Daunorubicin: this is administered during the first Induction phase. It binds to the DNA and intercalates with it i.e. it inserts a molecule of itself in between the DNA molecules. This distorts the DNA, messing with the way it functions and preventing it from replicating.
In the picture above normal DNA is shown on the left and DNA intercalated at three locations (in red) is shown on the right.
Doxorubicin: this is given in the two Delayed Intensification phases (4 and 6). It binds to the DNA and inhibits the enzyme which unwinds the DNA double helix to be read for copying. It stops the enzyme from resealing the double helix thereby stopping replication.
Both drugs are administered by IV drip.
One of the side-effects of both these drugs is feeling sick (nausea) and vomiting. For this the gluco-corticoid (a steroid), Dexamethasone, is given. As well as combatting the side-effect of nausea, Dexamethasone is also used as a first-line treatment drug in later maintenance phases. For this reason, I'll leave its discussion until a later post (as I'm still trying to get my head around how it works!).
Another side-effect of the anthracyclines is hair-loss. In young adults, this can be a major psychological issue (Lucia discusses it in her blog – link on right). However, although it has happened to Kezia, she has not yet developed the self-consciousness for it to be a problem. I think Nanda and I have been more effected – Kezia's hair was so beautiful! However, it will grow back!