This is how cytostatics work
Cytostatics are substances that inhibit cell growth and/or cell division. They are primarily used as part of chemotherapy for cancer . Because cytostatics attack cells that divide quickly. This is the case with cancer cells, which multiply through uncontrolled cell division, but also with some healthy body cells. These cells include the mucous membrane cells in the mouth and in the gastrointestinal tract , the cells in the bone marrow and the hair cells. Cells that do not divide during treatment, on the other hand, are usually not affected by the drugs.
Cytostatics inhibit cell division
Cytostatics ensure that the division and uncontrolled growth of tumor cells are inhibited and the cells die. For this purpose, some substances build errors in the DNA of the tumor cells or inhibit the copying process of the genetic material, which is essential for the division of the cell. Other cytostatics influence the metabolism of the cell.
The damaged or dead cells are recognized and broken down by an endogenous control mechanism. If the therapy works, the tumor becomes smaller or at least stops growing. However, whether chemotherapy is successful or not cannot be seen overnight: it usually takes a few days or even a few weeks before it becomes apparent whether the treatment is working.
The success of the treatment is checked at regular intervals. Treatment is considered successful when the tumor stops growing, has shrunk or has disappeared completely. An improvement in the subjective well-being of the patient is also rated as a success.
Various active ingredients
Many different cytostatics are available for chemotherapy. Which drug is used in an individual case depends, among other things, on the type of cancer. Below you will find a list of the most important cytostatics.
alkylating agents
Alkylating agents prevent the duplication of the genome in the tumor cells, which is essential for cell division. This prevents the cells from multiplying and the tumor from growing. The group of alkylating agents includes active substances such as busulfan, cyclophosphamide and ifosfamide.
The so-called platinum analogues are also counted among the alkylating agents in the broader sense . They fight the tumor cells by connecting with the genetic information in the tumor cells and thereby destroying them. They also inhibit those enzymes that could repair the damage caused to the DNA.
Since platinum analogs can cause severe nausea , concomitant medications are usually administered. Active ingredients from this group are cisplatin, carboplatin and oxaliplatin.
Antibiotics
Just like cytostatics, antibiotics inhibit the growth and proliferation of cells. However, most antibiotics target foreign cells. Only a few inhibit the proliferation of endogenous cells and can therefore be counted among the cytostatics.
These antitumor antibiotics cause breaks in the DNA of tumor cells and cause changes in the cell membrane. Since they are not only effective during the cell division phase, they usually have more side effects than other cytostatics. The group of antitumor antibiotics includes active ingredients such as doxorubicin and epirubicin.
Antimetabolite
Antimetabolites destroy the cells’ genome by infiltrating the cells’ DNA as wrong building blocks. They work during cell division and have relatively few side effects compared to other cytostatics .
The group of antimetabolites includes active substances such as:
- methotrexate
- Fluorouracil
- Cladribin
- Fludarabin
- of Tioguan
Hormone
Strictly speaking, hormones do not belong to the cytostatics. However, they can be helpful in the context of chemotherapy for those tumors whose growth is stimulated by hormones. For example, female sex hormones promote the growth of breast cancer , male sex hormones that of prostate cancer . The use of the respective opponents can curb the growth of the tumors. Depending on the type of cancer, antiestrogens or antiandrogens are administered.
Mitosis inhibitor
Mitosis inhibitors prevent the cell nuclei of the tumor cells from dividing. If this process is blocked, the cells cannot multiply. Mitosis inhibitors include many plant substances, including vinca alkaloids and taxanes.
- Vinca alkaloids: They are obtained from the periwinkle (vinca) plant. Examples of active ingredients from this group are vinblastine and vincristine.
- Taxanes: They are obtained from yew bark. Examples of drugs from this group are docetaxel and paclitaxol.
Topoisomerasehemmer
Topoisomerase inhibitors block the enzyme topoisomerase, which allows cells to multiply. If the topoisomerases of the cancer cells are inhibited, the tumor can no longer grow. Examples of topoisomerase inhibitors are etoposide, irinotecan and topotecan.
