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Medications to Know - Pertinent Drug Interactions Part 2

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teaherbalist2's version from 2016-07-17 18:05

Section

Question Answer
Glyburide1) Cimetidine may ↑ hypoglycemia effects (CYP mediated)
2) Chronical ethanol ingestion may ↓ hypoglycemic effect
Glipizide1) Cimetidine may ↑ hypoglycemia effects (CYP mediated)
2) Chronical ethanol ingestion may ↓ hypoglycemic effect
Glimepiride1) Cimetidine may ↑ hypoglycemia effects (CYP mediated)
2) Chronical ethanol ingestion may ↓ hypoglycemic effect
MetforminCimetidine ↑ peak metformin plasma and whole blood concentration by 60%.
PioglitazoneCYP3A4 and CYP2C8 inducers ↓ effect
Exenatide1) Delays gastric emptying and may ↓ absorption of concurrently administered drugs
2) Administer other meds 1 hour prior
SitagliptinMay ↑ digoxin levels
LevothyroxineDrugs that will ↓ absorption:
1) Cholestyramine
2) Aluminum containing agents
3) Sucralfate
4) Kayexalate
5) Phenytoin
6) Carbamazepine
7) Rifampin
MedroxyprogesteroneDrugs that will ↓ absorption:
1) Cholestyramine
2) Aluminum containing agents
3) Sucralfate
4) Kayexalate
5) Phenytoin
6) Carbamazepine
7) Rifampin
SpironolactoneMay reduce the inotropic effect of digoxin and mitotane
FinasterideCYP 3A4 substrate
CarbamazepineStrong CYP3A4 inducer
Valproic acid1) Carbamazepine: ↓ VPA, ↑ carbamazepine
2) Lamotrigine: ↑ toxicity of lamotrigine
3) Phenobarbital: ↓ VPA, ↑ phenobarbital
4) Primidone: ↓ VPA, ↑ primidone
5) Phenytoin: ↓ VPA, ↓ phenytoin
Phenytoin1) Strong CYP3A4 inducer
2) Reduce efficacy of oral contraceptives
OxcarbazepineCYP3A4 inducer
Lamotrigine1) Carbamazepine: ↓ lamotrigine
2) Phenobarbital: ↓ lamotrigine
3) Phenytoin: ↓ lamotrigine
4) Primidone: ↓ lamotrigine
5) VPA: ↑ lamotrigine
GabapentinSedative side effects: CNS depressants, alcohol, opioids
Topiramate1) Alcohol: ↑ CNS depressant effect
2) Carbamazepine: ↓ topiramate
3) Metformin: ↑ metformin adverse effects
4) Phenytoin: ↓ topiramate
5) Simeprevir: ↓ simeprevir
6) VPA: ↓ VPA
7) Oral contraceptives: ↓ contraceptives
Levetiracetam1) Calcifediol (theoretical)
2) Methotrexate (probable)
3) Orlistat (probable)
PhenobarbitalStrong CYP3A4 inhibitor
Zonisamide1) Carbamazepine: ↓ zonisamide
2) Phenytoin: ↓ zonisamide
3) Phenobarbital: ↓ zonisamide
Carbidopa/Levodopa1) Nonselective MAOIs should be avoided, may cause hypertensive crisis
2) Pyridoxine ↓ effectiveness of levodopa
Pramipexole1) ↓ levodopa dose by 20-30% when initiating
2) Metoclopramide and antipsychotics ↓ efficacy
Ropinirole1) ↓ levodopa dose by 20-30% when initiating
2) Metoclopramide and antipsychotics ↓ efficacy
BenztropineAdditive effects with other anticholinergics
TrihexyphenidylAdditive effects with other anticholinergics
Aspirin or APAP with butalbital and caffeine1) Alcohol
2) Additive CNS depression with butalbital
SumatriptanMAO-A inhibitors ↑ triptan levels and risk of serotonin syndrome and cardiac side effects
RizatriptanMAO-A inhibitors ↑ triptan levels and risk of serotonin syndrome and cardiac side effects
Donepezil1) Avoid succinylcholine due to prolonged neuromuscular blockade
2) Anticholinergics ↓ efficacy of donepezil
3) Ramelteon, ketoconazole, bethanechol, quinidine
Memantine1) Carbonic anhydrase inhibitors
2) Nicotine polacrilex
3) Quinidine
4) Ranitidine
5) Sodium bicarbonate
6) Cimetidine
7) Hydrochlorothiazide
Famotidine1) Less CYP inhibition compared to cimetidine
2) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
Ranitidine1) Less CYP inhibition compared to cimetidine
2) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
Dexlansoprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
Esomeprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
Lansoprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
Omeprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
Pantoprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
Rabeprazole1) May ↓ absorption of pH dependent drugs (e.g. itraconazole, ketoconazole, iron, atazanavir, mycophenolate mofetil)
2) May ↓ antiplatelet effects of clopidogrel
MetoclopramideUse with antipsychotics may ↑ risk of EPS
SucralfateMay bind to numerous drugs, separate by at least 2 hrs
Methotrexate1) NSAIDs and salicylates may ↑ risk of toxicity
2) Penicillins, sulfonamides, and tetracyclines may ↑ risk of toxicity
Calcium Acetate1) May ↓ concentration of phenytoin, ketoconazole, levothyroxine, tetracycline antibiotics, separate calcium acetate by 2 hrs before or 4 hrs after.
