30 interactions on record
Use of colchicine in conjunction with P-gp or strong CYP3A4 inhibitors (this includes all protease inhibitors except fosamprenavir) is contraindicated in patients with renal or hepatic impairment [see Contraindications ( 4 )].
Source: FDA drug label - colchicine
Interaction Drug Interaction Rifabutin, phenytoin, efavirenz, cimetidine, esomeprazole* Avoid coadministration unless the benefit outweighs the risks ( 7.6 , 7.7 , 7.8 , 7.9 ) Other drugs metabolized by CYP3A4 Consider dosage adjustment and monitor for adverse effects and toxicity ( 7.1 , 7.10 , 7.11 ) Digoxin Monitor digoxin plasma concentrations ( 7.12 ) Fosamprenavir, metoclopramide* Monitor for breakthrough fungal infections ( 7.6 , 7.13 ) *The drug interactions with esomeprazole and metoclopramide do not apply to posaconazole tablets. Fosamprenavir: Combining fosamprenavir with posaconazole may lead to decreased posaconazole plasma concentrations.
Source: FDA drug label - posaconazole
Tipranavir Fosamprenavir Administered with rifampin 300 mg daily Decrease AUC by 82% Saquinavir Decrease AUC by 70% Coadministration may result in severe hepatocellular toxicity.
Source: FDA drug label - rifampin
Drugs That Affect Phenytoin Concentrations Interacting Agent Examples Drugs that may increase phenytoin serum levels Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole-trimethoprim Other Acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, disulfiram, estrogen, fluvastatin, isoniazid, methylphenidate, phenothiazines, salicylates, ticlopidine, tolbutamide, trazodone, warfarin Drugs that may decrease phenytoin serum levels Antineoplastic agents usually in combination Bleomycin, carboplatin, cisplatin, doxorubicin, methotrexate Antiviral agents Fosamprenavir, nelfinavir, ritonavir Antiepileptic drugs Carbamazepine, vigabatrin Other Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. Carbamazepine, felbamate, lamotrigine, topiramate, oxcarbazepine, lacosamide Antiplatelets Ticagrelor Antilipidemic agents Atorvastatin, fluvastatin, simvastatin Antiviral agents Efavirenz, lopinavir/ritonavir, indinavir, nelfinavir, ritonavir, saquinavir Fosamprenavir: phenytoin when given with fosamprenavir alone may decrease the concentration of amprenavir, the active metabolite. Phenytoin when given with the combination of fosamprenavir and ritonavir may increase the concentration of amprenavir Calcium channel blockers Nifedipine, nimodipine, nisoldipine, verapamil Other Albendazole (decreases active metabolite), chlorpropamide, clozapine, cyclosporine, digoxin, disopyramide, folic acid, methadone, mexiletine, praziquantel, quetiapine 7.3 Hyperammonemia with Concomitant Use of Valproate Concomitant administration of phenytoin and valproate has been associated with an increased risk of valproate-associated hyperammonemia.
Source: FDA drug label - fosphenytoin sodium
The recommended dose of BELSOMRA is 5 mg in subjects receiving moderate CYP3A inhibitors (e.g., amprenavir, aprepitant, atazanavir, ciprofloxacin, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, imatinib, verapamil).
Source: FDA drug label - suvorexant
In patients taking saquinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, fosamprenavir plus ritonavir, elbasvir plus grazoprevir or letermovir do not exceed atorvastatin 20 mg. Examples: Tipranavir plus ritonavir, glecaprevir plus pibrentasvir, lopinavir plus ritonavir, simeprevir, saquinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, fosamprenavir plus ritonavir, elbasvir plus grazoprevir, letermovir, nelfinavir, and ledipasvir plus sofosbuvir .
Source: FDA drug label - amlodipine and atorvastatin
In patients taking saquinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, fosamprenavir plus ritonavir, elbasvir plus grazoprevir or letermovir, do not exceed atorvastatin 20 mg. Examples: Tipranavir plus ritonavir, glecaprevir plus pibrentasvir, lopinavir plus ritonavir, simeprevir, saquinavir plus ritonavir, darunavir plus ritonavir, fosamprenavir, fosamprenavir plus ritonavir, elbasvir plus grazoprevir, letermovir, nelfinavir, and ledipasvir plus sofosbuvir.
