Methadone Ketoconazole

Drugs that may be affected by nevirapine include rifamycins, clarithromycin, oral contraceptives, efavirenz, ketoconazole, methadone, protease inhibitors, warfarin, zidovudine. 

St. John s wort, rifamycins, and ritonavir. Drugs that may be affected by efavirenz include phenytoin, phenobarbital, carbamazepine, itraconazole, ketoconazole, methadone, ritonavir, amprenavir, benzodiazepines, clarithromycin, ethinyl estradiol, indinavir, nelfinavir, saquinavir, and warfarin. 

Nevirapine NNRTI 200 mg bid Rash, hepatitis, nausea, headache Dose-escalate from 200 mg qd over 14 days to decrease frequency of rash. Avoid concurrent use with ketoconazole, methadone, and... 

Clinically important, potentially hazardous interactions with amiodarone, astemizole, bepridil, carbamazepine, chloroquine, cisapride, clarithromycin, dihydroergotamine, disopyramide, ergotamine, grapefruit juice, halofantrine, haloperidol, itraconazole, ketoconazole, methadone, moxifloxacin, phenobarbital, phenytoin, pimozide, procainamide, quinidine, rifampicin, ritonavir, sotalol, St John s wort, telithromycin, terfenadine, voriconazole... 

Toxicity and interactions Rifampin commonly causes light chain proteinuria and may impair antibody responses. Occasional side effects include skin rashes, thrombocytopenia, nephritis, and hver dysfunction. If given less often than twice weekly, rifampin may cause a flu-hke syndrome and anemia. Rifampin strongly induces liver dmg-metabolizing enzymes and enhances the elimination rate of many drugs including anticonvulsants, contraceptive steroids, cyclosporine, ketoconazole, methadone, and warfarin. 

Also analyzed astemizole, indinavir, ketoconazole, methadone, nelflnavir, rifabutin, rifampin, ritonavir, saquinavir, terfenadine, trimethoprim... 

The answer is b. (Katzungr pp 806—807J Rifampin induces cytochrome P450 enzymes, which causes a significant increase in elimination of drugs, such as oral contraceptives, anticoagulants, ketoconazole, cyclosporine, and chloramphenicol. It also promotes urinary excretion of methadone, which may precipitate withdrawal. 

Drugs that may be affected by fosamprenavir include the following Amiodarone, amitriptyline, benzodiazepines, calcium channel blockers, cisapride, contraceptives (oral), cyclosporine, ergot derivatives, HMG-CoA reductase inhibitors, imipramine, itraconazole, ketoconazole, lidocaine (systemic), methadone, pimozide, quinidine, rifabutin, sildenafil, tacrolimus, vardenafil, warfarin. 

Nevirapine induces and is metabolized by CYP3A4 therefore, coadministration of drugs that induce or are metabolized by this isoenzyme may result in interactions. Nevirapine may decrease the effectiveness of ethinyl estradiol-based contraceptives and can lower plasma concentrations of methadone. Nevirapine should not be administered with ketoconazole, rifampin, or rifabutin. 

Nevirapine is a moderate inducer of CYP3A metabolism, resulting in decreased levels of amprenavir, indinavir, lopinavir, saquinavir, efavirenz, and methadone (Table 49-4). Drugs that induce the CYP3A system, such as tipranavir, rifampin, rifabutin, and St. John s wort, can decrease levels of nevirapine, whereas those that inhibit CYP3A activity, such as fluconazole, ketoconazole, and clarithromycin, can increase nevirapine levels. 