2) If taken with digoxin can cause an arrhythmia
Calcitriol1) Aluminum hydroxide: ↑ aluminum concentration
2) Bile acid sequestrants: ↓ serum concentration of vitamin D analogs
3) Sucralfate: vitamin D analogs ↑ concentration
Tamoxifen1) CYP3A4 substrate
2) May ↑ effects of warfarin
AnastrozoleNone significant
MethylprednisoloneCYP3A4 substrate
Ondansetron1) CYP3A4 substrate
2) Use with serotonergic agents may ↑ risk of serotonin syndrome
Citalopram1) Other serotonergic medications, such as MAOI, SSRI, triptans, linezolid, St. John's wort, tramadol, phenytoin
2) Concomitant use with 2C19 inhibitors; max dose = 20mg due risk of QT prolongation
Escitalopram1) Other serotonergic medications, such as MAOI, SSRI, triptans, linezolid, St. John's wort, tramadol, phenytoin
2) Concomitant use with 2C19 inhibitors; max dose = 20mg due risk of QT prolongation
Fluoxetine1) Other serotonergic medications, such as MAOI, SSRI, triptans, linezolid, St. John's wort, tramadol, phenytoin
2) Drugs metabolized by CYP P450
Paroxetine1) Other serotonergic medications, such as MAOI, SSRI, triptans, linezolid, St. John's wort, tramadol, phenytoin
2) Tamoxifen
SertralineOther serotonergic medications
AmitriptylineOther serotonergic medications
DoxepinOther serotonergic medications
ImipramineOther serotonergic medications
NortriptylineOther serotonergic medications
DuloxetineOther serotonergic medications
VenlafaxineOther serotonergic medications
Desvenlafaxine1) Other serotonergic medications, such as MAOI, SSRI, triptans, linezolid, St. John's wort, tramadol, phenytoin
2) ↑ risk of bleeding when used in combination with anticoagulants, thrombolytics
BupropionMAOIs
Mirtazapine1) MAOIs
2) Clonidine
3) Tramadol
4) Fluoxetine
5) Fluvoxamine
6) Linezolid
7) Olanzapine
8) Venlafaxine
Alprazolam1) Ketoconazole
2) Itraconazole
3) Alcohol
4) CNS depressants
5) Digoxin
6) Fluoxetine
7) Propoxyphene
8) Nefazodone
Clonazepam1) Alcohol
2) CNS depresants
3) Ketoconazole
Diazepam1) Alcohol
2) CNS depresants
3) Ketoconazole
Lorazepam1) Alcohol
2) CNS depresants
3) Ketoconazole
Buspirone1) MAOIs
2) Non-DHP CCBs
3) Inhibitors/inducers of CYP450
4) Macrolides
5) SSRIs
Hydroxyzine1) Antihistamines
2) MAOIs
3) CNS depressants
Lithium
Prochlorperazine1) Alcohol
2) CNS depressants
3) Lithium
4) Warfarin
5) Other phenothiazines
6) Propranolol
7) Pindolol
8) VPA
9) Phenytoin
10) Atropine
Haloperidol1) Alcohol
2) CNS depressants
3) Antiparkison medication
4) Lithium
5) Inhibitors/inducers of CYP450
Aripiprazole1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
Olanzapine1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
Paliperidone1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
Quetiapine1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
Risperidone1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
Ziprasidone1) Ranolazine
2) Carbamazepine
3) Quinidine
4) Ketoconazole
5) Medications that prolong QT
6) Metoclopramide
EszopicloneAvoid in combination with:
1) CNS depressants due to additive effects
2) Strong CYP3A4 inhibitors due to ↑ sedative serum concentration
ZolpidemAvoid in combination with:
1) CNS depressants due to additive effects
2) Strong CYP3A4 inhibitors due to ↑ sedative serum concentration
TemazepamAvoid in combination with CNS depressants due to additive effects
MethylphenidateMAOIs require 14 day washout peroid prior to stimulant initiation
Dextroamphetamine and Amphetamine IRMAOIs require 14 day washout peroid prior to stimulant initiation
LisdexamfetamineMAOIs require 14 day washout peroid prior to stimulant initiation
Atomoxetine1) Metabolized by CYP2D6: ↓ dose if on strong inhibitor (paroxetine, fluoxetine, quinidine)
2) MAOIs: 14 day washout required
Guanfacine1) Metabolized by CYP3A4: Limit daily dose to 2 mg if used in combination with 3A4 inhibitors
2) Additive CNS depressant effects with other depressants
