pharmacy 1

Proper Utilization of PDR and Drug Handbook

• PDR (Physician's Desk Reference): A comprehensive resource intended for healthcare professionals, particularly for safe medication practices.

  • Contains drug listings including:

  • Chemical name

  • Brand name(s) (trade name)

  • Generic name

  • Properties

  • Indications

  • Side effects

  • Contraindications

  • Dosages

  • Visual representations of medications

  • Can be obtained from libraries or bookstores and may be provided to physicians free of charge.

Key Terms

• Allergy: An adverse immune response to a substance that can cause symptoms such as hives, dyspnea, or wheezing.

• Anaphylaxis: A severe, potentially life-threatening allergic reaction that requires immediate medical attention.

• Antagonism: A drug interaction where one drug decreases the effect of another drug.

• Chemical Name: The scientific name that identifies the chemical composition of a drug.

• Contraindications: Specific situations or conditions that indicate the use of a drug could be harmful.

• Drug: Any substance that causes a physiological change in the body.

• Generic Name: The non-proprietary name given to a drug that is usually lower-cased and indicates its chemical makeup.

• Interactions: The ways in which two or more drugs can affect each other's effects in the body.

• Pharmacodynamics: The study of the physiological effects of drugs on the body.

• Pharmacokinetics: The study of how drugs are absorbed, distributed, metabolized, and excreted in the body.

• Pharmacology: The scientific study of drugs, including their properties and effects.

• Potentiation: An interaction wherein one drug increases the effectiveness of another.

• Side Effect: A secondary effect of a medication that may be undesirable but is often expected.

• Synergism: An interaction wherein two drugs work together to produce an enhanced effect.

• Trade Name: The brand name under which a drug is marketed and sold.

Understanding Drug Nomenclature

• Drug Naming Conventions: Each drug has three distinct names:

  1. Chemical Name:

  • E.g., 7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one

  1. Trade Name: (Registered trademark)

  • E.g., Valium™

  1. Generic Name:

  • E.g., Diazepam

• Commercial Aspects:

  • Trade names are registered with the U.S. Patent Office and can only be used by the original manufacturer until the patent expires.

  • After expiration, other companies can produce generic equivalents, which will generally use lowercase letters.

Classification of Drugs

• Drug Classes: Drugs can be classified by their therapeutic effects and their mechanisms of action.

  • Examples:

  • Adrenergic blocking agents

  • Analgesics

  • Antibiotics

  • Anticoagulants

  • Sedatives

• Therapeutic Classification:

  • Describes the intended purpose of the drug (e.g., cardiotonic, antiarrhythmic).

Legal Regulations in Pharmacology

• FDA Regulations:

  • Enacted to protect consumers and ensure drug safety.

  • Key Acts:

  • 1906 Pure Food and Drug Act: Initial regulatory framework.

  • 1938 Federal Food, Drug, and Cosmetic Act: Required safety testing before public distribution.

  • 1952 Durham-Humphrey Amendment: Established prescription requirements for certain drugs.

  • 1962 Kefauver-Harris Amendment: Mandated efficacy testing for medications.

• Controlled Substances Act (1970):

  • Regulates manufacturing and distribution of drugs prone to abuse and dependency.

  • Controlled substances categorized into schedules (I-V) based on potential for abuse:

  • Schedule I: No accepted medical use and high potential for abuse.

  • Schedule II: High potential for abuse with accepted medical use, strict prescription rules.

  • Schedule V: Lower potential for abuse, can be refilled up to five times in six months.

Pharmacodynamics

• Definition: The study of how drugs interact with the body.

  • All drugs lead to chemical and physiological changes.

  • Types of Effects:

  • Local Effects: Limited to the area where applied (e.g., topical ointments).

  • Systemic Effects: Effects throughout the body, absorbed into the bloodstream and distributed (e.g., antibiotics).

• Factors Influencing Drug Action:

  • Age: Elderly may metabolize medications slower; children may respond more sharply.

  • Weight: Dosages often adjusted according to weight.

  • Sex: Hormonal levels and body composition may result in varying reactions to drugs.

  • Health Conditions: Diseases may alter drug metabolism and effects.

  • Tolerance: Extended use of drugs may require higher doses due to decreased effectiveness over time.

Pharmacokinetics

• Definition: Studies the movement of drugs within the body including:

  1. Absorption: How the drug enters the bloodstream.

  2. Distribution: Movement from blood to tissues.

  3. Metabolism: The breakdown of drugs, typically by the liver.

  4. Excretion: Removal of drugs (or their byproducts) from the body, primarily through the kidneys.

• Implications: Monitoring is crucial especially in patients with liver or kidney dysfunctions to avoid toxicity.

Drug Actions and Interactions

• Food-Drug Interactions: Certain medications are best absorbed on an empty stomach while others require food to mitigate side effects.

  • Example:

  • Ampicillin needs to be taken on an empty stomach.

  • Ibuprofen should be taken with food.

• Drug Interactions: Risk of interactions that can enhance or diminish drug effects, including:

  • Synergism: Combined effect is greater than individual effects.

  • Antagonism: Drug effects diminish when given together.

  • Potentiation: One drug prolongs or exaggerates the effect of another drug.

Side Effects and Allergies in Drug Administration

• Distinguishing Allergies from Side Effects:

  • Drug Allergy: Life-threatening responses requiring immediate attention; documented clearly in patient records.

  • Side Effects: Expected reactions that might occur, generally not life-threatening (e.g., drowsiness).

• Monitoring Patient Reactions: Patients should wait in-office post-injection or medication administration to monitor for allergic reactions.

Sources of Information for Drug Safety

• Utilize reliable resources for up-to-date drug information, including:

  1. PDR

  2. USPDI (U.S. Pharmacopeia Dispensing Information)

  3. AHFS (American Hospital Formulary Service)

  4. Compendium of Drug Therapy

• These resources provide vital information on drug properties, contraindications, and appropriate usage for healthcare providers.

Prescribing Medications

• Types of Medication Orders:

  • Administered in-office

  • Dispensed for future use

  • Prescribed with appropriate protocols

• Instructions for Writing a Prescription:

  • Must include physician's signature, patient's details, medication name, dosage, and instructions.

  • Important to document prescriptions in patient records to maintain legal integrity.

• Refilling Prescription Protocol:

  • Standard procedure generally requires a patient appointment for controlled substances.

  • Emergency refills require physician verification before calling into pharmacies.