Since cytostatic drugs are (cell-)toxic drugs that effectively damage the tumour, but at the same time affect healthy cells during chemotherapy, they must be given time to recover. That is why chemotherapy is not given every day like many other drugs, but in so-called cycles. This means that cytostatic drugs are given at certain intervals, but in the intervals in between, the body is given time to regenerate.
Of course, the tumour also has time to recover, but it is not able to do this as well as the normal cells. Thus, when chemotherapy is administered, more and more tumour cells are tried to die than can grow back during the recovery phase. How exactly the time intervals (the treatment scheme) are chosen varies from patient to patient.
In most cases, however, the patient goes through at least 2 cycles before decisive successes (a reduction in the size of the tumour (diagnosed by imaging procedures such as CT, MRT) or improvement of the symptoms) can be demonstrated. The dosage of the cytostatic drugs is usually based on the body surface, in addition it must be adjusted to the liver and kidney values. Tyrosine kinase inhibitors also belong to the group of chemotherapeutic drugs.
In contrast to the classical chemotherapeutic drugs, however, the tyrosine kinase inhibitors act specifically and thus cause fewer side effects. The chemotherapy is usually carried out in hospital. This is necessary because the patient must be under constant medical observation.
The doctor must be sure that no unexpected side effects of the chemotherapy occur. If the patient is in good general condition, he or she can have the chemotherapy administered on an outpatient basis in a so-called day clinic for a few hours and then go home again. However, it is often important for patients to stay in hospital for a longer period (they are admitted as inpatients).
On the one hand, this allows the patients to be given some additional infusions before the chemotherapy is administered, which should better prepare the kidneys to be able to excrete the toxic cytostatic drugs more quickly (this is called “pre-watering”). On the other hand, one has the possibility to regularly check the kidney function and other important parameters by examining the blood of the patients. This blood check is also carried out before chemotherapy.
If not all important values are in order (such as the white blood cells (leukocytes)), the chemotherapy must be postponed. Cytostatic drugs can be administered in 2 different ways: The so-called bolus is also given via the vein, in which an increased amount of the substance is quickly (1-10 min) introduced into the body. Here a high concentration of the substance is reached in the body in a short time.
Finally, it should also be mentioned that nausea medication is often given as a preventive measure (prophylactic) in parallel with or before chemotherapy. – In most cases the administration is intravenous: the doctor has to puncture a vein in the arm and insert an access (a catheter). An alternative is the so-called port system, in which a permanent catheter is usually inserted into the vein under the collarbone (subclavian vein), which is connected to a small box that is placed under the skin.
This small box can be easily reached from the outside. In this way the constant painful puncture of a vein in the arm can be avoided. Since the infusion can only enter the vein slowly, the procedure takes several hours.
If administered too quickly, the body would be overtaxed and thus lead to avoidable damage. You hardly feel the chemo infusion running into you. However, if pain occurs acutely in the arm or anywhere else, the doctor must be informed immediately, as this should be investigated immediately.
- Oral application: means taking tablets. However, this procedure can only be used for a few substances. Although taken by mouth, the active ingredients of the medication also end up in the blood, and therefore have a systemic effect. Of course, the advantage of this method is that patients avoid the long and painful process of intravenous administration.