Source: FDA drug label - atorvastatin calcium
This table includes potentially significant interactions, but is not all inclusive Table 5: Established and Other Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies or Predicted Interaction Concomitant Drug Class: Drug Name Effect Clinical Comment HIV antiviral agents Protease inhibitor: Fosamprenavir calcium ↓ amprenavir Fosamprenavir (unboosted): Appropriate doses of the combinations with respect to safety and efficacy have not been established. Fosamprenavir/ritonavir: An additional 100 mg/day (300 mg total) of ritonavir is recommended when efavirenz tablets are administered with fosamprenavir/ritonavir once daily. No change in the ritonavir dose is required when efavirenz tablets are administered with fosamprenavir plus ritonavir twice daily.
Source: FDA drug label - efavirenz
Protease inhibitor: fosamprenavir calcium ↓ amprenavir Fosamprenavir (unboosted): Appropriate doses of fosamprenavir and efavirenz, emtricitabine and tenofovir disoproxil fumarate with respect to safety and efficacy have not been established. Fosamprenavir/ritonavir: An additional 100 mg/day (300 mg total) of ritonavir is recommended when efavirenz, emtricitabine and tenofovir disoproxil fumarate is administered with fosamprenavir/ritonavir once daily. No change in the ritonavir dose is required when efavirenz, emtricitabine and tenofovir disoproxil fumarate is administered with fosamprenavir plus ritonavir twice daily.
Source: FDA drug label - efavirenz, emtricitabine and tenofovir disoproxil fumarate
HIV-antiviral agents: protease inhibitors (PIs) atazanavir (without ritonavir) atazanavir/ritonavir atazanavir/cobicistat darunavir/ritonavir darunavir/cobicistat fosamprenavir (without ritonavir) fosamprenavir/ritonavir indinavir (without ritonavir) lopinavir/ritonavir ↓ atazanavir ↓ atazanavir ↔ etravirine ↓ atazanavir ↓ cobicistat ↓ etravirine ↓ cobicistat darunavir: effect unknown ↑ amprenavir ↑ amprenavir ↓ indinavir ↓ etravirine Co-administration of etravirine tablets and atazanavir without low- dose ritonavir is not recommended. Concomitant use of etravirine tablets with fosamprenavir without low-dose ritonavir may cause a significant alteration in the plasma concentration of amprenavir. Co-administration of etravirine tablets and fosamprenavir without low-dose ritonavir is not recommended.
Source: FDA drug label - etravirine
Concomitant administration of famotidine with dasatinib, delavirdine mesylate, cefditoren, and fosamprenavir is not recommended.
Source: FDA drug label - famotidine
7 DRUG INTERACTIONS Coadministration of fosamprenavir calcium with drugs that induce CYP3A4 may decrease amprenavir (active metabolite) concentrations leading to potential loss of virologic activity. (7, 12.3) Coadministration of fosamprenavir calcium or fosamprenavir calcium and ritonavir may result in clinically significant interactions with drugs metabolized by CYP3A4. (7) Coadministration of fosamprenavir calcium and ritonavir may result in clinically significant interactions with drugs metabolized by CYP2D6.
Source: FDA drug label - fosamprenavir calcium
Intervention Concomitant administration of ibuprofen and famotidine tablet is not recommended with dasatinib, delavirdine mesylate, cefditoren, and fosamprenavir.
Source: FDA drug label - ibuprofen and famotidine
Drugs that may increase ketoconazole plasma concentrations Potent inhibitors of CYP3A4 (e.g., antivirals such as ritonavir, ritonavir-boosted darunavir and ritonavir-boosted fosamprenavir) may increase the bioavailability of ketoconazole.
Source: FDA drug label - ketoconazole
Examples Antivirals (e.g., ritonavir, ritonavir-boosted darunavir, ritonavir-boosted fosamprenavir, saquinavir) Glucocorticoid and progesterone receptor antagonists (e.g., mifepristone) Strong CYP3A4 Inducers Clinical Impact May decrease plasma concentrations of levoketoconazole and reduce the efficacy of RECORLEV Prevention or Management Administration of strong enzyme inducers of CYP3A4 with RECORLEV is not recommended.
