Old NBME question clarification - Enzyme inhibition

[sahell]

Pt is treated for PUD with drug X. Later he is treated with diazepam for anxiety and falls asleep more quickly and for a longer duration. What is drug X?

Cimetidine or Omeprazole? I ruled out other options but these 2 both fit. I'd prefer omeprazole to treat the ulcer.

Research didn't help:
ncbi . nlm . nih . gov/pubmed/2276389 (I can't post links yet)

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[Surgeria]

cimetidine inhibiting p450 and increasing the dosage of diazepam? - this could lead to overdose with diazepam and longer sleep duration? perhaps ...

 

[sahell]

I agree but Omeprazole is an inhibitor of p450 as well. My kaplan pharm prof puts her money on Cimetiidne because it's a stronger inhibitor but a USMLE Rx question I just did seems to suggest Omeprazole (similar vignette but GED instead of PUD).

 

[Surgeria]

I agree but Omeprazole is an inhibitor of p450 as well. My kaplan pharm prof puts her money on Cimetiidne because it's a stronger inhibitor but a USMLE Rx question I just did seems to suggest Omeprazole (similar vignette but GED instead of PUD).

I don't think that you will encounter that type of question on the real deal of that kind of similarity, they will of course throw on you many many questions where you will need to guess between two similar answers, but guessing between Cimetidine and Omeprazole is kind of top of pickiness ... Omeprazole is superior to than cimetidine in treatment, but cimetidine is stronger inhibitor. I have never heared about omperazole being a p450 inhibitor. Let's say if they told you that the patient had a refractory peptic ulcer disease, then maybe we need to think about omperazole? anyways there would be something that will turn us on to omperazole, because cimetidine is well known p450 inhibitor on boards, not in real life, who ever will prescribe cimetidine in 21 st century ? ...

 

[Rahas]

Diazepam is a basic drug and PPIs decrease gastric acidity to a greater extent, so the reason might be that they increase absorption more.

 

[sahell]

I don't think that you will encounter that type of question on the real deal of that kind of similarity, they will of course throw on you many many questions where you will need to guess between two similar answers, but guessing between Cimetidine and Omeprazole is kind of top of pickiness ... Omeprazole is superior to than cimetidine in treatment, but cimetidine is stronger inhibitor. I have never heared about omperazole being a p450 inhibitor. Let's say if they told you that the patient had a refractory peptic ulcer disease, then maybe we need to think about omperazole? anyways there would be something that will turn us on to omperazole, because cimetidine is well known p450 inhibitor on boards, not in real life, who ever will prescribe cimetidine in 21 st century ? ...

I hope you're right. This was on an old NBME so it was STEP1 material at some point. Kaplan says omeprazole is an inhibitor. Between FA, Kaplan and UW, I now have a massive list of inhibitors that could possibly show up.