Drug Interactions

Question 1

CYP enzyme inducers + what enzyme do they not induce

Answer 1

Anticonvulsants
Steroids
Antimicrobials
St John's wart
Tobacco

CYP2D6

Question 2

What foods are also inducers of CYP?

Answer 2

Grapefruit

Cranberry juice

Question 3

Reversible enzyme inducers

Answer 3

Azole antifungals, such as fluconazole and voriconazole.

Question 4

Irreversible enzyme inducers

Answer 4

Irreversible: erythromycin.

Question 5

Name a herb that interacts with antiplatelets

Answer 5

Garlic - has antiplatelet properties

Question 6

Name a herb that interacts with hypoglycemic drugs

Answer 6

Ginseng

Question 7

Name a herb that interacts with warfarin/antiplatelets

Answer 7

Glucosamine

Question 8

Effects of St John’s Wart on drugs

Answer 8

Reduces OCP levels
Increases risk of serotonin syndrome
Increases hypertensive risk with MOAi
Increases metabolism of warfarin/reduces INR

Question 9

What does pharmacokinetic interaction mean?

Answer 9

Drug interactions are those that can affect the processes by which drugs are absorbed, distributed, metabolised or excreted. (ADME of other drugs)

K = kick out

Question 10

Pharmacodynamic interactions - meaning

Answer 10

Synergistic action when two drugs are given together

Question 11

Example of pharmacodynamic interaction with NSAID

Answer 11

NSAID and warfarin

Question 12

What should be avoided if taking metronidazole?

Answer 12

Alcohol

Question 13

MOAi + tyramine rich foods - effect

Answer 13

Rise in BP

Question 14

Cranberry juice + warfarin

Answer 14

Increased effect of warfarin

Question 15

Ferrous sulfate + quinolone antibiotics

Answer 15

Reduced absorption of quinolones

Question 16

A drug that does not interact with CP450 system

Answer 16

Nifedipine

Question 17

Potent liver enzyme inducer

Answer 17

Rifampicin