevent re-occurance, it just knocks down the active infection before you actually become symptomatic.

As long as you get the take-away that daily acyclovir prevents re-occurance by knocking down the active infection before you actually become symptomatic, that's all that matters.

 

[GadRads]

The answer could have been DAILY valcyclovir. They have to take the drug (acyclovir, famciclovir, valcyclovir) almost everyday to decrease the odds of viral replication.