Drug interactions Flashcards
1
Q
Enzyme inducer
A
carbamazepine barbiturates phenytoin griseolfulvin St John's Wort Rifampicin Smoking Alcohol
2
Q
Enzyme inhibitors
A
Ciprofloxacin Erythromycin Cimetidine Sodium Valproate Fluoxetine Ketoconazole Fluconazole Grapefruit juice
3
Q
Alcohol interactions
A
metronidazole = disulfiram like interaction warfarin = anticoagulant control may be affected by varying consumption MAOI = tyramine containing may result in hypertensive crisis TCAs = sedative effect
4
Q
Oral contraceptives
A
enzyme inducers increase metabolism of OCs
5
Q
Amoxicillin and doxycycline and the pill
A
may impair absorption of OC additional precautions required
6
Q
orlistat interactions
A
reduce plasma conc of amiodarone
7
Q
Pharmacokinetic interactions
A
Absorption
Changes in protein binding and distribution = one drug displaces another from a protein binding site increasing its proportion free to go to site of action (e.g. warfain >95% protein bound displaced by ?
Metabolism = amiodarone inhibits CYP2C9 increasing warfarin concentration. St John’s wort induces CYP2C9 reducing warfarin efficacy
