Drug Metabolism Flashcards
CYP1A2 Substrates
TCAs (amitriptyline, clomipramine, desipramine, imipramine)
Duloxetine
Theophylline
CYP1A2 Inhibitors
Amiodarone
Ciprofloxacin*
Cimetidine
Estrogens (HRT and OC)
CYP1A2 Inducers
Carbamazepine/phenytoin
Rifampin
Smoking
THC
CYP2C8 or 9 Substrates
Carvedilol Phenytoin Pioglitazone TCAs (amitriptyline, clomipramine, desipramine, imipramine) Warfarin*
CYP2C8 or 9 Inhibitors
Amiodarone Gemfibrozil/fenofibrate Fluconazole Metronidazole TMP-SMX Clopidogrel Valproate
CYP2C8 or 9 Inducers
Carbamazepine/Phenytoin
Rifampin
St John’s Wort
CYP2C19 Substrates
Phenytoin Citalopram Clopidogrel Most PPIs* TCAs (normal 4)
CYP2C19 Inhibitors
Fluconazole Fluoxetine Cimetidine Gemfibrozil Omeprazole/esomeprazole
CYP2C19 Inducers
Carbamazepine/Phenytoin
Rifampin
St John’s Wort
CYP2D6 Substrates
Atypical antipsychotics (aripiprazole, risperidone) Codeine* SSRI (fluoxetine and paroxetine) SNRI (duloxetine) Metoprolol TCAs
CYP2D6 Inhibitors
Amiodarone
Antidepressants (fluoxetine, sertraline, paroxetine, duloxetine, bupropion)
Cimetidine
CYP2D6 Inducers
NONE*
CYP3A4 Substrates
DOACs (apixaban/rivaroxaban), Amiodarone, Atorvastatin/Simvastatin, BZDs, Carbamazepine, CCBs (amlodipine, verapamil, diltiazem), Clarithromycin,
Cyclosporine/tacrolimus/ sirolimus, Estrogens, Protease inhibitors, PDE5 inhibitors, OCPs, Opioids, SSRIs (citalopram, paroxetine, sertraline), Theophylline
CYP3A4 Inhibitors
Amiodarone Non-DHP CCBs (verapamil, diltiazem) Cimetidine Clarithromycin Fluconazole Grapefruit juice* Protease inhibitors
CYP3A4 Inducers
Carbamazepine/Phenytoin
Rifampin
St John’s Wort
Phase I Reactions
Polar groups are added to the lipophilic parent compounds by oxidation, reduction, or hydrolysis to facilitate water-solubility
Phase II Reactions
Glucuronic acid (glucuronidation)
Sulfate (sulfation)
Acetate (acetylation)
Methyl group (methylation)
Factors affecting Cytochrome P450
Enzyme Diet (grapefruit inhibits CYP3A, chronic ETOH increases CYP2E1 and decreases glutathione levels) Other drugs (especially with Narrow TI) Age Genetics Underlying liver disease
Drugs with Narrow Therapeutic Windows
Amiodarone DOACs Antipsychotics Carbamazepine Colchicine Transplant meds Statins Levothyroxine Oxycodone Maybe CCBs
Drugs and ETOH - Increase Sedation
ETOH + opioids, BZDs, NBRAs, TCAs, 1st gen antihistamines, antipsychotics, and muscle relaxants
Drugs and ETOH - Increase intoxication
ETOH + varenicline
Drugs and ETOH - Increase GI toxicity
ETOH (3 or more days) + NSAIDs, systemic steroids
Drugs and ETOH - Increase hepatotoxicity
ETOH (3 or more days) + INH, MTX, APAP
Drugs and ETOH - Disulfuram rxn
ETOH + metronidazole or tinidazole
Drugs and ETOH - Increase bleed risk
ETOH + anti-thrombotics (warfarin and DOACs)
Drugs and ETOH - Severe hypertension
ETOH + MAOIs
Drugs and ETOH - Severe hypotension
ETOH + alpha blockers, beta blockers, and CCBs
PGP Subtrates
Amiodarone Atorvastatin/Simvastatin Carbamazepine/Phenytoin Dabigatran/Rivaroxaban Digoxin Diltiazem Estrogen Omeprazole Paroxetine/Sertraline Many chemotherapeutics
PGP Inhibitors
Amiodarone
Carvedilol
Clarithromycin
Diltiazem/Verapamil
PGP Inducers
Carbamazepine/Phenytoin
Dexamethasone
Rifampin
St. John’s Wort