Carbamazepine Bupropion

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... 

Clinically important, potentially hazardous interactions with alfentanil, alfuzosin, alprazolam, amiodarone, amprenavir, aprepitant, astemizole, atazanavir, bepridil, buprenorphine, bupropion, carbamazepine, chlordiazepoxide, ciclesonide, clozapine, conivaptan, cyclosporine, cyproterone, dasatinib, diazepam, dihydroergotamine, ergot alkaloids, estazolam, eszopidone, etravirine, ezetimibe, fentanyl, fesoterodine, flecainide, flurazepam, fluticasone, halazepam, ivabradine, ixabepilone, ketoconazole, lapatinib, levothyroxine, meperidine, meptazinol, methysergide, midazolam, nifedipine, nilotinib, oral contraceptives, phenytoin, pimozide, piroxicam, propafenone, propoxyphene, quazepam, quinidine, ranolazine, rifabutin, rifampin, rifapentine, rimonabant, rivaroxaban, saquinavir, sildenafil, silodosin, simvastatin, solifenacin, St John s wort, tadalafil, temsirolimus, trabectedin, triazolam, vardenafil, voriconazole, zolpidem... 

Simultaneous amoxapine, clovoxamine, desipramine, fenfluramine, fluvoxamine, nor-fluoxetine, nortriptyline, propranolol, protriptyline, sertraline Noninterfering amitriptyline, atenolol, bupropion, carbamazepine, chlordiazepoxide, ci-talopram, clomipramine, clozapine, cyclobenzaprine, doxepin, imipramine, loxapine, me-toprolol, mianserin, moclobemide, nomifensine, pindolol, thioridazine, tranyl[Pg.626]

Carbamazepine and possibly the antidepressant mirtazapine should not be coadministered with clozapine because these drugs may further increase the risk of agranulocytosis. In addition, the antidepressant bupropion should not be coprescribed with clozapine because it may increase clozapine s seizure risk. 

Care should be taken when prescribing other medications with clozapine. The mood stabilizer carbamazepine (Tegretol) and perhaps the antidepressant mirtazap-ine (Remeron) should not be taken with clozapine because they might further increase the risk of agranulocytosis. Likewise, the antidepressant bupropion (Wellbutrin, Zyban) should not be taken with clozapine because it may add to the seizure risk. 

Drugs that may affect bupropion include amantidine, levodopa, carbamazepine, MAOIs, nicotine replacement, and ritonavir. 

Drugs that can decrease carbamazepine serum levels include charcoal, cisplatin, doxorubicin, felbamate, hydantoins, rifampin, phenobarbital, primidone, theophylline. The serum levels of oral contraceptives, haloperidol, bupropion, anticoagulants, felbamate, valproic acid, felodipine, tricyclic antidepressants, acetaminophen, ziprasidone, voriconazole, topiramate, tiagabine, olanzapine, and lamotrigine can be lowered by carbamazepine. 

Because bupropion is extensively metabolized, the coadministration of other drugs may affect its clinical activity. In particular, certain drugs may induce the metabolism of bupropion (eg, carbamazepine, phenobarbital, phenytoin) while other drugs may inhibit the metabolism of bupropion (eg, cimetidine, ritonavir). 

Because bupropion is metabolized in the liver, medications that alter hepatic enzyme metabolism, such as carbamazepine or cimetidine, may effect blood concentrations. Bupropion should not be administered in combination with the MAOIs because of risk of hypertensive crisis. Levo-dopa use in conjunction with bupropion has been associated with confusion, hallucinations, and dyskinesia. Although generally well tolerated, there are case reports documenting that the... 

According to the Expert Consensus Panel for Mental Retardation Rush and Frances, (2000), the mainstays of the pharmacological treatment of acute mania or bipolar disorder in adults are anticonvulsant medications (divalproex, valproic acid, or carbamazepine) or lithium. Both divalproex or valproic acid and lithium were preferred treatments for classic, euphoric manic episodes. Divalproex or valproic acid was preferred over lithium and carbamazepine for mixed or dysphoric manic episodes and rapid-cycling mania. For depressive episodes associated with bipolar disorder, the addition of an antidepressant (SSRI, bupropion, or venlafaxine) was recommended. According to the Expert Consensus Panel, the presence of MR does not affect the choice of medication for these psychiatric disorders in adults. 

