Drug Interactions

Question 1

CYP INDUCERS (PS PORCS)

Answer 1

Phenytoin 
Smoking 
Phenobarbital 
Oxcarbazepine 
Rifampin 
Carbamazepine 
St. John's wort

Question 2

CYP INHIBITORS (G PACMAN)

Answer 2

Grapefruit juice 
Protease inhibitors 
Azoles 
Cyclosporine, cimetidine, cobicistat 
Macrolides (but NOT azithromycin) 
Amiodarone 
Non-DHP CCBs (diltiazem, verapamil)

Question 3

Effects of CYP inducers

Answer 3

• increased metabolism of substrates
• decreased serum concentrations and decreased clinical effect of substrates
• inDucers = Decreased levels/effects of substrates
• Prodrugs–inducers increase levels of active drug form

Question 4

Effects of CYP inhibitors

Answer 4

• decreased metabolism of substrates
• increased serum concentrations and increased clinical effects of substrates
• INhibitors = INcreased effects/levels/ADR/toxicities of substrates
• Prodrugs–inhibitors decrease levels of active drug form

Question 5

P-GP substrates
(PGP transports drugs and their metabolites out of the body by pumping them into the gut where they can be excreted in the stool)

Answer 5

• Anticoagulants- apixaban, rivaroxaban, edoxaban
• Cardiovascular drugs- carvediol, digoxin, ranolazine
• Immunosuppressants- cyclosporine, sirolimus, tacrolimus
• HCV drugs- dasabuvir, paritaprevir, simeprevir, sofosbuvir
• Others- colchicine, dolutegravir, raltegravir, saxagliptin

Question 6

P-GP inducers

Answer 6

carbamazepine 
dexamethasone 
phenobarbital
phenytoin 
rifampin 
St. John's wort 
tipranavir

Question 7

P-GP inhibitors

Answer 7

• Anti-infectives- clarithromycin, itraconazole, posaconazole
• Cardiovascular drugs- amiodarone, carvedilol, dronedarone, conivaptan, diltiazem, verapamil
• HIV drugs- cobicistat, ritonavir
• HCV drugs- daclatasvir, ledipasvir, simeprevir
• Others- cyclosporine, flibanserin, ticagrelor

Question 8

CYP3A4 substrates

Answer 8

• Analgesics- buprenorphine, diclofenac, fentanyl, hydrocodone, meloxicam, tramadol
• Anticoagulants
• Antidiabetic drugs- pioglitazone, repaglinide, saxagliptin, sitagliptin
• Antiplatelet drugs- cilostazol, prasugrel, ticagrelor
• Cardiovascular drugs- aminodarone, diltiazem, eplerenone, ivabradine, nifedipine, quinidine, tolvaptan, verapamil
• Immunosuppressants- cyclosporine, tacrolimus, sirolimus
• Statins- atorvastatin, lovastatin, simvastatin
• HIV drugs- atazanavir, efavirenz, ritonavir, tipramavir
• PDE-5 inhibitors- sildenafil, tadalafil, vardenafil

Question 9

CYP3A4 inducers

Answer 9

carbamazepine 
oxcarbazepine 
phenytoin
phenobarbital
primidone 
rifabutin 
rifampin 
rifapentine 
smoking 
St. John's wort

Question 10

CYP3A4 inhibitors

Answer 10

• Anti-infectives- clarithromycin, erythromycin, azoles, isoniazid
• Cardiovascular drugs- amiodarone, diltiazem, dronedarone, quinidine, ranolazine, verapamil
• HIV drugs- atazanavir, cobicistat, efavirenz, darunavir, ritonavir
• Others- aprepitant, cimetidine, cyclosporine, grapefruit juice, haloperidol, sertraline

Question 11

CYP1A2 substrates

Answer 11

alosetron, aprepitant, clozapine, cyclobenzaprine, duloxetine, ethinyl estradiol, fluvoxamine, methadone, mirtazapine, olanzapine, ondansetron, pimozide, propranolol, rasagiline, ropinirole, theophylline, warfarin

Question 12

CYP1A2 inducers

Answer 12

carbamazepine
phenobarbital
phenytoin
primidone 
rifampin 
ritonavir 
smoking**
St. John's wort

Question 13

CYP1A2 inhibitors

Answer 13

atazanavir 
cimetidine 
ciprofloxacin 
fluvoxamine 
zileuton

Question 14

CYP2C8 substrates

Answer 14

amiodarone 
dasabuvir 
pioglitazone 
repaglinide 
rosiglitazone

Question 15

CYP2C8 inducers

Answer 15

phenytoin

rifampin

Question 16

CYP2C8 inhibitors

Answer 16

amiodarone 
atazanaivr 
clopidogrel 
gemfibrozil 
ketoconazole 
bactrim 
ritonavir