Cytoxan... how does it work?

When I started this blog, I wasn't sure if I was going to share it, I figured it would just be an outlet for how I was dealing with my best friends illness.  The more I thought about it, the more I realized that there are probably tons of owners out there that have no idea what chemotherapy is all about.  I mean, we all know that it is a cancer treatment, but what does it do to our pet's bodies?  How does it work?  Even though I have been in the veterinary field for almost 10 years now, I have only had one real encounter with chemotherapy prior to my own cat's diagnosis.  Needless to say, the treatment didn't work well and it was a long difficult battle for the cat that was fighting small cell lymphoma in his GI system.  When I was given my options for Stinky, I was at a loss.  I couldn't afford radiation, and doing nothing wasn't an option.  My decision to do chemo was a dedication to Stinky to do the best I could at helping him get through it, with his health being my priority.  This meant I was not going to just treat his cancer, but actually understand his treatments.  So, that's what lead me to sharing this journey.  I have the ability to just read veterinary journals, but I'd rather put what I find in terms for other owners to understand. 

Ok... so, what is Cytoxan??
Cytoxan, also known as Cyclophosphamide, is a chemotherapy drug belonging to a group of medications called Alkylating agents.  Apparently, this group of drugs have been around for a long time, being one of the first classes of drugs to treat cancer.  These alkylating agents work by reacting with the proteins that link up to make the DNA double helix.  The agents add an alkyl group to the proteins that bond together, preventing the normal proteins to link up like they should, causing them to break.  This leads to cell death.  Again, think back to high school biology...

G-C and A-T  (GCAT... that's how I remembered it)

Alkylation is a little more complex, but what we really need to know is that it causes the DNA helix to not coil or uncoil properly when replicating.  It is a mutation that leads to cancer cell death by taking away the ability for cancer cells to multiply.  Alkylating chemotherapy agents affect every life cycle of cancer cells, so they are quite common and effective in the treatments of many different cancers.

According to many sources that I've read, the biggest side effect in cats is inappetence, vomiting, or diarrhea (which we have been lucky not to experience).  Other side effects include bone marrow suppression between 5 and 14 post dose, and sterile hemorrhagic cystitis.  Some dogs may have alopecia (fur loss) and some cats may lose their whiskers. 

Fingers crossed!  Things are going well for Stinkeroo, lets hope it continues!