Introduction to Pharmacology

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Questions and Answers

What defines a drug allergy?

An improper use of common medications

An immunological or hypersensitive reaction to a drug (correct)

A continuous intake of a substance

A psychological dependence on substances

What is the difference between drug misuse and drug abuse?

Drug misuse usually involves over-the-counter drugs, while abuse involves illegal drugs.

Drug misuse is the improper use of medications, whereas drug abuse refers to inappropriate intake of substances. (correct)

Drug misuse is only associated with alcohol, while drug abuse includes all other substances.

Drug misuse involves emotional reliance, while abuse involves physical reliance.

Which route of drug administration is associated with a faster absorption rate compared to others?

Intramuscular route (correct)

Sublingual route

Subcutaneous route

Gastric mucosa

Which type of drug dependence is characterized by biochemical changes in the body?

Physiological dependence Signup and view all the answers

What factor can enhance the absorption of Griseofulvin?

Fatty meal Signup and view all the answers

What is drug tolerance?

The need to increase the drug dose due to biochemical changes in the body Signup and view all the answers

What is the effect of the first-pass metabolism on drugs?

It destroys some drugs before they reach systemic circulation. Signup and view all the answers

Which of the following best describes an illicit drug?

Street drugs that are sold illegally Signup and view all the answers

Which type of drugs is primarily absorbed in the stomach due to their weak acidic nature?

Weak acidic drugs Signup and view all the answers

Which form of drug is absorbed more efficiently, according to the pharmaceutical form?

Solutions Signup and view all the answers

What increases the bioavailability of all drugs when consumed?

Grape juice Signup and view all the answers

How can the first-pass effect be overcome?

By increasing the oral dosage. Signup and view all the answers

Which statement accurately describes bioavailability?

It is the percentage of drug reaching systemic circulation unchanged. Signup and view all the answers

What is a disadvantage of self-medication?

It is inconvenient and can be difficult. Signup and view all the answers

Which of the following medications is administered through inhalation for bronchial asthma?

Salmeterol Signup and view all the answers

What is one method of transcutaneous drug administration?

Jet injection Signup and view all the answers

Which of the following drugs can be administered via the sublingual route?

Diazepam Signup and view all the answers

What can be a consequence of drugs absorbed through inhalation?

They may directly affect cardiac tissue. Signup and view all the answers

What is the definition of a drug according to WHO?

Any substance used to modify or explore physiological systems for the benefit of the recipient. Signup and view all the answers

What does pharmacokinetics study?

The absorption, distribution, metabolism, and excretion of drugs. Signup and view all the answers

Which of the following describes pharmacodynamics?

The study of the body's effect on drugs. Signup and view all the answers

What is a side effect of a drug?

An unintended secondary effect of the drug. Signup and view all the answers

What is the primary focus of chemotherapy?

Drug treatment of cancer and microorganisms. Signup and view all the answers

What is meant by drug toxicity?

The harmful effects of a drug on an organism or tissue. Signup and view all the answers

What is the role of a pharmacopoeia?

To contain descriptions of established drugs and their properties. Signup and view all the answers

What does a formulary provide to its subscribers?

Information about available drugs based on expert recommendations. Signup and view all the answers

Which source of drugs includes Monoclonal Antibodies?

Hybridoma Technique Signup and view all the answers

What is a major disadvantage of the oral route of drug administration?

Slow onset of drug action Signup and view all the answers

Which of the following is NOT a mineral source of drugs?

Morphine Signup and view all the answers

What type of drug administration route includes the use of dusting powder?

Local application Signup and view all the answers

Which drug is destroyed by digestive juices and cannot be administered orally?

Insulin Signup and view all the answers

Which of these substances is classified as a synthetic source of drugs?

Analgesics Signup and view all the answers

Which of the following is NOT an example of a parenteral route of drug administration?

Buccal tablets Signup and view all the answers

What purpose do enteric coated tablets serve?

They protect the drug from being destroyed in the stomach. Signup and view all the answers

What is the primary purpose of enteric coating on tablets?

To prevent gastric irritation and alteration of the drug Signup and view all the answers

Which route of administration allows for the injection of larger volumes, such as fluids in shock?

Intravenous Signup and view all the answers

What type of substances can be injected subcutaneously?

