Basic Pharmacology for Nursing Students: Drugs, Actions, and Safety

What is pharmacology?

The study of drugs and their effects on the body, including actions, uses, side effects, and safety.

What is the goal of pharmacotherapeutics?

To achieve maximum benefit with minimal harm when using medications to treat, prevent, or diagnose disease.

What are adverse effects in pharmacology?

Undesirable or potentially dangerous effects of drugs that nurses must monitor.

Name a plant-derived drug.

Digoxin, morphine, or opium.

What is a common animal-derived drug?

Insulin.

What are synthetic drugs?

Drugs produced in laboratories, often through genetic engineering of bacteria.

What are controlled substances?

Drugs regulated due to their potential for abuse, classified into schedules I-V by the DEA.

What is the classification of Schedule I drugs?

High abuse potential, no accepted medical use (e.g., heroin).

What defines Schedule II drugs?

High abuse potential with severe dependence (e.g., narcotics, amphetamines).

What is the difference between a generic name and a brand name of a drug?

The generic name is the official drug name, while the brand name is the manufacturer's name.

What does 'Dispensed As Written' (DAW) mean?

A directive to dispense the prescribed drug exactly as written, important for drugs with narrow safety margins.

What are over-the-counter (OTC) drugs?

Medications available without prescription that can still cause side effects and interactions.

What is pharmacodynamics?

The study of what a drug does to the body, including drug-receptor interactions.

What is the role of an agonist in pharmacology?

A drug that binds to a receptor and activates it, producing a biological response.

Give an example of an agonist.

Morphine, which binds to opioid receptors in the CNS to decrease pain perception.

What is an antagonist?

A drug that binds to a receptor but does not activate it, blocking the receptor and preventing agonists from working.

What does cholinergic refer to?

Nerves or drugs that use acetylcholine (ACh), the primary neurotransmitter of the parasympathetic nervous system.

What are muscarinic receptors?

Cholinergic receptors located in the heart, smooth muscle, and glands, primarily affecting the parasympathetic system.

What is the primary effect of nicotinic receptors?

Muscle contraction when stimulated, located at the neuromuscular junction and autonomic ganglia.

What are the primary actions of epinephrine at α₁ receptors?

Vasoconstriction, which increases blood pressure.

What is the primary action of epinephrine at β₁ receptors?

Cardiac stimulation, which increases heart rate and cardiac output.

What is the primary action of epinephrine at β₂ receptors?

Bronchodilation, which opens airways.

What does ADME stand for in pharmacokinetics?

Absorption, Distribution, Metabolism, Excretion.

What is drug absorption?

The process by which a drug moves from its site of administration into the bloodstream.

What factors affect drug absorption?

Route of administration, drug formulation, blood flow at the site, surface area, and first-pass effect.

What is the first-pass effect?

The metabolism of a drug in the liver before it reaches systemic circulation, which can reduce the amount of active drug.

What influences drug distribution in the body?

Blood flow to tissues, plasma protein binding, and fat solubility.

What is the blood-brain barrier?

A protective barrier that allows only lipid-soluble drugs or those with special transport mechanisms to cross into the brain.

What is the goal of drug metabolism?

To chemically alter a drug to make it easier to eliminate, usually by converting it to a water-soluble form.

What is the primary goal of metabolism?

To make the drug easier to eliminate, usually by turning it into a water-soluble form that can be excreted in urine or bile.

What are the two phases of drug metabolism?

Phase I (Functionalization Reactions) and Phase II (Conjugation Reactions).

What happens during Phase I of drug metabolism?

The drug is chemically changed through oxidation, reduction, or hydrolysis.

Which enzyme system is key in Phase I metabolism?

The cytochrome P450 enzyme system in the liver.

Give an example of a drug converted in Phase I metabolism.

Codeine is converted into morphine.

What occurs during Phase II of drug metabolism?

The drug or its metabolite is combined with another substance to make it inactive and more water-soluble.

Why is oral nitroglycerin given sublingually?

Because it is inactivated by the first-pass effect when taken orally.

What are prodrugs?

Drugs that are inactive until metabolized into their active form by the liver.

Provide an example of a prodrug.

Codeine, which is metabolized to morphine for pain relief.

What are enzyme inducers?

Substances that speed up metabolism, leading to decreased drug levels.

What are enzyme inhibitors?

Substances that slow down metabolism, increasing the risk of drug toxicity.

How does age affect drug metabolism?

Infants have immature livers (slower metabolism), and the elderly often have reduced liver function.

What is the most common route of drug excretion?

Renal (Kidneys → Urine).

What factors affect drug excretion?

Renal function, urine pH, and the drug's solubility.

What is the half-life of a drug?

The time it takes for the concentration of the drug in the body to be reduced by 50%.

How is steady state achieved?

Usually after about 4-5 half-lives, when drug intake equals drug elimination.

What is drug toxicity?

Occurs when drug levels are too high, often due to overdose or accumulation.

What is selective toxicity?

The ability of a drug to target harmful cells while minimizing damage to healthy cells.

What are teratogens?

Substances that can cause harm to a developing fetus, especially during the first trimester.

What is a drug allergy?

An immune system reaction to a medication that can occur even with small doses.

What are the types of adverse effects?

Primary actions, secondary actions, and hypersensitivity reactions.

What should nurses do regarding medication safety?

Verify orders, check allergies, and monitor high-alert medications closely.

What are the rights of medication administration?

Right patient, right medication, right dose, right route, right time, right documentation, right reason, and right response.

What is the nursing process in medication administration?

Assessment, diagnosis, planning, implementation, and evaluation.