Drug drug interactions Flashcards
1
Q
What are the 2 types of DDI?
A
- Pharmacdynamic interactions (in terms of therapeutic effect)
- Pharmacokinetic interactions
2
Q
What do pharmacokinetic interactions effect?
A
- Drug Absorption
- Drug-plasma protein binding
- Drug metabolism – most common! (P450s)
- Drug transport
- Renal excretion
3
Q
What are the interactions that cause metabolic DDIs?
A
Inhibition or induction of CYP enzymes, often associated with CYP3A4
4
Q
What effect could a weak DDI in a drug with a narrow therapeutic window have?
A
BIG effect (e.g. digoxin)
5
Q
What is induction?
A
Increased synthesis or activity of metabolic enzymes:
- slow effect, involves enzyme turnover
- can lead to lack of therapeutic effect - higher elimination
6
Q
What is inhibition?
A
Inactivation or less enzyme available. Two types: reversible and irreversible
