KETOCONAZOLE

Ketoconazole, USP is a synthetic broad-spectrum antifungal agent. Each tablet, for oral administration, contains 200 mg ketoconazole, USP base. In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, corn starch, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and povidone. Ketoconazole is (±)cis-1-Acetyl-4-[p-[[2-(2,4-dichlorophenyl)-2-(imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-piperazine and has the following structural formula: C 26 H 28 Cl 2 N 4 O 4 M.W. 531.44 Ketoconazole, USP is a white or almost white powder that is soluble in acids. Structure

INDICATIONS & USAGE Ketoconazole tablets are not indicated for treatment of onychomycosis, cutaneous dermatophyte infections, or Candida infections. Ketoconazole tablets should be used only when other effective antifungal therapy is not available or tolerated and the potential benefits are considered to outweigh the potential risks. Ketoconazole tablets are indicated for the treatment of the following systemic fungal infections in patients who have failed or who are intolerant to other therapies: blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, and paracoccidioidomycosis. Ketoconazole tablets should not be used for fungal meningitis because it penetrates poorly into the cerebrospinal fluid.

DOSAGE & ADMINISTRATION There should be laboratory as well as clinical documentation of infection prior to starting ketoconazole therapy. The usual duration of therapy for systemic infection is 6 months. Treatment should be continued until active fungal infection has subsided. Adults The recommended starting dose of ketoconazole tablets is a single daily administration of 200 mg (one tablet). If clinical responsiveness is insufficient within the expected time, the dose of ketoconazole tablets may be increased to 400 mg (two tablets) once daily. Children In small numbers of children over 2 years of age, a single daily dose of 3.3 to 6.6 mg/kg has been used. Ketoconazole tablets have not been studied in children under 2 years of age.

Drug Interactions Coadministration of a number of CYP3A4 substrates such as dofetilide, quinidine cisapride and pimozide is contraindicated with ketoconazole tablets. Coadministration with ketoconazole can cause elevated plasma concentrations of these drugs and may increase or prolong both therapeutic and adverse effects to such an extent that a potentially serious adverse reaction may occur. For example, increased plasma concentrations of some of these drugs can lead to QT prolongation and sometimes resulting in life-threatening ventricular tachyarrhythmias including occurrences of torsade de pointes, a potentially fatal arrhythmia. Coadministration of ketoconazole tablets with lurasidone is contraindicated since it may result in an increase in lurasidone exposure and the potential for serious adverse reactions. (see PRECAUTIONS: Drug Interactions ). Additionally, the following other drugs are contraindicated with ketoconazole tablets: methadone, disopyramide, dronedarone, ergot alkaloids such as dihydroergotamine, ergometrine, ergotamine, methylergometrine, irinotecan, lurasidone, oral midazolam, alprazolam, triazolam, felodipine, nisoldipine, ranolazine, tolvaptan, eplerenone, lovastatin, simvastatin and colchicine (see PRECAUTIONS: Drug Interactions ). Enhanced Sedation Coadministration of ketoconazole tablets with oral midazolam, oral triazolam or alprazolam has resulted in elevated plasma concentrations of these drugs. This may potentiate and prolong hypnotic and sedative effects, especially with repeated dosing or chronic administration of these agents. Concomitant administration of ketoconazole tablets with oral triazolam, oral midazolam or alprazolam is contraindicated (see PRECAUTIONS: Drug Interactions ). Myopathy Coadministration of CYP3A4 metabolized HMG-CoA reductase inhibitors such as simvastatin, and lovastatin is contraindicated with ketoconazole tablets (see PRECAUTIONS: Drug Interactions ). Ergotism Concomitant administration of ergot alkaloids such as dihydroergotamine and ergotamine with ketoconazole tablets is contraindicated (see PRECAUTIONS: Drug Interactions ). Liver Disease The use of ketoconazole tablets are contraindicated in patients with acute or chronic liver disease. Hypersensitivity Ketoconazole tablets are contraindicated in patients who have shown hypersensitivity to the drug.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following adverse reactions were reported in clinical trials: Immune System Disorders: anaphylactoid reaction Endocrine Disorders: gynecomastia Metabolism and Nutrition Disorders: alcohol intolerance, anorexia, hyperlipidemia, increased appetite Psychiatric Disorders: insomnia, nervousness Nervous System Disorders: headache, dizziness, paresthesia, somnolence Eye Disorders: photophobia Vascular Disorders: orthostatic hypotension Respiratory, Thoracic and Mediastinal Disorders: epistaxis Gastrointestinal Disorders: vomiting, diarrhea, nausea, constipation, abdominal pain, abdominal pain upper, dry mouth, dysgeusia, dyspepsia, flatulence, tongue discoloration Hepatobiliary Disorders: hepatitis, jaundice, hepatic function abnormal Skin and