Even at low doses Cytoxan can cause cystitis.  Some dogs get an actual infection and some just get inflammation with straining and bloody urine.  Giving a diuretic (Lasix) may help reduce these side effects.  It seems that females are more likely to develop this problem.  In most cases the cystitis will resolve once the Cytoxan is discontinued but a small percentage of dogs will need sedation and flushing of the bladder along with DMSO or other anti-inflammatories.  This can be a very painful problem so in general most oncologists will not use Cytoxan again if cystitis occurs.

The two other chemo drugs most commonly substituted are CCNU (Lomustine) or chlorambucil (Leukeran).  CCNU can cause low platelets or elevated liver enzymes in some dogs.  Leukeran is pretty benign but might cause bone marrow suppression.  I had to stop Cytoxan in Tazzie because of a very bad bladder infection (Pseudomonas cystitis which took 6 weeks of antibiotics to resolve).  I tried CCNU with my other dog Kona and her liver enzyme became too elevated but returned to normal after I stopped the drug.

Maximutt's Cytoxan dose does seem high.  Tazzie weighs 185# and her dose was 25 mg once daily.  Even a slightly elevated dose can increase the risk of problems so that is why most dogs need it compounded. 

Metronomics is a new field so you will see many oncologists trying new drugs and combos to increase the success rate.  Above all we should try to do no harm and since Tazzie is still in "prevention mode" I decided to only do the Metacam without a chemo drug. I might try a different drug later if she gets mets.

Pam and Tazzie

I have no idea what Actos would be for.  I have seen some vets adding Doxycylcine (antibiotic) in an effort to decrease new blood vessel formation but I have not come across that drug before.  I would ask your oncologist if they have heard of it or used it.

Pam