Non-irritant substances Signup and view all the answers

Which intramuscular injection site is recommended for administering medications?

Gluteus maximus Signup and view all the answers

What is a potential disadvantage of intravenous drug administration?

Action cannot be halted once administered Signup and view all the answers

Which route of drug administration is specifically used for direct introduction into the spinal cord?

Intra-thecal Signup and view all the answers

What makes parenteral drug administration particularly useful for unconscious patients?

It ensures rapid and accurate dosing. Signup and view all the answers

What is a common use for intra-peritoneal drug administration?

To provide normal saline in infants Signup and view all the answers

Study Notes

Introduction and General Pharmacology

Pharmacology is the study of drugs, particularly their actions on animals, organs, and tissues
Treatments in early times involved flesh, blood, excreta of animals, plant, and metal preparations
A drug is any substance or product used to modify or explore physiological systems or pathological states for the recipient's benefit (WHO definition)
Drugs are derived from the word "drogue," meaning herb.

Types of Medications

Medication: A substance used for diagnosis, cure, treatment, mitigation, or prevention.
Prescription: Written directions for drug preparation and administration.
Therapeutic effect: Intended primary effect of a drug. (e.g., morphine sulfate is analgesia)
Side effect: Unintended secondary effect of a drug. (e.g., diarrhea with Mg-Antacids)

Pharmacokinetics

Pharmacokinetics: The study of absorption, distribution, metabolism, and excretion of drugs, and their relation to the pharmacologic response.
Pharmacodynamics: A quantitative study of biological and therapeutic effects of drugs (how the drug impacts the body).
Poisons: Substances that cause harm, danger, or death in animals or humans.
Chemotherapy: The effect of drugs on microorganisms and parasites, including cancer treatment.

Drug Codes and Information Sources

Pharmacopoeia: An official code with a selected list of established drugs and preparations, describing physical properties, purity, and potency.
Formulary: Provides information on available drugs based on sources and expert recommendations.

Drug Toxicity, Allergy, and Interactions

Drug toxicity: Deleterious effect on an organism or tissue due to overdose or external use.
Drug allergy: Immunological reaction or hypersensitivity to a drug (e.g., penicillin hypersensitivity).
Drug interaction: Effects of administering one drug before or after another, sometimes altering their effects. (e.g., caffeine and Alprazolam show no interaction)

Drug Abuse and Dependence

Drug abuse: Inappropriate intake of a substance, occasional or continual. (e.g., alcohol abuse).
Drug dependence: A person's reliance or need to take a drug or substance.
- Physiological dependence: Due to biochemical changes in the body tissue, needing the substance for normal function (e.g., heroin dependence)
- Psychological dependence: Emotional reliance on a drug to maintain well-being with a feeling of need (e.g., nicotine dependence)

Drug Tolerance, Habituation, and Illicit Drugs

Drug tolerance: Body tissue changes causing the body to require increasing doses for normal function. (e.g., Marijuana usage may cause tolerance).
Drug habituation: A mild form of psychological dependence. (e.g., habituation to cigarettes).
Illicit drugs: Drugs sold illegally (e.g., cocaine)

Various Names of Drugs

Generic name: A shortened version of a drug's chemical name, structure, or formula.
Official name: Name used in official publications.
Chemical name: Name used by chemists.
Trade name: Name given by the manufacturer (e.g., Esidrex).

The Nature and Sources of Drugs

Mineral sources: Liquid paraffin, magnesium sulfate, magnesium trisilicate, kaolin
Animal sources: Insulin, thyroid extract, heparin, gonadotropins, anti-toxic sera
Plant sources: Morphine, digoxin, quinine, atropine, reserpine
Micro-organism sources: Antibiotics like penicillin, Polymixin B
Synthetic sources: Analgesics, hypnotics, anti-cancer agents, antimicrobials
Genetic engineering: Insulin, growth hormone
Hybridoma Technique: Monoclonal antibodies

