CYP3A4 inhibitor

Ekins S, Bravi G, Binkley S, Gillespie JS, Ring BJ, Wikel JH, et al. Three and four dimensional-quantitative structure activity relationship analyses of CYP3A4 inhibitors. J Pharmacol Exp Ther 1999 290 429-38. 

Theoretically buprenorphine metabolism could be inhibited by itraconazole, ketoconazole, grapefruit juice, and erythromycin or any other CYP3A4 inhibitor the effects may be greater than expected for the dose of buprenorphine being given may need to decrease buprenorphine dose. 

Darunavir (DRV) 300 mg tablet DRV 600 mg + Use with caution in Should be given Skin rash (has a sulfonamide CYP3A4 inhibitor and... 

Fosamprenavir (fAPV) Lexiva 700-mg tabs ARV-na ive pts fAPV 1,400 mg bid or fAPV 700 mg + RTV 1 00 mg bid PS-experienced pts fAPV 700 mg + RTV 1 00 mg bid Co-admin is tra tion w/EFV fAPV 700 mg + RTV 1 00 mg bid or fAPV 1400 mg + RTV 300 mg qday Child-Pugh Dose Class 5-8 700 mg bid 9-12 Not recommended Ritonavir should not be used in patients with hepatic impairment None Skin rash diarrhea, nausea and vomiting headache hyperlipidemia LFT elevation hyperglycemia fat maldistribution increased bleeding episodes in patients with hemophilia CYP3A4 inhibitor, inducer, and substrate... 

Indinavir (IDV) 200-, 333-, 800 mg q8hours Mild to moderate hepatic For unboosted IDV Nephrolithiasis Gl intolerance, CYP3A4 inhibitor... 

Lopinavir + ritonavir LPV 200 mg + 2 tablets or 5 ml Use with caution in patients Take with food (AUC Nausea, vomiting, diarrhea CYP3A4 inhibitor... 

Use of a hERG blocker in a patient also taking CYP3A4 inhibitors (e.g. antibacterial macrolides, azole antifungals, HIV protease inhibitors) or CYP2D6 inhibitors (quinidine, halofantrine, fluoxetine, paroxetine, thioridazine, terbinafine) the hERG blocker, if mostly metabolized by these CYP isoforms, may accumulate because... 

Pornpakakul S et ai, Diaporthichalasin, a novel CYP3A4 inhibitor from an... 

CYP3A4 inhibitors If concomitant administration with ketoconazole or any other CYP3A4 inhibitor is indicated, closely monitor patients for increased signs and/or symptoms of hypercorticism. Consider reduction in budesonide dose. 

Hypersensitivity to quinazolines (eg, doxazosin, prazosin, terazosin) moderate or severe hepatic insufficiency coadministration with potent CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir). 

For patients receiving weak CYP3A4 inhibitors (eg, erythromycin, saquinavir, verapamil, fluconazole), reduce the starting dose to 25 mg once daily. 

Metabolism - Epierenone is primarily metabolized via CYP3A4. Inhibitors of CYP3A4 increase blood levels of epierenone. 

All patients with the following conditions Serum potassium greater than 5.5 mEq/L at initiation Ccr 30 mL/min or less concomitant use with the following potent CYP3A4 inhibitors Ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, and nelfinavir. 

Drugs that may affect epierenone include ACE inhibitors, angiotensin II antagonists, CYP3A4 inhibitors, NSAIDs, and St. John s wort. Drugs that may be affected by epierenone include lithium. 

Drugs that may be affected by HMG-CoA reductase inhibitors include oral contraceptives, diclofenac, digoxin, glyburide, phenytoin, and warfarin. Atorvastatin, lovastatin, and simvastatin are primarily metabolized by CYP3A4 they may interact with CYP3A4 inhibitors. 

Concomitant mecf/caf/ons - The dosage of vardenafil may require adjustment in patients receiving certain CYP3A4 inhibitors. For ritonavir, do not exceed a single dose of 2.5 mg vardenafil in a 72-hour period. For indinavir, ketoconazole 400 mg/day, and itraconazole 400 mg/day, do not exceed a single dose of 2.5 mg vardenafil in a 24-hour period. For ketoconazole 200 mg/day, itraconazole 200 mg/day, and erythromycin, do not exceed a single dose of 5 mg vardenafil in a 24-hour period. 

Drugs that may interact with darifenacin include moderate and potent CYP3A4 inhibitors, anticholinergic drugs, CYP2D6 substrates, and digoxin. 

Dose adjustment with CYP3A4 inhibitors When administered with therapeutic doses of ketoconazole or other potent CYP3A4 inhibitors, a daily dose greater than 5 mg is not recommended. 

CYP3A4 inhibitors In vitro studies have shown that eletriptan is metabolized by the... 

Pregnancy (ergotamine s powerful uterine stimulant actions may cause fetal harm) hypersensitivity to ergot alkaloids peripheral vascular disease (eg, thromboangiitis obliterans, leutic arteritis, severe arteriosclerosis, thrombophlebitis, Raynaud s disease) hepatic or renal impairment severe pruritus coronary artery disease hypertension sepsis. The use of potent CYP3A4 inhibitors (ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is contraindicated. 

CYP3A4 inhibitors (eg, macrolide antibiotics, protease inhibitors) There have been rare reports of serious adverse events in connection with the coadministration. Fibrotic complications There have been reports of pleural and retroperitoneal fibrosis in patients following prolonged daily use of injectable dihydroergotamine. Risk of myocardial Ischemia and/or Ml and other adverse cardiac events Do not use dihydroergotamine in patients with documented ischemic or vasospastic coronary artery disease. 

Aprepitant is a moderate CYP3A4 inhibitor. Aprepitant should not be used concurrently with pimozide or cisapride. Inhibition of cytochrome P450 isoenzyme 3A4 (CYP3A4) by aprepitant could result in elevated plasma concentrations of these drugs, potentially causing serious or life-threatening reactions. Aprepitant is contraindicated in patients who are hypersensitive to any component of the product. 

Drugs that may interact with clozapine include caffeine, SSRIs, benzodiazepines, risperidone, CYP1A2 induces/inhibitors, CYP3A4 inhibitors, phenobarbital, and ritonavir. 

Concomitant use with potential CYP3A4 inhibitors - During coadministration of ketoconazole with aripiprazole, reduce the aripiprazole dose to one-half of the usual dose. 

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