Drug Interactions

Question 1

Three problems the pharmacy industry is facing

Answer 1

1. Aging population
2. Polypharmacy
3. Lifestyle (e.g. usage over the counter drugs has increased)

Question 2

What are the five risk factors faced by patients today

Answer 2

1. Polypharmacy
2. Old Age
3. Genetics
4. Hepatic Disease
5. Renal Disease

Question 3

What are three issues to consider with drugs

Answer 3

1. A narrow therapeutic drug
2. Steep dose
3. Saturable metabolism

Question 4

What five characteristics do we look for when considering the way a drug is absorbed

Answer 4

1. Motility
2. Acidity
3. Solubility
4. Complex formation
5. Direct action on enterocytes

Question 5

What main characteristic do we look for when considering how a drug is distributed

Answer 5

Protein binding

Question 6

Three mechanisms of drug metabolism

Answer 6

1. Action of CYP450
2. Inhibition
3. Induction

Question 7

Name two types of CYP450 enzymes

Answer 7

CYP1A2

CYP3A4

Question 8

Three most important classes of CYP

Answer 8

1,2,3

Question 9

Consequence of drug A blocking metabolism of drug B (inhibition drugs)

Answer 9

More drug B stays in the plasma (increased effects)

Question 10

Effect of induction drugs

Answer 10

Drug C induces CYP450 isoenzyme, leading to increased metabolism of drug D -> decreased therapeutic effects

Question 11

What CYP is effected by grapefruit juice

Answer 11

CYP3A4

Question 12

How does grapefruit juice affect CYP3A4

Answer 12

Increases bioavailability

Question 13

What drug has major interaction with Antiarrythmic agents

Answer 13

Amiodarone

Question 14

What drug has major interactions with antihistamines

Answer 14

Diphenhydramine

Terfenadine

Question 15

Minor interactions of drugs with Ca Channel antagonists

Answer 15

Nimodipine
Nicardipine
Felopdipine
Nifedipine

Question 16

Major drug interaction with Statins

Answer 16

Simvastatin

Question 17

Minor drug interaction with Statins

Answer 17

Atorvastatin

Question 18

Minor interaction drugs with immunosuppressants

Answer 18

Cyclosporin

Tacrolimus

Question 19

Two ways drugs are excreted

Answer 19

Renale

Biliary

Question 20

What factor effect renal excretion of drugs

Answer 20

pH

Question 21

When are weak bases cleared faster

Answer 21

If urine is acidic

Question 22

When are weak acids cleared fastest

Answer 22

Urine is alkaline

Question 23

Name three weak acid drugs

Answer 23

Aspirin
Ibuprofen
Warfarin

Question 24

Name there weak bases

Answer 24

Amphetamine
Atropine
Diazepam
Salbutamol

Question 25

Three characteristics of pharmacodynamics

Answer 25

Receptor based Signal transduction (beta adrenergic receptors) Physiological systems

Question 26

How do we avoid drug interactions

Answer 26

1. Rational prescription 2. BNF 3. Ward pharmacist 4. Internet 5. Medicines information service