Routes of Drug Administration

Local application: For topical use (e.g., ointments)
Oral route: Administration through the mouth (e.g., pills, tablets).
Parenteral route: Administration other than through the mouth via injection (intramuscular, intravenous etc).
Intradermal: Into the layers of the skin (e.g., BCG vaccine).
Subcutaneous: Under the skin (e.g., Insulin, sex hormone implants).
Intramuscular: Into muscle tissue (e.g., diazepam).
Intravenous: Into veins (e.g., large volume fluids).
Intra-arterial: Into arteries (Used in diagnostic studies)
Intra-thecal: Drugs directly into the spinal cord membranes (e.g., spinal anesthesia.)
Intra-peritoneal: Into peritoneal cavities (e.g., infant saline administration).
Intraosseous cannulation: Into the bone, often used in shock cases (e.g., adrenaline).
Inhalations: Administration via vapors or aerosol (e.g., pressurized metered dose aerosols, dry powders, or nebulized solutions).
Transcutaneous: Across the skin (e.g., iontophoresis).
Sublingual: Under the tongue (e.g., nitroglycerin).
Trans nasal: Through the nose (e.g., vasopressin).
Trans rectal: Into the rectum (e.g., aminophylline).
Endo-tracheal: Into the trachea (after dilution) (e.g., adrenaline).

Enteric Coated Pills and Tablets

Enteric-coated tablets dissolve in the intestine, not the stomach, to avoid stomach irritation.

Pharmacokinetics (ADME)

Absorption: Drugs moving from administration site to systemic circulation
Factors influencing absorption: Physico-chemical properties of drugs, pharmaceutical form of the drug, pH of the gut, rate of dissolution, presence of other substances, first pass effect
First pass effect: Drugs metabolized by the liver during initial passage, thus reducing bioavailability (e.g., Proponolol)
Oral bioavailability: Percentage of the drug that reaches the systemic circulation after oral administration.

Factors Modifying Dosage and Action of Drugs

Age: Infants are more susceptible to drug effects due to underdeveloped enzyme systems. Lower dose required according to age and weight.
Sex/Gender: Women generally need lower doses than men (Fat content and hormone differences).
Women may have greater sensitivity or different reactions to certain drug types. Prescriptions should be individualized.

Routes of Administration and Their Impacts

Administration routes affect the drug's action. Magnesium sulfate is a purgative when administered orally, and dehydrating agent when administered rectally.

Drug Intolerance and Tolerance

Drug Intolerance: Decrease drug dose due to super-sensitivity.
Drug Tolerance: Failure to respond to a drug.
Can be congenital (genetic) or acquired (due to repetitive use).

Types of Tolerance, Hypersensitivity, and Idiosyncrasy

Tachyphylaxis:Rapidly diminishing response to successive doses of a drug.
Cross-tolerance: Tolerance between related drugs.
Hypersensitivity: Exaggerated immune response to a drug (Allergic reaction).
Idiosyncrasy: Abnormal response to a drug due to genetic or enzyme factors (e.g., peripheral neuritis)

Drug Dependence and Addiction

Habituation/dependence: Emotional or psychological dependence on the drug, emotional distress if stopped.
Addiction: A state of psychic craving for or physiological dependence on a drug. Intense withdrawal symptoms if stopped.

Pathological State Affecting Drug Effects

Patient's condition affects drug actions. Aspirin lowers temperature to normal, but not below normal.

Drug Accumulation and Adverse Drug Reactions

Drug accumulation: When drug administration rate exceeds elimination, leading to adverse reactions.
Adverse Drug Reactions: Unwanted medical responses to a drug.
- Predictable (Type A): Dose dependent, related to drug action.
- Unpredictable (Type B): Dose independent, due to genetic or enzyme factors.
- Continuous (Type C): Long-term use leading to cell or organ damage.
- Delayed (Type D): Effects showing up after prolonged use.
- Withdrawal (Type E): Effects when drug use is stopped suddenly.

Drug Combinations

Combining different drugs may affect their actions
Addition/Summation (1+1=2)
Synergism (1+1=3)
Potentiation (1+1=2)
Antagonism (1+1=0)

Drug Classification: Adverse Effects

Provides a useful way to classify drug effects, recognizing the different types of adverse reactions and how they manifest based on dose, timing and origin.

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Description

This quiz covers the fundamentals of pharmacology, including the definition of drugs, types of medications, and an overview of pharmacokinetics. Understand the therapeutic effects, side effects, and historical context of drug use. Test your knowledge in this essential field of study.