Master Drug Interactions in Medicinal Chemistry for MPharm Students

Question 1

Which enzyme family predominantly participates in the cytochrome P450 pathway?

Accepted Answer

Cytochrome P450 enzymes (CYP450)

Answer

Acetylcholinesterases

Answer

Lipoxygenases

Answer

UDP-glucuronosyltransferases

Question 2

Identify the primary mechanism by which drug interactions commonly occur:

Accepted Answer

Interference with drug metabolism

Answer

Alteration of protein binding

Answer

Direct displacement from receptors

Answer

Chemical interactions forming inactive compounds

Question 3

Which of the following is NOT a recognized adverse outcome associated with drug interactions?

Accepted Answer

Development of antimicrobial resistance

Answer

Enhanced drug toxicity

Answer

Reduced drug effectiveness

Answer

Emergence of new or unexpected adverse effects

Question 4

Describe the primary function of cytochrome P450 enzymes in relation to drug interactions:

Accepted Answer

They metabolize drugs, influencing their clearance and disposition

Answer

They bind to drugs, preventing their absorption

Answer

They facilitate drug transport across biological membranes

Answer

They convert inactive prodrugs into their active forms

Question 5

Identify a drug known for its potent inducing effect on CYP3A4, an enzyme responsible for drug metabolism:

Accepted Answer

Rifampin

Answer

Erythromycin

Answer

Phenytoin

Answer

Cimetidine

Question 6

Consider the potential interaction between warfarin, an anticoagulant, and aspirin, an antiplatelet medication:

Accepted Answer

Increased risk of bleeding due to synergistic anticoagulant effects

Answer

Reduced anticoagulant effect of warfarin, diminishing its effectiveness

Answer

Enhanced antiplatelet activity of aspirin, leading to increased risk of bleeding

Answer

Reduced gastrointestinal irritation associated with aspirin use

Question 7

Identify a potential drug-herb interaction involving St. John's wort, a commonly used herbal supplement:

Accepted Answer

Increased metabolism of oral contraceptives, reducing their efficacy

Answer

Enhanced anticoagulant effect of warfarin, increasing the risk of bleeding

Answer

Reduced absorption of digoxin, a cardiac medication

Answer

Increased seizure risk when taken with anticonvulsant medications

Question 8

Which medication is known to induce cytochrome P450 enzymes, potentially leading to lower plasma concentrations of concurrently administered drugs?

Accepted Answer

Phenytoin

Answer

Amiodarone

Answer

Cimetidine

Answer

Warfarin

Question 9

Which food component has the potential to interact with medications, affecting their absorption or metabolism?

Accepted Answer

Grapefruit juice

Answer

Dairy products

Answer

Green leafy vegetables

Answer

Red meat

Question 10

What is the function of drug interaction databases in clinical practice?

Accepted Answer

Providing information on potential drug interactions

Answer

Assessing the severity of drug interactions

Answer

Suggesting alternative drug regimens

Answer

Monitoring patients for adverse effects

Question 11

The interaction between grapefruit juice and felodipine is an example of a:

Accepted Answer

Pharmacokinetic interaction

Answer

Pharmacodynamic interaction

Answer

Synergistic interaction

Answer

Antagonistic interaction

Question 12

Which enzyme is primarily responsible for the metabolism of drugs?

Accepted Answer

CYP3A4

Answer

CYP2D6

Answer

UGT1A1

Answer

MAO-A

Question 13

What is the first step in managing drug interactions?

Accepted Answer

Identifying potential interactions

Answer

Adjusting drug doses

Answer

Monitoring patients for adverse effects

Answer

Discontinuing one of the interacting drugs

Question 14

What is the term for a drug interaction that results in a greater-than-additive effect?

Accepted Answer

Synergism

Answer

Additive

Answer

Antagonism

Answer

Potentiation

Question 15

The interaction between aspirin and warfarin is an example of:

Accepted Answer

Increased warfarin toxicity

Answer

Decreased warfarin efficacy

Answer

Synergistic interaction

Answer

Antagonistic interaction

Question 16

A patient is currently receiving warfarin and simvastatin. Explain how co-administration of these medications can increase the risk of bleeding.

Accepted Answer

Warfarin's anticoagulant effect is increased due to decreased metabolism by simvastatin.

Answer

Warfarin's anticoagulant effect is decreased due to increased metabolism by simvastatin.

Answer

Simvastatin's lipid-lowering effect is decreased due to increased metabolism by warfarin.

Answer

Simvastatin's lipid-lowering effect is increased due to decreased metabolism by warfarin.

Question 17

A patient taking warfarin is prescribed a course of antibiotics. Which antibiotic is most likely to enhance the anticoagulant effect of warfarin?

Accepted Answer

Erythromycin

Answer

Amoxicillin

Answer

Ciprofloxacin

Answer

Metronidazole

Question 18

Which component commonly found in food can reduce the absorption of tetracycline antibiotics?

Accepted Answer

Calcium

Answer

Potassium

Answer

Sodium

Answer

Vitamin C

Question 19

Approximately how long does it usually take for CYP450 enzymes to be induced after starting a new drug?

Accepted Answer

1-2 weeks

Answer

1-2 days

Answer

1-2 months

Question 20

Which of the following is NOT a type of transporter protein involved in drug interactions?

Accepted Answer

Sodium-glucose cotransporter (SGLT)

Answer

P-glycoprotein

Answer

Multidrug resistance protein (MRP)

Answer

Organic anion transporting polypeptide (OATP)

Question 21

Which drug-drug interaction poses the highest risk of causing bleeding complications?

Accepted Answer

Warfarin and aspirin

Answer

Lithium and caffeine

Answer

Metformin and alcohol

Answer

Ibuprofen and paracetamol

Question 22

For a patient using digoxin to manage heart failure, which food item should be consumed in moderation?

Accepted Answer

Grapefruit

Answer

Orange juice

Answer

Bananas

Answer

Apples

Question 23

Which herb-drug combination is known to potentially trigger serotonin syndrome?

Accepted Answer

St. John's Wort and selective serotonin reuptake inhibitors (SSRIs)

Answer

Ginkgo biloba and warfarin

Answer

Echinacea and immunosuppressants

Question 24

In the clinical management of drug interactions, which action is most appropriate?

Accepted Answer

Discontinuing or adjusting the dosage of one of the interacting medications

Answer

Increasing the dosage of both medications to counteract the interaction

Answer

Ignoring the interaction and continuing with both medications

Question 25

What is the primary function of the CYP450 enzyme system?

Accepted Answer

Drug metabolism

Answer

Drug distribution

Answer

Drug absorption

Answer

Drug excretion

Question 26

Which term describes a drug interaction where one drug reduces the effectiveness of another?

Accepted Answer

Antagonism

Answer

Potentiation

Answer

Additivity

Answer

Synergism

Question 27

What is the initial step in addressing a suspected drug interaction?

Accepted Answer

Conducting a comprehensive medication history review

Answer

Referring the patient to a specialist

Answer

Discontinuing all medications

Answer

Adjusting the dosage of all medications