Subcutaneous Tissues Disorders: erythema multiforme, rash, dermatitis, erythema, urticaria, pruritus, alopecia, xeroderma Musculoskeletal and Connective Tissue Disorders: myalgia Reproductive System and Breast Disorders: menstrual disorder General Disorders and Administration Site Conditions: asthenia, fatigue, hot flush, malaise, edema peripheral, pyrexia, chills Investigations: platelet count decreased. Postmarketing Experience The following adverse reactions have been identified during postapproval use of ketoconazole tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following adverse reactions were reported during postmarketing experience: Blood and Lymphatic System Disorders: thrombocytopenia Immune System Disorders: allergic conditions including anaphylactic shock, anaphylactic reaction, angioneurotic edema Endocrine Disorders: adrenocortical insufficiency Nervous System Disorders: reversible intracranial pressure increased (e.g., papilloedema, fontanelle bulging in infants) Hepatobiliary Disorders: serious hepatotoxicity including hepatitis cholestatic, biopsy-confirmed hepatic necrosis, cirrhosis, hepatic failure including cases resulting in transplantation or death Skin and Subcutaneous Tissue Disorders: acute generalized exanthematous pustulosis, photosensitivity Musculoskeletal and Connective Tissue Disorders: arthralgia Reproductive System and Breast Disorders: erectile dysfunction; with doses higher than the recommended therapeutic dose of 200 or 400 mg daily, azoospermia.

Ketoconazole is mainly metabolized through CYP3A4. Other substances that either share this metabolic pathway or modify CYP3A4 activity may influence the pharmacokinetics of ketoconazole. Similarly, ketoconazole may modify the pharmacokinetics of other substances that share this metabolic pathway. Ketoconazole is a potent CYP3A4 inhibitor and a P-glycoprotein inhibitor. When using concomitant medication, the corresponding label should be consulted for information on the route of metabolism and the possible need to adjust dosages. Interaction studies have only been performed in adults. The relevance of the results from these studies in pediatric patients is unknown. Drugs that may decrease ketoconazole plasma concentrations Drugs that reduce the gastric acidity (e.g., acid neutralizing medicines such as aluminum hydroxide, or acid secretion suppressors such as H 2 -receptor antagonists and proton pump inhibitors) impair the absorption of ketoconazole from ketoconazole tablets. These drugs should be used with caution when coadministered with ketoconazole tablets: Ketoconazole tablets should be administered with an acidic beverage (such as non-diet cola) upon co-treatment with drugs reducing gastric acidity. Acid neutralizing medicines (e.g., aluminum hydroxide) should be administered at least 1 hour before or 2 hours after the intake of ketoconazole tablets. Upon coadministration, the antifungal activity should be monitored and the ketoconazole tablets dose increased as deemed necessary. Coadministration of ketoconazole tablets with potent enzyme inducers of CYP3A4 may decrease the bioavailability of ketoconazole to such an extent that efficacy may be reduced. Examples include: Antibacterials: isoniazid, rifabutin (see also under 'Drugs that may have their plasma concentrations increased'), rifampicin. Anticonvulsants: carbamazepine (see also under 'Drugs that may have their plasma concentrations increased'), phenytoin. Antivirals: efavirenz, nevirapine. Therefore, administration of potent enzyme inducers of CYP3A4 with ketoconazole tablets is not recommended. The use of these drugs should be avoided from 2 weeks before and during treatment with ketoconazole tablets, unless the benefits outweigh the risk of potentially reduced ketoconazole efficacy. Upon coadministration, the antifungal activity should be monitored and the ketoconazole tablets dose increased as deemed necessary. 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. These drugs should be used with caution when coadministered with ketoconazole tablets. Patients who must take ketoconazole tablets concomitantly with potent inhibitors of CYP3A4 should be monitored closely for signs or symptoms of increased or prolonged pharmacologic effects of ketoconazole, and the ketoconazole tablets dose should be decreased as deemed necessary. When appropriate, ketoconazole plasma concentrations should be measured. Drugs that may have their plasma concentrations increased by ketoconazole Ketoconazole can inhibit the metabolism of drugs metabolized by CYP3A4 and can inhibit the drug transport by P-glycoprotein, which may result in increased plasma concentrations of these drugs and/or their active metabolite(s) when they are administered with ketoconazole. These elevated plasma concentrations may increase or prolong both therapeutic and adverse effects of these drugs. CYP3A4- metabolized drugs known to prolong the QT interval may be contraindicated with ketoconazole tablets, since the combination may lead to ventricular tachyarrhythmias, including occurrences of torsade de pointes, a potentially fatal arrhythmia. Examples of drugs that may have their plasma