Source: FDA drug label - levoketoconazole
Established and Other Potentially Significant Drug Interactions Concomitant Drug Class: Drug Name Effect on Concentration of Lopinavir or Concomitant Drug Clinical Comments HIV-1 Antiviral Agents HIV-1 Protease Inhibitor: fosamprenavir/ritonavir ↓ amprenavir ↓ lopinavir An increased rate of adverse reactions has been observed with co-administration of these medications.
Source: FDA drug label - lopinavir and ritonavir
Fosamprenavir* ↓ Amprenavir ↑ Nevirapine Co-administration of nevirapine and fosamprenavir without ritonavir is not recommended. Fosamprenavir/Ritonavir* ↓ Amprenavir ↑ Nevirapine No dosing adjustments are required when nevirapine is co-administered with 700/100 mg of fosamprenavir/ritonavir twice daily. The combination of nevirapine administered with fosamprenavir/ritonavir once daily has not been studied.
Source: FDA drug label - nevirapine
Antiviral Drugs Amprenavir, atanazavir, delavirine, fosamprinavir, indinavir, nelfinavir and ritonavir , as CYP3A inhibitors, can inhibit the metabolism of nifedipine and increase the exposure to nifedipine.
Source: FDA drug label - nifedipine
Fosamprenavir/Ritonavir Clinical Impact Co-administration of fosamprenavir/ritonavir with paroxetine significantly decreased plasma levels of paroxetine.
Source: FDA drug label - paroxetine
Fosamprenavir/Ritonavir Clinical Impact Co-administration of fosamprenavir/ritonavir with paroxetine significantly decreased plasma levels of paroxetine.
Source: FDA drug label - paroxetine hydrochloride
Fosamprenavir/Ritonavir Co-administration of fosamprenavir/ritonavir with paroxetine significantly decreased plasma levels of paroxetine.
Source: FDA drug label - paroxetine hydrochloride hemihydrate
Calcium carbonate, aluminum hydroxide, magnesium hydroxide Prevention or Management: Phenytoin and antacids should not be taken at the same time of day Antineoplastic agents (usually in combination) Bleomycin, carboplatin, cisplatin, doxorubicin, methotrexate Antiviral agents Fosamprenavir, nelfinavir, ritonavir Antiepileptic drugs Carbamazepine, vigabatrin Other Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. Warfarin Increased and decreased PT/INR responses have been reported when phenytoin is coadministered with warfarin Other Corticosteroids, doxycycline, estrogens, furosemide, oral contraceptives, paroxetine, quinidine, rifampin, sertraline, theophylline, and vitamin D Drugs whose level is decreased by phenytoin Antiepileptic drugs The effect of phenytoin on phenobarbital, valproic acid and sodium valproate serum levels is unpredictable Carbamazepine, felbamate, lamotrigine, topiramate, oxcarbazepine Antilipidemic agents Atorvastatin, fluvastatin, simvastatin Antiviral agents Efavirenz, lopinavir/ritonavir, indinavir, nelfinavir, ritonavir, saquinavir Fosamprenavir: phenytoin when given with fosamprenavir alone may decrease the concentration of amprenavir, the active metabolite. Phenytoin when given with the combination of fosamprenavir and ritonavir may increase the concentration of amprenavir Calcium channel blockers Nifedipine, nimodipine, nisoldipine, verapamil Other Albendazole (decreases active metabolite), chlorpropamide, clozapine, cyclosporine, digoxin, disopyramide, folic acid, methadone, mexiletine, praziquantel, quetiapine 7.3 Drug Enteral Feeding/Nutritional Preparations Interaction Literature reports suggest that patients who have received enteral feeding preparations and/or related nutritional supplements have lower than expected phenytoin serum levels.
