Pharmacology Chapter 3 Flashcards

Pharmacology Overview

• Pharmacology integrates multiple medical sciences including chemistry, biochemistry, anatomy, physiology, and microbiology.
• It involves the study of drugs, including their actions, dosages, therapeutic uses, and adverse effects.

Drug Therapy

• Drug therapy is closely related to the disease's pathophysiology.
• Drugs can originate from natural sources like plants, animals, and microorganisms or be synthesized.

Drug Functions

• Drugs can promote healing (e.g., anti-inflammatories), cure diseases (e.g., antibacterials), control or slow disease progress (e.g., chemotherapy), and prevent diseases (e.g., vaccines).
• They can influence neurotransmission (e.g., antidepressants), decrease complication risks (e.g., anticoagulants), enhance function and comfort (e.g., analgesics), provide replacement therapy (e.g., insulin, estrogen), and reduce excessive bodily activity (e.g., proton pump inhibitors).

Pharmacodynamics & Pharmacokinetics

• Pharmacodynamics focuses on how drugs exert their effects.
• Pharmacokinetics studies the movement of drugs within the body based on the routes of administration.

Pharmacotherapeutics & Toxicology

• Pharmacotherapeutics involves using medications to prevent or treat diseases.
• Toxicology examines the body’s reactions to drugs, focusing on both harmful and beneficial effects.

Pharmacy Practice

• Pharmacy encompasses the preparation, dispensing, and management of drug use for safe and effective patient care.

Drug Classifications

• Drugs are classified based on their primary pharmacologic actions and effects.

Indications and Contraindications

• Indications refer to approved uses of drugs for specific conditions.
• Contraindications are specific scenarios where a drug should not be used.

Side Effects and Adverse Reactions

• Side effects are mild undesirable effects that may occur even at recommended doses.
• Adverse effects can be dangerous, cause significant harm, or even be life-threatening.

Unique Drug Reactions

• Hypersensitivity relates to allergic reactions; reactions may vary from mild to severe (anaphylaxis).
• Idiosyncratic reactions are unusual responses that differ from typical drug effects.
• Iatrogenic effects are negative outcomes associated with drug administration.
• Teratogenic effects refer to developmental defects caused by drug exposure to a fetus.

Drug Interactions

• Interactions modify drug effects when combined with other drugs.
• Synergism occurs when combined drugs produce a greater effect than the sum of individual effects.
• Antagonism results in diminished effects when drugs are combined.
• Potentiation happens when one drug enhances the effect of another.

Dosing Considerations

• Dosage is the amount of drug required for the desired effect, calculated by weight, measure, and frequency.
• Children's doses are determined primarily by weight, not age.
• A loading dose can be initially administered to quickly raise drug levels in the bloodstream.
• Frequency of dosing is critical to maintain effective blood levels without toxicity.

Routes of Drug Administration

• Oral medications are absorbed slowly and require processing by the liver.
• Sublingual medications are absorbed immediately under the tongue.
• Parenteral (injection) routes vary in absorption speed: subcutaneous (slow), intramuscular (moderate), and intravenous (immediate).
• Inhalation provides rapid absorption directly into the respiratory tract.
• Topical preparations can have varying speeds of absorption, with mucous membranes absorbing more quickly than skin.

Drug Absorption and Metabolism

• Drugs are generally metabolized in the liver and excreted by the kidneys, though some can be expelled through bile or feces.
• Barriers, such as the blood-brain barrier and placental barrier, can impede drug absorption.

Drug-Receptor Interaction

• Drug actions typically involve interactions with specific receptors.
• Drugs may directly stimulate or block receptors, influencing cellular functions and biochemical processes.

Legal and Regulatory Context

• Prescriptions must include patient and prescriber information, drug details, dosage, and usage instructions.
• Generic names identify drugs uniquely, while trade names are manufacturer-specific. Chemical names specify the drug's chemical structure.
• The FDA regulates drug production, labeling, and distribution; scheduled drugs are monitored for abuse potential, while OTC drugs are available without prescriptions.

Abbreviation Guide

• PO: orally by mouth
• IM: intramuscularly
• SQ: subcutaneously
• BID: twice a day
• TID: three times a day
• QID: four times a day
• IV: intravenous
• OD: right eye
• OS: left eye
• OU: both eyes
• QD: daily
• Q 4 hr: every 4 hours
• HS: at bedtime
• ac: before meals
• pc: after meals
• prn: as needed