Treatment Schedule

Elliott’s short-term plan depended upon an assessment of his liver function (he has a history of liver disease and the lymphoma has spread to his liver, see the About page) and a genetic test for an MDR1 gene mutation.  His liver function turned out to be ok (good enough), and he is negative for the mutation so he officially started the Wisconsin-Madison Canine Lymphoma Protocol on July 1st 2010.  This is the COP protocol + doxorubicin, aka the CHOP protocol.  If things continue to go ok, the protocol is:

week 1: 6-24-10: Cytoxan IV. Prednisolone 15mg BID through evening of 6-30-10

week 2: 7-1-10: Vincristine IV administered after MDR1 results arrived. Pred 10mg BID today through evening of 7-7-1.

week 3: 7-8-10: doxorubicin-1. Pred 5mg BID through evening of 7-14-10. Started omeprazole for possible GI bleeding.

week 4: 7-15-10: recheck blood for “nadir CBC”. Pred 5mg SID through evening of 7-21-10.

week 5: 7-22-10: vincristine IV. Pred 5mg every other day starting tomorrow, for three doses.

week 6: 7-29-10: Cytoxan IV or PO? undecided. Off pred!

week 7: 8-5-10: vincristine

week 8: 8-12-10: doxorubicin-2

week 9: 8-19-10: break

week 10: 8-26-10: vincristine

week 11: 9-2-10: break

week 12: 9-9-10: Cytoxan

week 13: 9-16-10: break

week 14: 9-23-10: vincristine

week 15: 9-30-10: break

week 16: 10-7-10: doxorubicin

week 17: 10-14-10: break

week 18: 10-21-10: vincristine

week 19: 10-28-10: break

week 20: 11-4-10: Cytoxan

week 21: 11-11-10: break

week 22: 11-18-10: vincristine

week 23: 11-25-10: break

week 24: 12-2-10: doxorubicin-4.  This is usually the maximum (lifetime) amount of administrations due to inevitable cardiotoxicity.

People familiar with the protocol will notice that one week is missing; this is the first week in which Elspar and vincristine are usually given.  We did not give those because my dog’s liver function and MDR1 status had not been established, so we started with “week 2”, Cytoxan.  I don’t know if his oncologist will alter or add something in later on.

Drugs and side effects: Cytoxan, vincristine, and doxorubicin can all cause inappetance, diarrhea, vomiting, and blood abnormalities such as anemia (low RBC) and leukopenia (low WBC). Particular side effects with each include:

Cytoxan (cyclophosphamide): hemorrhagic (bloody) cystitis (bladder irritation) is the potential big awful side effect.  It is uncommon, but affected dogs may dribble blood for months, and there is no cure. To counter this, IV Cytoxan can be given with a powerful diuretic (Lasix aka furosemide) and the dog can be walked every 15 minutes for 2-3 hours to evacuate most of the residual Cytoxan from the bladder.  Cytoxan also comes in an oral form and it is considerably cheaper; however, the dose must be spread over 4 days and can’t be accompanied by Lasix, so the risk for cystitis might be higher.

Vincristine: This drug can cause pretty bad diarrhea.  In Elliott (after his one treatment) I noticed it caused him to retain food in his stomach.  This side effect is partial GI paralysis; the GI tract slows down to a crawl and food moves more slowly than normal.  This wasn’t a big deal in him and did not require treatment.

Doxorubicin: This is the most powerful chemo agent and has the best effects against cancer, and the most side effects.  It can cause profound leukopenia, and can cause bad diarrhea, and also has the potential to irreversibly damage the heart muscle.  It is usually only given a maximum of four times within a dog’s lifetime.  It may be given an additional 1-2 times in cases of refractory cancer (when you have nothing to lose :().

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Responses

  1. I have a 5 year old male collie that is MDR1 and has lymphoma. I was nervous about giving him the cyclophosphamide the vet sent home although they are aware of the MDR1. This article made me feel better about it, although the potential side effects are awful. Thanks for putting this info out there. it is bad enough having to have my sweet boy go through this without the added complication of the mutation.


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