drug interactions Flashcards
what is a phase 1 reaction
CYP450 induced metabolism resulting in inserting a polar group fro renal excretion or essential production such as cholesterol and cortisol.
purpose of prodrugs
extend the dosing interval
prevent drug abuse
what are the active metabolites of capecitabine, clopidogrel, codeine, colistimethate, cortisone
fluorouracil,
N/A
morphine
colistin
cortisol
what are the active metabolites of famciclovir, fosphenytoin, isavuconazonium sulfate, levadopa
penciclovir
phenytoin
isavuconazole
dopamine
what are the active metabolites of lisdexamfetamine, prednisone, primidone, tramadol, valacyclovir, valgancyclovir
dextroamphetamine
rprednisolone
phenobarbital
n/a
acyclovir
ganicyclovir
cyp inhibitros in drug interactions
Grapefruit
protease inhibitor- ritonavir
azole antifungals
cyclosporine, colbicistat
macrolides- not azithromycin
amiodarone and dronedarone
non- dhp CCBs- diltiazem and verapamil
CYP inducers
phenytoin
nicotine
phenobarbital
oxcarbamazepine
rifampin
carbamazepine (auto inducer)
st johns wort
p glycoprotein efflux pump inducers
carbamazepine
rifampin
st johns wort
phenobarbital
dexamethasone
p glycoprotein efflux pump substrates
anticoags- apixaban, edoxaban, rivorxaban, dabigatran
CV- digoxin, diltiazem, verapamil, ranolazine and carvedilol
Immunosuppressant- cyclospporine, tacrolimus, sirolimus
HCV drugs-
others- colchicine, saxagliptin
p glycoprotein efflux pump inhibitors
anti infectives- clarithromycin, itraconazole, posaconazole
CV- amiodarone, carvedilol, verapamil, diltiazem and duinidine
HIV- cobicistat, ritonavir
HCV- ledipasvir
others- cyclosporine
common CV drug interactions
amiodarone- warfarin- increase bleeding risk cyp 2c9 blocker- start warfarin at a lower dose or continue with a 30-50% lower dose and monitor INR
amiodarone- digoxin - start digoxin at lower dose (0.125) or continue with 50% lower dose monitor digoxin toxicity, HR
digoxin- loop diuretic - electrolytes monitoring, decrease or DC if renally impaired
HR- monitor with amiodarone, digoxin, BB, clonidine
statins and cyp3a4 inhibitors - lova simva and low with atorvas ( pita prava and rosuva are good)
warfarin- cyp2c9 inhibitors and inducers (monitor INR 2-3) 2.5-3.5 for mitral valve replacement.
inhibitors
CYP 3a4
valproate-lamotrigine - v decreases l causing SJS and TEN use lower dose titrate slow
MAOi- drugs that increase E/NE/DA/5HT3 - MAOi can increase all NT and using E/NE/5HT/DA can increase hypertensive crisis and serotonin syndrome - 2 week washout period except fluoxetine 5 weeks
Cyp2d6i are amiodarone fluoxetine paroxetine fluvoaximine
CYP and PGp- calcineurin/mTOR i - CNI are tacrolimus and cyclosporin Mtori is sirolimus everolimus
inducers
antiepileptic -higher lamotrigine starting kit
rifampin - monitor
CYP3A4 inducers- monitor AE
CYP2D^ UM - no codeine tramadol asin prodrugs that can increase AE
nicotine - CYP1A2 inducer, R isomer of warfarin is metabolized
CYP PGP + CNI or mTORki- monitor drug level
additive risk with serotogenic toxicity
antidepressants- SSRI, SNRI, mirtazapine trazodone
MAOi- isocarboxazid, phenelzine tranylcyprommine, selegline , rasagline , linezolid, methylene blue
Opiods- fentanyl, meperidine, methadone, tramadol, tapentadol
Triptans-
natural products- st johns wort
others- buspirone, lithium, dextromethorphan
additive risk with bleeding risk
Anticoags- warfarin, dabigatran , apixaban, edoxaban, rivoraxaban, heparin, enoxparin
antiplatelets - ASA, dipyridamole, clopidogrel, prasugrel, ticagrelor
NSAIDS- Ibuprofen., naproxen, diclofenac, indomethacin etc
SSRI, SNRI- citalopram, escitalopram, fluoxetine, paroxetine, sertraline, duloxetine, venlafaxine
natural products- garlic ginger ginko, ginsen, glucosamine vit e willow bark fish oil(high dose)
