How is chemotherapy given?

Chemotherapy treatments may be given orally or by injection, either into a vein (intravenous injection), into the muscle (intramuscular or IM injection), or under the skin (subcutaneous or SQ injection) (fig.1)

Figure 1: Materials used to safely inject small amounts of chemotherapy intravenously.

. A drug may be administered orally for several days in a row or every other day for several days, followed by a "rest period" with no drugs to be given. Other drugs may be given orally or by injection in one dose, followed by a few weeks without treatment to allow the normal tissue time to recover from the damage inflicted by the drug. The protocol of drugs to be given in regular intervals is called a cycle; your oncologist will specify how the drugs are to be administered and at what days when he or she explains the protocol to you. The number of cycles an animal receives may be somewhat flexible, depending on the tumor's response to the drugs. It is not uncommon to have to delay a cycle or two during the protocol administration because the patient's white blood cell count is too low to continue therapy. In most instances, delaying administration of the next drug or drugs for a few extra days does not adversely affect the animal's prognosis, and it is certainly helpful in preventing serious side effects.