(Den 1140) Pharmacology: week 9 (Anti-neoplastic drugs/chapter 20)

Use of antineoplastic agents:

• Antineoplastic agents are used clinically

to interfere with neoplastic cells

• Suppress growth and attempt to destroy

and prevent the spread of malignant cells

• May be used alone or in combination or

with radiation or surgery

• Current philosophy involves treating the

initial stages of the disease very aggressively

mechanism of action of antineoplastic drugs

-interfere with the metabolism or reproductive cycle of the tumor cells.

- cycle consists of four stages.

- G0 stage: resting stage, not in a process of cell division, Cells enter the cycle, difficult to reach and destroy

Most of the antineoplastic agents are labeled as being either cell cycle- specific or non specific

Cell cycle-specific:

Antimetabolites

Bleomycin

Vinca alkaloids

Podophyllin

Cell cycle-nonspecific :

Alkylating agents

Antibiotics

Cisplatin

Nitrosoureas

Immunotherapy drugs (protein kinase inhibitors), called immune checkpoint inhibitors, block the......

checkpoint proteins from binding to the partner proteins and the "off" signal is never sent, allowing the T-cells to kill the cancer cells

Monoclonal antibodies are

immune system antibodies that are created in laboratories. These drugs recognize cancer cells and destroy them

Classification: Alkylating Agent:

alkyl radicals that react with DNA in all cycles of the cell, preventing reproduction.

Classification: Antimetabolites:

atack the cells in the S phase of reproduction by interfering with purine or pyrimidine synthesis, more effective against rapidly proliferating neoplasms.

Classification: Plant alkaloids:

are mitotic inhibitors that act by arresting cells in metaphase, low bone marrow toxicity, often used in combination with other agents that are more toxic

Classification Antibiotics:

cycle-nonspecific and are effective for solid tumors

Classification: Prednisone:

interrupt the cell cycle at the G stage.

Classification: Steroids:

suppress lymphocytes in leukemias and lymphomas and in combination therapies

Classification: Estrogens:

palliation in inoperable breast cancer

Classification: Tamoxifen:

antiestrogenic substance, is used to manage and prevent breast cancer.

Classification: Cisplatin:

heavy metal complex of platinum, is cell cycle-nonspecific

Classification: Hydroxyurea:

inhibits ribonucleoside diphosphate reductase, which would otherwise interfere with the conversion of ribonucleoside diphosphates to deoxyribonucleoside diphosphates.

Classification: Procarbazine:

produces chromosomal breakage.

Adverse drug effects:

normal cells become destroyed. Early side effects with GI, none marrow and hair follicles.

-Bone marrow suppression: results in low WBC or anemia.

-Osteonecrosis

-GI: nausea, stomatitism oral ulcerations. Nausea and vomiting can be treated.

-Dermatologic effects: erythema, steven-Johnson syndrome.

- Hepatotoxicity: liver problems.

-Neurologic Effects: adh hormone, convulsions.

-Nephrotoxicity: Allopurinol prevents hyperuricemia.

-Immunosuppression.

-Germ cells.

Osteonecrosis:

-Bisphosphonates help bone but cause osteonecrosis.

- Higher in cancer patients on iv bisphosphonates.

-Called MRONJ.

Symptoms: Exposed bone, pain, gum swelling, and tooth loosening.

-4 stages (0-3)

-Treatment: Difficult, antibiotics and pain med, surgery.

-Prevention: dental care before bisphosphonate therapy; minimal bone manipulation during surgery; chlorhexidine rinses.

-Caution: stopping bisphonantes temporarily isn't advised due to long-term effects.

Oral effects:

Discomfort, sensitivity, mucosal pain, ulceration, gingival bleeding, dryness, and impaired taste

Tips for Home Oral Hygiene:

-Keep mouth moist with water, ice chips, or saliva substitutes.

-Brush teeth gently twice daily with soft-bristle brush and fluoride toothpaste.

-Use alcohol-free mouth rinse and floss daily.

-Avoid sharp, crunchy, sugary, caffeinated, and alcoholic foods/drinks.

Oral Mucositis:

Treatment for Oral Mucositis:

mouth sores, inflammation, and pain.

-Over-the-counter pain relievers, saline rinses, topical anesthetics, and ice chips can provide relief.

Hyposalivation (Xerostomia):

Sip water, use artificial saliva, rinse with baking soda and salt mixture, chew sugarless gum.

Combination Therapy

Different drugs with varied actions used together to inhibit cancer cell growth effectively.

-Synergistic Effect: Combined drugs can enhance cytotoxicity while reducing side effects.

-Examples: Azathioprine, methotrexate, and cyclosporine used in lower doses for inflammation, autoimmune diseases, and transplantation.

-Lower Doses: Autoimmune disease treatments often use lower doses compared to cancer, reducing certain risks.

Dental hygiene considerations

- meet with the patient prior to beginning chemotherapy in order to outline an optimal oral hygiene plan

- meet with the patient during and after chemotherapy in order to adjust

- receive maximum oral hygiene and health care prior to chemotherapy

- Dental procedures should be avoided during chemotherapy because the patient is at high risk for infection as a result of low white blood cell counts and platelet.