Discover The Different Types Of Chemotherapy
Chemotherapy is one of the most popular treatments for cancer. This involves a wide range of medications, which is why there are different types of chemotherapy.
The goal of chemotherapy is to kill the cancer cells to cure the disease. But all types of chemotherapy affect both targeted and healthy cells. Thus, serious side effects occur.
In the following, we will present the most popular forms of this treatment and their characteristics.
The main types of chemotherapy
Alkylating agents
Alkylating agents reach the highest level of activity in the resting phase, but are not specific to a particular phase of the cell cycle. Physicians may recommend the following categories of alkylating agents in chemotherapeutic treatments:
- Hyperite (mustard gas) derivatives: Such as, for example, cyclophosphamide.
- Ethyleneimines: Haxamethylmelamine is an example.
- Hydrazines and triazines: Include altretamine and procarbazine, among others
- Nitrosures: They are unique because, unlike most chemotherapeutic substances, they can cross the blood-brain barrier, ie the membrane that protects the brain. Therefore, nitrosides can be used to treat brain tumors.
- Metal salts
Alkaloids of plant origin
These chemotherapeutic substances are obtained from certain plants. For example, vinca alkaloids come from the Madagascar honeysuckle ( Cartharanthus rosea ). This group also includes taxanes, obtained from the Pacific yew tree ( Taxus previfolia ).
Unlike alkylating agents, all alkaloids of plant origin attack cells only in specific phases of their cycle. In addition to vinca and taxane alkaloids, this group also includes podophyllotoxins and camptothecin analogues.
Antitumor antibiotics
And chemotherapy with antitumor antibiotics is based on natural substances. But this type of medicine is not obtained from plants, but from fungi belonging to the genus Streptomyces .
Like plant alkaloids, antitumor antibiotics act on tumor cells at different stages of the cell cycle. Examples of such drugs are:
- Anthracyclines, such as doxorubicin and epirubicin, which have long-term cardiotoxic effects
- Chromomycins (for example, dactinomycin)
- Mitomycin
- Bleomycin
Antimetabolites
Antimetabolites are very similar to the natural molecules in cells. Therefore, when cells absorb them, cell division is disrupted.
Antimetabolites are classified according to the substances they act on:
- Folic acid antagonists (methotrexate)
- Pyramidine antagonists (5-fluorouracil and capecitabine)
- Purine antagonists (6-marcaptopurine)
- Adenosine deaminase inhibitors (cladribine, fludarabine, nelarabine and pentostatin)
Topoisomerase inhibitors
The effectiveness of these drugs is due to their ability to inhibit the activity of the enzymes topoisomerase I and topoisomerase II. Both of these enzymes manipulate the structure of DNA, making it possible for cancer cells to multiply. Two examples of topoisomerase inhibitors are irinotecan and etoposide.
Various antineoplastics
As the name suggests, the latter group includes chemotherapeutic drugs that do not belong to the other categories because they are unique. These include:
- Mitotane
- Asparaginase and pegasparagase
- Estramustina
- Retinoids
conclusions
In addition to chemotherapy, there are many other useful therapies for cancer, such as immunotherapy or hormone therapy. All of these therapeutic agents have made great strides in the fight against cancer.
But there are still many challenges that need to be overcome, and therapeutic research needs to continue. The ultimate goal is to discover chemotherapies with specific action, which attack only tumor cells.
