Chemotherapy drugs

Overview

Chemotherapy drugs are medications administered during chemotherapy to target and destroy cancer cells. These drugs come in various forms, each with distinct mechanisms of action. All chemotherapy drugs are designed to target rapidly dividing cells, such as cancer cells. As a widely used and effective method for treating cancer, chemotherapy works by eliminating these fast-growing cells and hindering their ability to replicate.

Chemotherapy can lead to side effects because these medications also affect other rapidly dividing cells, such as those in the skin and digestive tract.

All cells, including both cancerous and healthy ones, go through a process known as the cell cycle, where they replicate their DNA and divide to create new cells. Healthy cells generally reproduce as needed and undergo programmed cell death (apoptosis) when they are no longer necessary. The cancer cells evade this natural cycle, continuously multiplying uncontrollably and forming tumors that can harm surrounding healthy tissues.

Chemotherapy drugs disrupt the cell cycle to eliminate cancer cells and prevent their proliferation. Different chemotherapy medications employ various strategies to interrupt the cell cycle and combat cancer effectively.

Types

Chemotherapy drugs are categorized according to their composition and mechanisms for destroying cancer cells. Some drugs are most effective during particular stages of the cell cycle, while others can target cancer cells throughout all phases of the cycle.

Your oncologist will determine the ideal timing and dosage for administering chemotherapy drugs as part of your treatment plan.

You might receive either a single type of chemotherapy drug or a combination of drugs, known as combination chemotherapy. Using multiple drugs can enhance treatment efficacy because different drugs attack cancer cells in various ways. Additionally, combining drugs can help minimize the risk of your body developing resistance to any one drug, which can render it ineffective over time.

• Alkylating agents (including nitrosoureas): Alkylating agents work by damaging the DNA of cells, which inhibits the division of cancer cells. Nitrosoureas are a specific class of alkylating agents with the unique ability to cross into the brain and target cancer cells within the brain. This makes nitrosoureas particularly useful for treating certain brain tumors. Some examples of alkylating agents include:
  • Altretamine.
  • Bendamustine.
  • Busulfan.
  • Carboplatin.
  • Chlorambucil.
  • Cisplatin.
  • Cyclophosphamide.
  • Dacarbazine.
  • Ifosfamide.
  • Mechlorethamine.
  • Melphalan.
  • Oxaliplatin.
  • Procarbazine.
  • Temozolomide.
  • Thiotepa.
  • Trabectedin.

  Some examples of nitrosoureas include:

  • Carmustine.
  • Lomustine.
  • Streptozocin.
• Antimetabolites: Antimetabolites interfere with the production of genetic material necessary for cancer cells to generate new cells. Some examples of antimetabolites include:
  • 5-fluorouracil.
  • 6-mercaptopurine.
  • Azacitidine.
  • Capecitabine.
  • Cladribine.
  • Clofarabine.
  • Cytarabine.
  • Decitabine.
  • Floxuridine.
  • Fludarabine.
  • Gemcitabine.
  • Hydroxyurea.
  • Methotrexate.
  • Nelarabine.
  • Pemetrexed.
  • Pentostatin.
  • Pralatrexate.
  • Thioguanine.
  • Trifluridine/tipiracil combination.
• Topoisomerase inhibitors: Topoisomerase inhibitors work by blocking an enzyme called topoisomerase, which is crucial for DNA replication. By inhibiting this enzyme, these drugs prevent cancer cells from multiplying and can also cause damage to the cell’s DNA. Some examples of topoisomerase inhibitors include:
  • Etoposide.
  • Irinotecan.
  • Irinotecan liposomal.
  • Mitoxantrone (also classified as an antitumor antibiotic).
  • Teniposide.
  • Topotecan.
• Mitotic inhibitors: Mitotic inhibitors, also known as plant alkaloids, are derived from natural plant substances that plants use for defense against predators. These drugs disrupt the process of mitosis, which is essential for cancer cell division and reproduction. By interfering with this process, mitotic inhibitors prevent cancer cells from multiplying and forming new cells. Some examples of mitotic inhibitors include:
  • Cabazitaxel.
  • Docetaxel.
  • Nab-paclitaxel.
  • Paclitaxel.
  • Vinblastine.
  • Vincristine.
  • Vincristine liposomal.
  • Vinorelbine.
• Antitumor antibiotics (including anthracyclines): Antitumor antibiotics inhibit the DNA replication process within cancer cells, and they can also cause damage to the cell’s DNA. Anthracyclines are a specific category of antitumor antibiotics. Some examples of anthracyclines include:
  • Daunorubicin.
  • Doxorubicin.
  • Doxorubicin liposomal.
  • Epirubicin.
  • Idarubicin.
  • Mitoxantrone.
  • Valrubicin.

