Doxorubicin Barbiturates

Drugs that may affect barbiturates include alcohol, charcoal, chloramphenicol, MAO inhibitors, rifampin, and valproic acid. Drugs that may be affected by barbiturates include acetaminophen, anticoagulants, beta blockers, carbamazepine, chloramphenicol, clonazepam, oral contraceptives, corticosteroids, digitoxin, doxorubicin, doxycycline, felodipine, fenoprofen, griseofulvin, hydantoins, methoxyflurane, metronidazole, narcotics, phenmetrazine, phenylbutazone, quinidine, theophylline, and verapamil. 

Phenobarbital and other barbiturates1 Barbiturates, chloramphenicol, chlorpromazine, cortisol, coumarin anticoagulants, desmethylimipramine, digitoxin, doxorubicin, estradiol, phenylbutazone, phenytoin, quinine, testosterone... 

Morphine Sulfate Morphine sulfate precipitates in alkaline media and drugs that are incompatible with it, including aminophylline, sodium salts of barbiturates, and phenytoin. Precipitate was found after 2 horns when morphine sulfate was formulated with acyclovir sodium.70 Incompatibilities also are reported with chlorpromazine hydrochloride injections containing chlorocresol. Admixture of morphine sulfate (1 mg/mL), doxorubicin in doxorubicin hydrochloride... 

Pethidine Hydrochloride Pethidine hydrochloride solutions are not compatible with barbiturates, aminophylline, morphine sulfate, sulfadiazine sodium, methicilline sodium, nitrofurantoin, phenytoin sodium, heparin sodium, sodium iodide, diethanolamine, sulfafurazol, acyclovir sodium, liposomal doxorubicin hydrochloride, frusemide, imipenem, and idarubicin. Visual incompatibilities are reported with mixtures of pethidine hydrochloride and cefoperazone sodium or mezlocillin sodium, nafcillin sodium and minocycline hydrochloride or tetracycline hydrochloride in 5% glucose injection.82 83... 

DOXORUBICIN ANTIEPILEPTICS -BARBITURATES i doxorubicin levels Induction of hepatic metabolism Monitor for 1 efficacy of doxorubicin... 

C9 Barbiturates, especially phenobarbital, phenytoin, primidone, rifampin Barbiturates, chloramphenicol, doxorubicin, ibuprofen, phenytoin, chlorpromazine, steroids, tolbutamide, warfarin... 

A4 Barbiturates, carbamazepine, corticosteroids, efavirenz, phenytoin, rifampin, troglitazone Antiarrhythmics, antidepressants, azole antifungals, benzc iazepines, calcium channel blockers, cyclosporine, delavirdine, doxorubicin, efavirenz, erythromycin, estrogens, HIV protease inhibitors, nefazodone, paclitaxel, proton pump inhibitors, HMG-CoA reductase inhibitors, rifabutin, rifampin, sildenafil, SSRIs, tamoxifen, trazodone, vinca anticancer agents... 

A comparative study in patients given doxorubicin found that those also taking barbiturates had a plasma clearance that was 50% higher than those who were not (318 mL/minute eompared with 202 mL/minute). This olinieal study is in agreement with previous studies in mice A possible explanation is that the barbiturate inereases the metabolism of the doxoru-biein. It seems possible that the dosage of doxorubiein will need to be inoieased in barbiturate-treated patients to aehieve maximal therapeutie effeets. 

Ri s CE, Ei el S, Wesley M, Wiemik PH, Bachur NR. Doxorubicin pharmacokinetics prodilorpeiBzine and barbiturate effects. Clin Pharmacol Ther( 9 )3, 263. 

Vitamin A inhibited doxorubicin-induced membrane lipid peroxidation in rat tissue in vivo (CiAC-cio et al. 1993). Brain and heart membrane preparations from rats receiving vitamin A, assayed in vitro in the presence of a Fe " ascorbate induction system, showed a delay in the beginning of the lipid peroxidation and generated lesser amounts of thio-barbituric acid reactive substances, with respect in membranes from control rats. 

Paclitaxel is metabolized by CYP2C8 and CYP3A4 [23, 83 ], and drugs that inhibit or induce these isoenzymes would be expected to alter the metabolism of paclitaxel. In vitro ranitidine, diphenhydramine, vincristine, vinblastine, and doxorubicin had little or no effect on the metabolism of paclitaxel, but barbiturates stimulated hydroxylation of the side-chain by induction of CYP3A isoforms [83 ]. Although cimeti-dine and famotidine have quite different CYP-modulating abilities, a clinical study showed no difference in paclitaxel clearance or associated neutropenia when cimetidine or famotidine were used as part of the premedication regimen [84 ]. 

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