Drug interactions

Question 1

Interactions of tetracyclines

Answer 1

Dairy products and Fe2+ salts

Question 2

Cytochrome P450-mediated metabolism

Answer 2

Family of enzymes responsible for drug clearance

Drug interactions can induce this system or inhibit it

Question 3

For patients already taking amlodipine, which statins can you prescribe ?

Answer 3

Use 10mg Atorvastatin
Pravastatin has no interaction
Use 20mg simvastatin at most
Reduce dose of simvastatin

Question 4

What is an inducing agent?

Answer 4

They increased the activity of metabolising enzymes , reducing the [drug plasma]

Effect takes weeks to occur

Question 5

Cardiovascular drug interactions

Answer 5

Warfarin and NSAIDs
Warfarin and antibiotics (especially erythromycin and ciprofloxacin)
Simvastatin and macrolides : avoid
Simvastatin and amlodipine : caution of statin dose
Clopidogrel and some PPIs