  ome antitumor antibiotics may include:

  • Bleomycin.
  • Dactinomycin.
  • Mitomycin-C.
• Other chemotherapy drugs: Chemotherapy drugs don’t all fall into the primary categories. Additional commonly used options include:
  • All-trans-retinoic acid.
  • Arsenic trioxide.
  • Asparaginase.
  • Eribulin.
  • Ixabepilone.
  • Mitotane.
  • Omacetaxine.
  • Pegaspargase.
  • Procarbazine.
  • Romidepsin.
  • Vorinostat.
• Corticosteroids: Corticosteroids are generally not classified as chemotherapy treatments. They are prescribed for various conditions, but many patients on chemotherapy also use corticosteroids to alleviate side effects. Additionally, these drugs can kill cancer cells and inhibit their division. Some corticosteroids commonly used during chemotherapy are:
  • Dexamethasone.
  • Hydrocortisone.
  • Methylprednisolone.
  • Prednisolone.
  • Prednisone.

Reasons for undergoing the procedure

Chemotherapy drugs are mainly employed to treat cancer. Medical oncologists, who are specialists in cancer care, frequently prescribe these drugs alongside other treatments such as surgery, radiation therapy, immunotherapy, or targeted therapy to combat cancer.

Chemotherapy drugs can be used to address a variety of conditions beyond cancer, including:

• Blood disorders: Blood disorders often involve the production of abnormal blood cells by the bone marrow. For some of these conditions, a stem cell transplant might be necessary to replace defective cells with healthy ones. Chemotherapy is frequently administered before a transplant to eliminate the abnormal cells and create space for new, healthy cells.
• Autoimmune diseases: In autoimmune diseases, the immune system mistakenly attacks the body’s own healthy tissues. Chemotherapy can help by inhibiting the proliferation of these immune cells, thereby reducing the damage they cause.

Risks

Chemotherapy drugs are designed to target cells that divide and grow rapidly. While this helps in attacking cancer cells, it also affects other rapidly dividing non-cancerous cells in your body. These include cells in your skin, hair follicles, mouth, digestive tract, and blood-forming cells in the bone marrow. As a result, chemotherapy can lead to a range of side effects, such as:

• Decreased appetite
• Diarrhea
• Constipation
• Nausea and vomiting
• Fatigue
• Hair loss
• Mouth sores

Additionally, chemotherapy can reduce your blood cell counts, increasing the risk of anemia and neutropenia. Neutropenia impairs your immune system’s ability to combat infections.

The likelihood and severity of these side effects can vary depending on the specific chemotherapy drugs you are receiving. It’s important to discuss with your healthcare provider which side effects are most likely with your treatment regimen.

Outcome

Chemotherapy drugs have significantly enhanced the prognosis for many cancer patients, transforming previously fatal cancers into treatable conditions. As a result, numerous individuals are now enjoying longer, more fulfilling lives. Depending on your specific cancer diagnosis, chemotherapy can:

• Eradicate cancer to prevent its return.
• Stop cancer from spreading to improve your longevity and well-being.
• Alleviate symptoms to help you lead a full life despite a chronic illness.

Your overall prognosis depends on factors such as your general health, cancer type, stage, and the treatments you are undergoing. Treatment goals also play a role. For instance, chemotherapy might be used as an initial treatment to eliminate cancer, to shrink tumors before surgery, to target residual cancer cells post-surgery, or to alleviate symptoms.

Discuss your outlook with your healthcare provider, tailored to your specific treatment goals. If you encounter troublesome side effects during chemotherapy, reach out to your oncologist. They can offer strategies to manage these effects and, if necessary, prescribe medications to alleviate them. In some cases, your oncologist might adjust your dosage, treatment schedule, or explore alternative medications to better address your cancer.