Drug Action Interactions & Toxicology

Factors Affecting Drug Effects

Drug Interactions

• Discussion begins on factors affecting drug effects, particularly focusing on interactions that can increase or decrease therapeutic effects and adverse effects.

• Emphasis on drug-to-drug interactions, highlighting the potential for unexpected effects when multiple drugs are taken together, especially concerning protein binding sites.

• Introduction of receptor interactions as a form of drug interaction that can lead to potentiating effects.

Herbal and Food Interactions

• Mention of herbal product interactions with conventional drugs, stressing the importance of being cautious with herbal medicines.

• Specific examples of food-drug interactions provided, such as green leafy vegetables with dairy products affecting insulin and antibiotics like tetracycline leading to decreased effectiveness due to chemical binding.

Grapefruit and Other Foods

• Grapefruit noted for decreasing metabolism of certain drugs, potentially increasing their effect; caution advised regarding aged cheese and wine in relation to monoamine oxidase inhibitors which can cause hypertensive crises.

Laboratory Interactions

• Discussion on how abnormal plasma or serum electrolyte concentrations (e.g., potassium levels) can affect drug therapies.

Photosensitivity and Its Effects

Photosensitivity Reactions

• Explanation of drug-induced photosensitivity as a skin reaction caused by UV exposure interacting with certain drugs.

• Distinction made between phototoxicity (not immune-mediated reactions causing cellular damage from UV light activation of drugs) versus photoallergy (involving immune system responses).

Teratogenic, Mutagenic, and Carcinogenic Effects

Teratogenic Effects

• Definition provided for teratogens—compounds causing structural defects during fetal development.

Mutagenic Effects

• Description of mutagens as agents causing permanent changes in genetic composition through alterations in chromosome structure or DNA codes.

Carcinogenic Effects

• Overview of carcinogens including radiation and chemotherapy agents that may induce cancerous changes.

Toxicology Overview

Clinical Toxicology

• Introduction to toxicology as the study of poisons; clinical toxicology focuses specifically on care for poisoned patients from various causes including overdoses or ingestion of harmful substances.

Poison Control Centers

Understanding Drug Action and Therapy

Key Determinants of Drug Therapy

• The discussion emphasizes the importance of understanding various determinants that affect drug therapy, including clinical factors, administration methods, pharmacokinetics, and pharmacodynamics.

• A supplementary resource is mentioned to aid in comprehending these concepts throughout the textbook.

• A diagram summarizing the lessons on drug action is referenced, indicating a visual representation of the discussed topics.

• The speaker expresses hope that the audience has grasped the key points from their discussion regarding drug therapy determinants.