3) Additive BP lowering effect with other antihypertensives
Clonidine1) Additive sedation with other CNS depressants
2) Additive BP lowering effect with other antihypertensives
Diclofenac1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Indomethacin1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Ibuprofen1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Naproxen1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Piroxicam1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Meloxicam1) Other salicylates
2) Warfarin
3) Lithium
4) ACEIs
Celecoxib1) Other salicylates (including aspirin)
2) Warfarin
3) Lithium
4) ACEIs
Hydrocodone/APAP1) Alcohol
2) Other CNS depressants
3) MAOIs
Codeine1) Alcohol
2) Other CNS depressants
3) MAOIs
Morphine1) Alcohol
2) Other CNS depressants
3) MAOIs
Oxycodone1) Alcohol
2) Other CNS depressants
3) MAOIs
Oxycodone/APAP1) Alcohol
2) Other CNS depressants
3) MAOIs
Fentanyl1) Alcohol
2) Other CNS depressants
3) MAOIs
4) CYP3A4 inducers and inhibitors
Hydromorphone1) Alcohol
2) Other CNS depressants
3) MAOIs
Methadone1) Alcohol
2) Other CNS depressants
3) MAOIs
4) Other QT prolonging drugs
Tramadol1) Alcohol
2) Opioids
3) SSRIs
4) MAOIs
5) Warfarin
PregabalinSedative effects additive with CNS depressants, alcohol, opiates
PrednisoneWarfarin
Hydroxychloroquine1) Cyclosporine
2) Digoxin
AlendronateNSAIDs/aspirin ↑ risk of symptoms
RisedronateNSAIDs/aspirin ↑ risk of symptoms
IbandronateNSAIDs/aspirin ↑ risk of symptoms
Raloxifene1) Cholestyramine
2) Warfarin
Allopurinol1) Mercaptopurine
2) Azathioprine
Timolol1) ↑ risk of systemic side effects with oral beta blockers
2) ↑ risk of bradycardia or heart block with digoxin, verapamil, diltiazem, ivabradine, or clonidine
BimatoprostNone significant
LatanoprostNone significant
TravoprostNone significant
Brimonidine↑ risk of systemic side effects with CNS depressants
Folic AcidMay ↓ serum levels of phenytoin
Ethinyl Estradiol/NorgestrelFollowing ↓ oral contraceptive pill efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
Use backup method during use and for 1 wk after; for chronic therapy use alternative form of contraception
Mestranol/Norethindrone↓ efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
Ethinyl Estradiol/Drospirenone↓ efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
Ethinyl Estradiol/Northinedrone↓ efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
Ethinyl Estradiol/Norgestimate↓ efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
Ethinyl Estradiol/Etonogestrel↓ efficacy:
1) Antibiotics (ampicillin, sulfonamides, tetracycline)
2) Anticonvulsants (phenytoin, topiramate, barbiturates)
3) Protease inhibitors
4) Rifampin
LevonorgestrelNone significant
Sildenafil1) Nitrates, avoid concomitant use within 24 hr
2) Alpha blockers: Potential significant ↓ in BP; avoid combination or use lowest dose of each agent with close monitoring
3) CYP3A4 substrate
Tadalafil1) Nitrates, avoid concomitant use within 48 hr
2) Alpha blockers: Potential significant ↓ in BP; avoid combination or use lowest dose of each agent with close monitoring
3) CYP3A4 substrate
Testosterone↑ effects of anticoagulants and cyclosporine
TamsulosinCimetidine ↑ levels
DutasterideCYP3A4 substrate
OxybutyninAdditive effects with other anticholinergics
TolterodineAdditive effects with other anticholinergics
Darifenacin1) CYP3A4 substrate
2) Additive effects with other anticholinergics
Solifenacin1) CYP3A4 substrate
2) Additive effects with other anticholinergics
Fesoterodine1) CYP3A4 substrate, doses above 4mg not recommend concomitantly
2) Additive effects with other anticholinergics
TrospiumAdditive effects with other anticholinergics
Tacrolimus1) Live vaccines
2) CYP3A4 substrates, inducers, inhibitors
3) K-sparing diuretics
4) Other immunosuppressants
VareniclineNicotine
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