concentrations increased by ketoconazole presented by drug class with advice regarding coadministration with ketoconazole tablets: Drug Class Contraindicated Not Recommended Use with Caution Comments Under no circumstances should the drug be coadministered with ketoconazole tablets, and up to one week after discontinuation of treatment with ketoconazole. The use of the drug should be avoided during and up to one week after discontinuation of treatment with ketoconazole tablets, unless the benefits outweigh the potentially increased risks of side effects. If coadministration cannot be avoided, clinical monitoring for signs or symptoms of increased or prolonged effects or side effects of the interacting drug is recommended, and its dosage should be reduced or interrupted as deemed necessary. When appropriate, plasma concentrations should be measured. The label of the coadministered drug should be consulted for information on dose adjustment and adverse effects. Careful monitoring is recommended when the drug is coadministered with ketoconazole tablets. Upon coadministration, patients should be monitored closely for signs or symptoms of increased or prolonged effects or side effects of the interacting drug, and its dosage should be reduced as deemed necessary. When appropriate, plasma concentrations should be measured. The label of the coadministered drug should be consulted for information on dose adjustment and adverse effects Alpha Blockers tamsulosin Analgesics methadone alfentanil, buprenorphine IV and sublingual, fentanyl, oxycodone, sufentanil Methadone: The potential increase in plasma concentrations of methadone when coadministered with ketoconazole tablets may increase the risk of serious cardiovascular events including QT prolongation and torsade de pointes, or respiratory or CNS depression [See CONTRAINDICATIONS .] Fentanyl: The potential increase in plasma concentrations of fentanyl when coadministered with ketoconazole tablets may increase the risk of potentially fatal respiratory depression. Sufentanil: No human pharmacokinetic data of an interaction with ketoconazole are available. In vitro data suggest that sufentanil is metabolized by CYP3A4 and so potentially increased sufentanil plasma concentrations would be expected when coadministered with ketoconazole tablets. Antiarrhythmics disopyramide, dofetilide, dronedarone, quinidine digoxin Disopyramide, dofetilide, dronedarone, quinidine: The potential increase in plasma concentrations of these drugs when coadministered with ketoconazole may increase the risk of serious cardiovascular events including QT prolongation. Digoxin: Rare cases of elevated plasma concentrations of digoxin have been reported. It is not clear whether this was due to the combination of therapy. It is, therefore, advisable to monitor digoxin concentrations in patients receiving ketoconazole. Antibacterials rifabutin telithromycin Rifabutin: see also under 'Drugs that may decrease ketoconazole plasma concentrations' Telithromycin: A multiple-dose interaction study with ketoconazole showed that C max of telithromycin was increased by 51% and AUC by 95% Anticoagulants and Antiplatelet Drugs rivaroxaban cilostazol, coumarins, dabigatran Cilostazol: Concomitant administration of single doses of cilostazol 100 mg and ketoconazole 400 mg approximately doubled cilostazol concentrations and altered (increase/decrease) the concentrations of the active metabolites of cilostazol. Coumarins: Ketoconazole may enhance the anticoagulant effect of coumarin-like drugs; thus, the anticoagulant effect should be carefully titrated and monitored. Dabigatran: In patients with moderate renal impairment (CrCL 50 mL/min to ≤ 80 mL/min), consider reducing the dose of dabigatran to 75 mg twice daily when it is coadministered with ketoconazole. Anticonvulsants carbamazepine Carbamazepine: In vivo studies have demonstrated an increase in plasma carbamazepine concentrations in subjects concomitantly receiving ketoconazole. In addition, the bioavailability of ketoconazole may be reduced by carbamazepine Antidiabetics repaglinide, saxagliptin Antihelmintics and Antiprotozoals praziquantel Antimigraine Drugs ergot alkaloids, such as dihydroergotamine, ergometrine (ergonovine), ergotamine, methylergometrine (methylergonovine) eletriptan Ergot alkaloids: The potential increase in plasma concentrations of ergot alkaloids when coadministered with ketoconazole tablets may increase the risk of ergotism, i.e., a risk for vasospasm potentially leading to cerebral ischemia and/or ischemia of the extremities. Eletriptan: Eletriptan should be used with caution with ketoconazole, and specifically, should not be used within at least 72 hours of treatment with ketoconazole Antineoplastics irinotecan dasatinib, lapatinib, nilotinib bortezomib, busulphan, docetaxel, erlotinib, imatinib, ixabepilone, paclitaxel, trimetrexate, vinca alkaloids Irinotecan: The potential increase in plasma concentrations of irinotecan when coadministered with ketoconazole tablets may increase the risk of potentially fatal adverse events. Docetaxel: In the presence of ketoconazole, the clearance of docetaxel in cancer patients was shown to