Source: FDA drug label - phenytoin
Table 1: Drugs That Affect Phenytoin Concentrations Interacting Agent Examples Drugs that may increase phenytoin serum levels Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole trimethoprim Other Acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, disulfiram, estrogen, fluvastatin, isoniazid, methylphenidate, phenothiazines, salicylates, ticlopidine, tolbutamide, trazodone, warfarin Drugs that may decrease phenytoin serum levels Antineoplastic agents usually in combination Bleomycin, carboplatin, cisplatin, doxorubicin, methotrexate Antiviral agents Fosamprenavir, nelfinavir, ritonavir Antiepileptic drugs Carbamazepine, vigabatrin Other Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. Warfarin Increased and decreased PT/INR responses have been reported when phenytoin is coadministered with warfarin Other Corticosteroids, doxycycline, estrogens, furosemide, oral contraceptives, paroxetine, quinidine, rifampin, sertraline, theophylline, and vitamin D Drugs whose level is decreased by phenytoin Antiepileptic drugs a Carbamazepine, felbamate, lamotrigine, topiramate, oxcarbazepine Antilipidemic agents Atorvastatin, fluvastatin, simvastatin Antiviral agents Efavirenz, lopinavir/ritonavir, indinavir, nelfinavir, ritonavir, saquinavir Fosamprenavir: phenytoin when given with fosamprenavir alone may decrease the concentration of amprenavir, the active metabolite. Phenytoin when given with the combination of fosamprenavir and ritonavir may increase the concentration of amprenavir Calcium channel blockers Nifedipine, nimodipine, nisoldipine, verapamil Other Albendazole (decreases active metabolite), chlorpropamide, clozapine, cyclosporine, digoxin, disopyramide, folic acid, methadone, mexiletine, praziquantel, quetiapine a The effect of phenytoin on phenobarbital, valproic acid and sodium valproate serum levels is unpredictable 7.3 Drug/Laboratory Test Interactions Care should be taken when using immunoanalytical methods to measure serum phenytoin concentrations following fosphenytoin administration.
Source: FDA drug label - phenytoin sodium
Other boosted PIs (atazanavir/ritonavir, fosamprenavir/ritonavir, saquinavir/ritonavir, tipranavir/ritonavir) ↑ rilpivirine ↔ boosted PI Concomitant use of EDURANT or EDURANT PED with boosted PIs may cause an increase in the plasma concentrations of rilpivirine (inhibition of CYP3A enzymes). Unboosted PIs (atazanavir, fosamprenavir, indinavir, nelfinavir) ↑ rilpivirine ↔ unboosted PI Concomitant use of EDURANT or EDURANT PED with unboosted PIs may cause an increase in the plasma concentrations of rilpivirine (inhibition of CYP3A enzymes).
Source: FDA drug label - rilpivirine hydrochloride
7 DRUG INTERACTIONS When co-administering ritonavir with other protease inhibitors (atazanavir, darunavir, fosamprenavir, saquinavir, and tipranavir), see the full prescribing information for that protease inhibitor including important information for drug interactions. Established and Other Potentially Significant Drug Interactions Concomitant Drug Class: Drug Name Effect on Concentration of Ritonavir or Concomitant Drug Clinical Comment HIV-Antiviral Agents HIV-1 Protease Inhibitor: atazanavir darunavir fosamprenavir ↑ amprenavir ↑ atazanavir ↑ darunavir See the complete prescribing information for fosamprenavir, atazanavir, darunavir for details on co-administration with ritonavir.
Source: FDA drug label - ritonavir
The combinations of fosamprenavir/ritonavir or tipranavir/ritonavir, which are anti-HIV-1 drugs, produce little or no change in rosuvastatin exposure.
Source: FDA drug label - rosuvastatin
The combinations of fosamprenavir/ritonavir or tipranavir/ritonavir, which are anti-HIV-1 drugs, produce little or no change in rosuvastatin exposure.
Source: FDA drug label - rosuvastatin calcium
Protease Inhibitors (co-administered with 200 mg of ritonavir): Fosamprenavir ↓ Amprenavir Combining a protease inhibitor with APTIVUS/ritonavir is not recommended.
Source: FDA drug label - tipranavir
Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.
Source: FDA drug label - warfarin
Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3 .
Source: FDA drug label - warfarin sodium