Chemotherapy Study Notes

Introduction to Chemotherapy

• Module 5 of Pharmacology focuses on chemotherapeutic agents.

  • Aim is to study pharmacokinetics and pharmacodynamics of drugs.

  • Understand how administration, distribution, metabolism, etc., influence drugs' effects.

  • Focus on safety principles related to chemotherapeutic agents in physical therapy practice.

  • Overview of drug categories used for cancer treatment.

  • Discuss physiological mechanisms of drug classes affecting cancer treatment and other organ systems.

  • Explore application in physical therapy interventions.

Understanding Cancer

• Definition of Cancer:

  • Rapid, uncontrolled cell proliferation in the body.

  • Conversion of normal cells into more primitive, undifferentiated states.

  • Malignant neoplastic diseases invade local tissues and can metastasize.

• Importance of Understanding Cancer and Chemotherapy:

  • Cancer is the second leading cause of deaths in the U.S., following cardiovascular disease.

  • High likelihood of treating patients undergoing cancer treatment.

  • Physical therapists can advocate for patients navigating cancer treatment.

• Causes of Cancer:

  • Causes are poorly understood; believed to involve environmental, viral, genetic factors.

  • Positive lifestyle habits may prevent some cancers:

  • Importance of exercise.

  • Avoidance of tobacco.

  • High-fiber diet.

  • Overall healthy lifestyles supported by physical therapy.

Cancer Treatment Modalities

• Three primary modalities to treat cancer:

  • Surgery

  • Radiation

  • Chemotherapy (focus of this lecture)

Key Focus Areas for Chemotherapy Drugs

• Mechanism of Action:

  • Understand if drugs are cell cycle specific or non-specific.

  • Efficacy and safety of each drug.

• Example Disease Effects:

  • Understanding associated side effects with specific medications.

  • Knowing which side effects to report based on expectations.

Anti-Cancer Drug Mechanisms

• Aim of Anti-Cancer Drugs:

  • Limit cell proliferation and kill/attenuate growth of cancerous cells.

• Challenge of Selective Toxicity:

  • Targeting own cells leads to difficulty in achieving selective toxicity.

  • Generally low therapeutic index for these medications.

• Mechanisms of Action:

  • Inhibition of DNA or RNA synthesis.

  • Cell-specific inhibition during phases of cell division, especially mitosis.

Classification of Anti-Cancer Drugs

• Types of Anti-Cancer Drugs:

  • Cell Cycle Specific Drugs:

  • Affect cells at specific points in the cell cycle (e.g., synthesis phase, mitosis).

  • Cell Cycle Non-Specific Drugs:

  • Impact cells regardless of their position in the cycle.

• Growth Fraction:

  • Defined as the percentage of proliferating cells within the cancerell population.

  • Growth fraction decreases as tumors grow larger.

  • Cell cycle specific drugs become less effective as growth fraction decreases.

Implications for Physical Therapy

• Understanding Drug Classification Impacts Treatment:

  • Knowledge of drug types may indicate cancer stage or treatment strategy.

  • Awareness of chemotherapy effects aids in patient management.

• Role of Chemotherapy in Cancer Management:

  • Chemotherapy aims to reduce tumor size for the body’s immune system to eliminate remaining cells.

  • Patients can be considered in remission when the body eliminates the remaining cancer cells.

Adverse Effects of Chemotherapy

• Chemotherapeutics impair replication of normal tissues.

• Effectiveness depends on drug specificity (cell cycle specific vs. non-specific).

• Commonly Affected Tissues with Side Effects:

  • Cell cycle-specific agents tend to target frequently replicating tissues such as:

  • Hair

  • Bone marrow & associated blood components

  • Immune system cells

  • Skin

  • Gastrointestinal (GI) tract

• Distinguishing Side Effects:

  • Understanding expected effects helps manage patient symptoms.

  • Identification of severe side effects that require communication with healthcare providers.

  • Differentiation between disease process symptoms and medication-related adverse effects.

Further Exploration of Drug Classes

• The lecture will continue with a discussion on specific drug classes used in chemotherapy.