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 ... 

At this time, the preferred first-line drug therapy for ADHD is either methylphenidate, dexmethylphenidate, mixed amphetamine salts, or dextroamphetamine. Atomoxetine, bupropion, or TCAs are good options for those umesponsive to or unable to tolerate stimulants. Clonidine and guanfacine are third-line options or adjuncts that require careful cardiovascular monitoring. Mood stabilizers (e.g., lithium, divalproex, and carbamazepine) and atypical antipsychotics are adjuncts for control of aggression or comorbid bipolar disorder. Other agents require further investigation before their status in the treatment of ADHD can be fuUy determined. 

I Drug-Drug Interactions. Carbamazepine induces the hepatic cytochrome P450 isoenzymes (1A2, 3A4, 2C9/10, and 2D6), which increases the metabolism of many medications, such as anticonvulsants (i.e., lamotrigine, topiramate, and valproate), antidepressants (i.e., tricyclics and bupropion), antipsychotics (i.e., clozapine, haloperi-dol, fluphenazine, olanzapine, and thiothixene), benzodiazepines, oral contraceptives, and protease inhibitors. " Women who receive carbamazepine require higher dosages of oral contraceptives or alternative contraceptive methods." ... 

CYP2B6 <5 1-2 Bupropion Carbamazepi ne Cyclophosphamide Selegiline Flunitrazepam Meperidine Bupropion Selegiline Ethinylestradiol Phencyclidine Tamoxifen Ticlopidine Clotrimazole Carbamazepine Phenobarbital Phenytoin Pioglitazone Rifampin Troglitazone Valproic acid Ritonavir... 

Anticonvulsants Carbamazepine decreases the plasma concentration of bupropion to about 90% even after a single dose of 150 mg of carbamazepine. Long-term administration of valproate (a weak inhibitor of hepatic metabolism) has no effect on bupropion plasma concentration. It has been shown that bupropion does not cause clinically relevant changes in the pharmacokinetics of a single dose of 100 mg of lamotrigine. 

Carbamazepine induces hepatic catabolic enzymes, with a consequent reduction in serum levels of antidepressants (mainly described with amitriptyline, desipramine, doxepin, imipramine, mianserin, and nortriptyline). A decrease in bupropion serum levels was also reported with carbamazepine. These effects were not observed with clomipramine. Fluoxetine and fluvoxamine inhibit the metabolism of carbamazepine and valproate (up to 30% and 50% increases in serum levels, respectively). No significant interaction has yet been found between paroxetine and carbamazepine or valproate. 

Carbamazepine decreases bupropion levels and increases the levels of its active metabolite hydroxybupropion. Phenobarbital and phenytoin are predicted to interact similar. The concurrent use of bupropion and valproate has led to increased levels of valproate and hydroxybupropion, and hallucinations have been reported in patients taking both drugs. Hypomania has been reported in a patient taking bupropion and lamotiigine. 

One study found that carbamazepine at steady-state decreased the maximum plasma levels and AUC of bupropion and two of its metabolites (threohydrobupropion and erythrohydrobupropion) by about 81 to 96%. These two metabolites have only weak potential antidepressant activities. However, the AUC of another metabolite, hydroxybupropion (which has similar potency to the parent compound) was increased by 50% and its maximum plasma levels by 71%. Two patients with bipolar illness have been described who were initially given bupropion 450 mg daily, later increased up to 600 mg daily. They had undetectable bupropion plasma levels while taking carbamazepine but their plasma levels of hydroxybupropion were markedly increased. ... 

Ketter TA, Jenkins JB, Schroeder DH, Pazzaglia PJ, Marangell LB, George MS, Callahan AM, Hinton ML, Chao J, Post RM Carbamazepine but not valproate induces bupropion metabolism. J Clin Psychopharmacol (1995) 15, 327-33. 

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