Pharmacology Basics

What is a 'mechanism of action' in pharmacology?

• AHow quickly a drug is absorbed
• BHow a drug produces its therapeutic effect at the cellular/molecular level✓
• CThe side effects of a drug
• DHow the body eliminates the drug

Answer: Mechanism of action describes how a drug works at a molecular level to produce its therapeutic effect (e.g., blocking an enzyme, activating a receptor).

Which of the following best describes 'bioavailability'?

• AThe total amount of drug in the body
• BThe fraction of an administered drug dose that reaches systemic circulation unchanged✓
• CHow quickly a drug works
• DThe cost-effectiveness of a drug

Answer: Bioavailability (F) is the proportion of an administered dose that reaches systemic circulation. IV drugs have 100% bioavailability.

What is 'drug interaction'?

• AWhen two patients take the same drug
• BWhen one drug affects the action of another drug, potentially increasing or decreasing its effect✓
• CAllergic reaction to a drug
• DSide effects of a single drug

Answer: A drug interaction occurs when one medicine affects another's absorption, metabolism, or effects, potentially increasing toxicity or reducing efficacy.

Which of the following is an example of a drug acting as an ACE inhibitor?

• AMetformin
• BLisinopril✓
• CAmlodipine
• DAtenolol

Answer: ACE inhibitors block angiotensin-converting enzyme, reducing blood pressure. Examples include lisinopril, enalapril, and ramipril.

What does 'half-life' mean in pharmacology?

• AHalf the dose needed
• BThe time taken for the drug concentration to reduce to half its original level✓
• CHow long the drug lasts
• DHalf the population taking the drug

Answer: Half-life (t½) is the time for plasma concentration to fall by 50%. It helps determine dosing intervals and accumulation.

Which of the following is a beta-blocker used in cardiovascular disease?

• ALisinopril
• BAmlodipine
• CAtenolol✓
• DRamipril

Answer: Beta-blockers (e.g., atenolol, propranolol, bisoprolol) block beta-adrenergic receptors, reducing heart rate and blood pressure.

What is a 'side effect' or 'adverse effect'?

• AThe main therapeutic action of a drug
• BAn unwanted effect of a drug that occurs in addition to its therapeutic effect✓
• CAn allergic reaction
• DDrug resistance

Answer: Side/adverse effects are unwanted effects occurring alongside the therapeutic action (e.g., nausea from antibiotics).

What is 'contraindication'?

• AA side effect
• BA situation or condition in which a medicine should NOT be used due to risk of harm✓
• CAn indication for use
• DA drug interaction

Answer: A contraindication is a condition or factor that makes a particular treatment inadvisable (e.g., ACE inhibitors contraindicated in pregnancy).

Which class of drug is used to treat bacterial infections?

• AAntihistamines
• BAntibiotics✓
• CAntivirals
• DAntifungals

Answer: Antibiotics (e.g., penicillins, cephalosporins, macrolides) are used to treat bacterial infections by killing or inhibiting bacteria.

What is 'pharmacokinetics'?

• AHow a drug works in the body
• BWhat the body does to the drug (absorption, distribution, metabolism, excretion)✓
• CDrug side effects
• DAllergic reactions

Answer: Pharmacokinetics describes ADME: how the body absorbs, distributes, metabolizes, and excretes drugs.

What is 'pharmacodynamics'?

• AHow the body eliminates drugs
• BHow drugs are absorbed
• CWhat the drug does to the body (how it produces its effect)✓
• DDrug interactions

Answer: Pharmacodynamics describes the effect of drugs on the body—their mechanism of action and relationship between dose and response.

Which of the following is a proton pump inhibitor used for acid reflux?

• ARanitidine
• BOmeprazole✓
• CAntacid
• DDomperidone

Answer: Proton pump inhibitors (PPIs) like omeprazole block gastric acid production. Other PPIs include lansoprazole and pantoprazole.