Drug Interactions Flashcards
name two PGP substrates?
dabigatran (pradaxa)
Rivaroxaban (xarelto)
name inhibitors of PGP
cyclosporine ketokonazole itraconzole, LPV/r IDVr erythormycin verapamil St John's wort
Pneumonic for BIG CYP450 inducers
PS PORCS pheytoin Smoking Phenobarbital Oxcarbazepine Rifampin Carbamazepine St. John's wort
Pneumonic for BIG CYP450 inhibitors
G <3 PACMAN Grapefruit P rotease inhibotrs Azole antifungals Cimetidine Macrolides except azithromycin Amiodarone Non-dihydropyridines: verapamil/ diltiazem
DDIs amiodarone
Avoid w/ agents that prolong the QT
avoid w/ neg chrnotropes: BB, diltiazem, verap
correct electrolyte abnormailities before starting
avoid GFJ
decrease the doses of these by 30-50% when using w/ amiodarone: warfarine, digoxin
use lower doses of simva, lova and atorvastatin
all azoles inhibit which enzyme?
cyp3a4
which of the azoles requires an acidic environment to be absorbed
itraconazole
ketoconazole
name contraindicated voriconazole agents
barbiturates carbamzzepine rifampin rifabutin ritonavir st johns wort
digoxin DDIs
BB, CCB can dec HR
cyp 3a4 and pgp substate
hypokalemia, hypercalcemia anc dec digxoicn levels
GFJ DDIs
statins : lova, simva, atorva
cyp 3a4 inhibitors and inducer
where is lithium primarily cleared?
renally ! just like sodium
which agents increase lithium levels?
less salt intake, NSAIDS, ACEI, ARBS, dehydration
which agents will decrease lithium levels
salt intake ,
cafene
theophylline
which have additive DDI w/ lithium
SSRIS, SNRIs Triptans, linezolid RISK OF SEROTONIN SYNDROME
what is the consequence of using non sleective MAOIs that have ddis?
Serotonin sydnrome
hypertensive crisis
death
MAOI DDIS
SSRIS, SNRIS, TCAS buporpion buispirone lithium linezolid destromethorphan, triptans tyramine rich foods etc
NSAIDS DDIS
w/ agents that cuase bleeding agents that raise blood pressure agents that causer renal toxiicty lithium (inc lithium toxicity) CV toxicity
oral contraceptives DDI
antibiotics: amp, smx/ doxy, rif (use backup while on antibiotic for rif for 1.5 months afterwards too.
- anticonfvulsants
- st johns wort (do not use concurrentlyO
- ATV, LPV, r, NFV, NVP
- mycophenylate reduces efficacy
- smoking
Oxycontin and other oxycodone products
increased levels if cyp 3a4 inhibitors
phosphodiesterace inhibitors DDIs
nitrates- severy hypotension
alpha blockers esp non selective agents
CYP3A4 substrates
which of the FQ is mostly renally cleared
levofloxacin
which of the FQ is mostly hepatically cleared?
moxifloxacin
DDIs of FQ
Polyvalent actions, MVs, bile acids, sucralfate : chelation leading to decreased absorption
They increase Warfarin, SUs and QT prolonging drugs
-NSAIDS and probenacid increase FQ levels
what is Rifampin a strong inducer of?
cyp 3A4
CYP 2C9
CYP 2c19
which of the statins undergo extensive first pass metabolism by cyp 3a4
simvastatin
lovastatin
atorvastatin (but more minimal)
max regimen of rosuvastatin on patients with ritonavir
10mg/day
max rosuvastati w/ cyclosporine?
5mg/day
DDI w/ tetracycliens
Diaveltn cations
can increase inr in warfarin
can decrease OC effectiness
avoid wi/ retinoic acid derrivatieves due to risk of pseudotumor cerebri