decrease by 50%. Antipsychotics, Anxiolytics and Hypnotics Lurasidone, alprazolam, oral midazolam, pimozide, triazolam aripiprazole, buspirone, haloperidol, midazolam IV, quetiapine, ramelteon, risperidone The increase in plasma concentrations of lurasidone when coadministered with ketoconazole tablets may increase the risk of serious side effects (See CONTRAINDICATIONS ). Alprazolam, midazolam, triazolam: Coadministration of ketoconazole tablets with oral midazolam or triazolam, or alprazolam may cause several-fold increases in plasma concentrations of these drugs. This may potentiate and prolong hypnotic and sedative effects, especially with repeated dosing or chronic administration of these agents. Pimozide: The potential increase in plasma concentrations of pimozide when coadministered with ketoconazole tablets may increase the risk of serious cardiovascular events including QT prolongation and torsade de pointes. Aripiprazole: Coadministration of ketoconazole (200 mg/day for 14 days) with a 15 mg single dose of aripiprazole increased the AUC of aripiprazole and its active metabolite by 63% and 77%, respectively. The effect of a higher ketoconazole dose (400 mg/day) has not been studied. When ketoconazole is given concomitantly with aripiprazole, them aripiprazole dose should be reduced to one-half of the recommended dose. Buspirone: Ketoconazole is expected to inhibit buspirone metabolism and increase plasma concentrations of buspirone. If a patient has been titrated to a stable dosage on buspirone, a dose reduction of buspirone may be necessary to avoid adverse events attributable to buspirone or diminished anxiolytic activity. Antivirals indinavir, maraviroc, saquinavir Beta Blockers nadolol Calcium Channel Blockers felodipine, nisoldipine other dihydropyridines, verapamil Calcium channel blockers can have a negative inotropic effect which may be additive to those of ketoconazole. The potential increase in plasma concentrations of calcium channel blockers when coadministered with ketoconazole tablets may increase the risk of edema and congestive heart failure. Dihydropyridines: Concomitant administration of ketoconazole tablets may cause several-fold increases in plasma concentrations of dihydropyridines Cardiovascular Drugs, Miscellaneous ranolazine aliskiren, bosentan Ranolazine: The potential increase in plasma concentrations of ranolazine when coadministered with ketoconazole tablets may increase the risk of serious cardiovascular events including QT prolongation. Bosentan: Coadministration of bosentan 125 mg twice daily and ketoconazole, increased the plasma concentrations of bosentan by approximately 2 fold in normal volunteers. No dose adjustment of bosentan is necessary, but patients should be monitored for increased pharmacologic effects and adverse reactions of bosentan. Diuretics eplerenone The potential increase in plasma concentrations of eplerenone when coadministered with ketoconazole tablets may increase the risk of hyperkalemia and hypotension. Gastrointestinal Drugs cisapride aprepitant Cisapride: Oral ketoconazole potently inhibits the metabolism of cisapride resulting in a mean eight-fold increase in AUC of cisapride, which can lead to serious cardiovascular events including QT prolongation. Immunosuppressants everolimus, rapamycin (also known as sirolimus), temsirolimus budesonide, ciclesonide, cyclosporine, dexamethasone, fluticasone, methylprednisolone, tacrolimus Rapamycin (sirolimus): Ketoconazole tablets 200 mg daily for 10 days increased the C max and AUC of a single 5 mg dose of sirolimus by 4.3 fold and 10.9 fold, respectively in 23 healthy subjects. Fluticasone: Coadministration of fluticasone propionate and ketoconazole is not recommended unless the potential benefit to the patient outweighs the risk of systemic corticosteroid side effects. Lipid Regulating Drugs lovastatin, simvastatin atorvastatin The potential increase in plasma concentrations of atorvastatin, lovastatin and simvastatin when coadministered with ketoconazole tablets may increase the risk of skeletal Muscle toxicity, including rhabdomyolysis. Respiratory Drugs salmeterol Urological Drugs fesoterodine, sildenafil, solifenacin, tadalafil, tolterodine, vardenafil Vardenafil: A single dose of 5 mg of vardenafil should not be exceeded when coadministered with ketoconazole. Other colchicine, in subjects with renal or hepatic impairment; tolvaptan colchicine alcohol, cinacalcet Colchicine: The potential increase in plasma concentrations of colchicine when coadministered with ketoconazole tablets may increase the risk of potentially fatal adverse events Tolvaptan: Ketoconazole 200 mg administered with tolvaptan increased tolvaptan exposure by 5 fold. Larger doses would be expected to produce larger increases in tolvaptan exposure. There is not adequate experience to define the dose adjustment that would be needed to allow safe use of tolvaptan with strong CYP3A inhibitors such as ketoconazole. Alcohol: Exceptional cases have been reported of a disulfiram-like reaction to alcohol, characterized by flushing, rash, peripheral edema, nausea and headache. All symptoms completely resolved within a few hours.