Hi guys,

This is my first post. The vast knowledge in this forum is very impressive, and I hope to become more a part of it. I hope you can help with a question I have.

I was just reviewing my cancer drugs, and ran into a dead end when trying to classify Doxorubicin and Daunorubicin. I've known that Doxorubicin inhibits Topoisomerase II. In regards to Daunorubicin, my pharm professor mentioned some time ago that Daunorubicin inhibits the action of Topoisomerase IV. First Aid, however, classifies both Doxo- and Dauno-rubicin as having the same function.

Further investigation showed that Topoisomerase II is subcategorized into Topoisomerase IIA complex and Topoisomerase IIB complex. The Topoisomerase IIA complex is further subcategorized as a three-enzyme complex: (1) DNA Gyrase, (2) eukaryotic Topoisomerase II, and (3) bacterial Topoisomerase IV.

So my question is how am I supposed to classify these drugs, as far USMLE testing goes? Assuming my pharm professor was correct, I'm having difficulty finding other evidence that supports her claim of Daunorubicin inhibiting Topo IV. Any help would be much appreciated. Have a great day!

Regards,
Niloy

Hmmm,
Its not common to ask you about the details as this is not the strategy of step 1 especially with hematology oncology division details is not an issue and am 100% positive of that.
Now both r the same from usmle steand point and the answer they r intercalate within DNA grooves and they inhibit topoisomerase,gyrase and they have cardiotoxiity because of free radical injury.
That what most likely the test want you to know
The test would not test you how much you know but they need to know how you handle the information that u have .
best of luck
Riyadh