T effects OF amiodarone, astemizole, atorvastadn, barbiturates, bepridil, bupropion, cerivastatin, cisapride, clorazepate, clozapine, clarithromycin, desipramine, diazepam, encainide, ergot alkaloids, estazolam, flecainide, flurazepam, indinavir, ketoconazole, lovastatin, meperidine, midazolam, nelfinavir, phenytoin, pimozide, piroxicam, propafenone, propoxyphene, quinidine, rifabutin, saquinavir, sildenafil, simvastatin, SSRIs, TCAs, terfenadine, triazolam, troleandomycin, zolpidem X effects W/ barbiturates, carbamazepine, phenytoin, rifabutin, rifampin, St. John s wort, tobacco X effects OF didanosine, hypnotics, methadone, OCPs, sedatives, theophylline, warfarin EMS T Effects of amiodarone, diazepam, midazolam and BBs, may need X- doses concurrent use of Viagra-type drugs can lead to hypotension X- effects of warfarin concurrent EtOH use can T adverse effects T glucose ODs May cause an extension of adverse SEs symptomatic and supportive Rivasrigmine (Exelon) [Cholinesterase Inhibitor/Anri ... 

The drugs that induce cytochrome P-450 system isoenzyme CYP3A4 will inhibit the blood levels of amprenavir. It decreases the plasma levels of methadone and delavirdine and increases the plasma levels of rifabutin, ketoconazole and atorvas-tatin. This may be the result of the ability of amprenavir to inhibit as well as induce CYP3A4. 

OPIOIDS ANTIFUNGALS 1, Ketoconazole T effect of buprenorphine 2. Fluconazole and itraconazole T the effect of alfentanil 3. Fluconazole and possibly voriconazole T effect of methadone this is a recognized pharmacokinetic effect but of uncertain clinical significance 1. Ketoconazole 1 the CYP3A4-mediated metabolism of buprenorphine 2.1 clearance of alfentanil 3.1 hepatic metabolism 1. The dose of buprenorphine needs to be 1 (by up to 50%) 2. i dose of alfentanil 3. Watch for T effects of methadone... 

Clinically important, potentially hazardous interactions with alfentanil, aminophylline, amisulpride, amoxicillin, ampicillin, anticonvulsants, astemizole, atorvastatin, benzodiazepines, bromocriptine, buprenorphine, bupropion, carbamazepine, cilostazol, ciprofloxacin, cisapride, clindamycin, colchicine, cyclosporine, dasatinib, digoxin, dihydroergotamine, diltiazem, disopyramide, enoxacin, eplerenone, ergotamine, eszopiclone, everolimus, fluconazole, fluoxetine, fluvastatin, gatifloxacin, HMG-CoA reductase inhibitors, imatinib, itraconazole, ketoconazole, lomefloxacin, lorazepam, lovastatin, methadone, methylprednisolone, methysergide, midazolam, mizolastine, moxifloxacin, nitrazepam, norfloxacin, ofloxacin, paroxetine, pimozide, pravastatin, quinolones, ranolazine, repaglinide, rupatadine, sertraline, sildenafil, simvastatin, sparfloxacin, sulpiride, tacrolimus, terfenadine, triazolam, troleandomycin, vardenafil, verapamil, vinblastine, warfarin, zaleplon, zolpidem, zuclopenthixol... 

Clinically important, potentially hazardous interactions with abacavir, atorvastatin, bepridil, bupropion, carbamazepine, clarithromycin, cyclosporine, dexamethasone, digoxin, felodipine, fluticasone propionate, fosamprenavir, itraconazole, ketoconazole, lovastatin, methadone, midazolam, nicardipine, nifedipine, phenobarbital, phenytoin, rifabutin, simvastatin, sirolimus, St John s wort, systemic lidocaine, tacrolimus, tenofovir, trazodone, vinblastine, vincristine, voriconazole, warfarin, zidovudine... 

