Ritonavir Bupropion

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

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). 

Drugs that may increase the effects or side effects of bupropion include levodopa, MAOIs, ritonavir, antidepressants, antipsychotics, beta blockers, type 1C antiarrhythmics. 

Drugs that might be affected by lopinavir/ritonavir include ergot derivatives, oral contraceptives, antiarrhythmics, HMG-CoA reductase inhibitors, HIV protease inhibitors, atovaquone, calcium channel blockers, ketoconazole, itraconazole, pimozide, cisapride, clarithromycin, disulfiram, metronidazole, immunosuppressants, midazolam, triazolam, narcotic analgesics, rifabutin and rifabutin metabolite, sildenafil, warfarin, bupropion, clozapine, desipramine, piroxicam, quinidine, theophylline, and zolpidem. 

D6 Tricyclic antidepressants (TCAs), benztropine, perphenazine, clozapine, haloperidol, codeine/oxycodone, risperidone, class Ic antiarrhythmics, 3 blockers, trazodone, paroxetine, maprotiline, amoxapine, duloxetine, mirtazapine (partly), venlafaxine, bupropion Fluoxetine, paroxetine, duloxetine, hydroxybupropion, methadone, cimetidine, haloperidol, quinidine, ritonavir Phenobarbital, rifampin... 

PROTEASE INHIBITORS BUPROPION t adverse effects of bupropion with nelfinavir and ritonavir (with or without lopinavir) Possibly inhibition of CYP2B6-mediated metabolism of bupropion Avoid co-administration... 

Clinically important, potentially hazardous interactions with amiloride, aminoglycosides, amphotericin B, ampicillin, anisindione, anticoagulants, armodafinil, atorvastatin, azathioprine, azithromycin, bacampicillin, basiliximab, bezafibrate, bosentan, bupropion, carbenicillin, caspofungin, cholestyramine, clarithromycin, cloxacillin, co-trimoxazole, corticosteroids, cyclophosphamide, daclizumab, danazol, dicloxacillin, dicumarol, digoxin, diltiazem, disulfiram, echinacea, erythromycin, ethotoin, etoposide, ezetimibe, flunisolide, fluoxymesterone, fluvastatin, foscarnet, fosphenytoin, gemfibrozil, hemophilus B vaccine, HMG-CoA reductase inhibitors, imatinib, imipenem/cilastatin, influenza vaccines, ketoconazole, lanreotide, lopinavir, lovastatin, mephenytoin, methicillin, methoxsalen, methylphenidate, methylprednisolone, methyltestosterone, mezlocillin, mizolastine, mycophenolate, nafcillin, nisoldipine, NSAIDs, orlistat, oxacillin, penicillins, phellodendron, phenytoin, pravastatin, prednisolone, prednisone, pristinamycin, ranolazine, red rice yeast, rifabutin, rifampin, rifapentine, ritonavir, rosuvastatin, simvastatin, sirolimus, spironolactone, St John s wort, sulfacetamide, sulfadiazine, sulfamethoxazole, sulfisoxazole, sulfonamides, tacrolimus, telithromycin, tenoxicam, testosterone, ticarcillin, tolvaptan, trabectedin, triamterene, troleandomycin, ursodeoxycholic acid, vaccines, vecuronium, warfarin, zofenopril... 

Ritonavir Increased blood level of bupropion with increased risk of seizures... 

Ritonavir (RTV) Yes Alprazolam, Ethinyl Estradiol Product Monograph Yes Methadone Bupropion [50]... 

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... 

Ritonavir exhibits additive to synergistic effects against HIV when used in combination with reverse-transcriptase inhibitors such as zidovudine or zalcitabine. Ritonavir pro-dnces a large increase in the plasma concentration of amio-darone, astemizole, bepridil, bupropion, cisapride, clozapine, encainide, flecainide, meperidine, peroxicam, propafenone, propoxyphene, quinidine, rifabutin, and terfenadine. 

Ritonavir, efavirenz and nelfinavir inhibit the cytochrome P450 isoenzyme CYP2B6 in vitro and may, theoretically, increase bupropion levels. However, an in vivo study su ests that ritonavir may decrease bupropion levels. 

In contrast, the manufacturers of bupropion report a study in healthy subjects, in which ritonavir 600 mg twice daily for 20 days decreased the AUC and maximum serum levels of bupropion by about 65% and 60%, respectively. The plasma levels of the active metabolites of bupropion were also decreas. This contrasting information suggests that further study is needed. In the meantime, patients given bupropion with ritonavir should be monitored for increased bupropion effects and decreased bupropion effects. It would seem prudent to start bupropion at the lowest recommended dose and titrate to effect. 

Nervous system A 56-year-old HIV-1-positive woman who took raltegravir and etravirine for 3 days developed bilateral hand and foot tremors, followed by severe dysmetria and ataxia [137 ]. Etravirine and bupropion were withdrawn without relief of symptoms, which became disabling. An MRI scan of the brain and spinal cord with gadolinium was unremarkable. Raltegravir was replaced by ritonavir-boosted atazanavir and within 48 hours, her symptoms and physical findings resolved, without residual dysmetria or ataxia. 

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