Acetaminophen, aldrin, alfentanil, amiodarone, aminopyrine, amitriptyline, amprenavir, androstenedione,antipyrine, astemizole, benzphetamine, budesonide, carbamazepine, celecoxib, chlorpromazine, chlorzoxazone, cisapride, clarithromycin, clozapine, cocaine, codeine, cortisol, cyclophosphamide,cyclosporin, dapsone, delavirdine, dextromethorphan, digitoxin, diltiazem, diazepam, erythromycin, 17j3-estradiol, ethinylestradiol, etoposide, felbamate, fentanyl, flutamide, hydroxyarginine, ifosphamide, imipramine, indinavir, ketoconazole, lansoprazole, loratidine, losartan, lovastatin, (iS)"mephen3d in, methadone, mianserin, miconazole, mifepristone, nelfinavir, nevirapine, nicardipine, nifedipine, odansetron, omeprazole, orphenadrine, proguanil, propafenone, quinidine, quinine, rapamycin, retinoic acid, ritonavir, saquinavir, selegiline, serindole, sufentanil, sulfinpyrazone, tacrolimus, tamoxifen, tamsulosin, taxol, teniposide, terfenadine, tetrahydrocannabinol, theophylline, toremifene, triazolam, trimethadone, trimethoprim, troleandomycin, verapamil, warfarin, zatosetron, Zolpidem, zonisamide... 

Also analyzed acebutolol, acepromazine, acetaminophen, acetazolamide, acetophenazine, albuterol, amitriptyline, amobarbital, amoxapine, antipsrrine, atenolol, atropine, azata-dine, baclofen, benzocaine, bromocriptine, brompheniramine, brotizolam, bupivacaine, buspirone, butabarbital, butalbital, caffeine, carbamazepine, cetirizine, chlorqyclizine, chlordiazepoxide, chlormezanone, chloroquine, chlorpheniramine, chlorpromazine, chlorpropamide, chlorprothixene, chlorthalidone, chlorzoxazone, cimetidine, cisapride, clomipramine, clonazepam, clonidine, clozapine, cocaine, codeine, colchicine, qyclizine, (yclo-benzaprine, dantrolene, desipramine, diazepam, diclofenac, diflunisal, diltiazem, diphenhydramine, diphenidol, dipheno late, dipyridamole, disopyramide, dobutamine, doxapram, doxepin, droperidol, encainide, ethidium bromide, ethopropazine, fenoprofen, fentanyl, flavoxate, fluoxetine, fluphenazine, flurazepam, flurbiprofen, fluvoxamine, fii-rosemide, glutethimide, glyburide, guaifenesin, haloperidol, homatropine, hydralazine, hydrochlorothiazide, hydrocodone, hydromorphone, hydro g chloroquine, hydroxyzine, ibuprofen, imipramine, indomethacin, ketoconazole, ketoprofen, ketorolac, labetalol, le-vorphanol, lidocaine, loratadine, lorazepam, lovastatin, loxapine, mazindol, mefenamic acid, meperidine, mephenytoin, mepivacaine, mesoridazine, metaproterenol, methadone, methdilazine, methocarbamol, methotrexate, methotrimeprazine, methoxamine, methyl-dopa, methylphenidate, metoclopramide, metolazone, metoprolol, metronidazole, midazolam, moclobemide, morphine, nadolol, nalbuphine, naloxone, naphazoline, naproxen, nifedipine, nizatidine, norepinephrine, nortriptyline, oxazepam, oxycodone, oxymetazo-line, paroxetine, pemoline, pentazocine, pentobarbital, pentoxifylline, perphenazine, pheniramine, phenobarbital, phenol, phenolphthalein, phentolamine, phenylbutazone, phenyltoloxamine, phenytoin, pimozide, pindolol, piroxicam, pramoxine, prazepam, prazosin, probenecid, procainamide, procaine, prochlorperazine, procyclidine, promazine, promethazine, propafenone, propantheline, propiomazine, propofol, propranolol, protriptyline, quazepam, quinidine, quinine, racemethorphan, ranitidine, remoxipride, risperidone, salicylic acid, scopolamine, secobarbital, sertraline, sotalol, spironolactone, sulfinpyrazone, sulindac, temazepam, terbutaline, terfenadine, tetracaine, theophylline, thiethyl-perazine, thiopental, thioridazine, thiothixene, timolol, tocainide, tolbutamide, tolmetin, trazodone, triamterene, triazolam, trifluoperazine, triflupromazine, trimeprazine, trimethoprim, trimipramine, verapamil, warfarin, xylometazoline, yohimbine, zopiclone... 

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