Clarithromycin 4- .Antacids

Drugs that may affect delavirdine include the following Anticonvulsants, antacids, clarithromycin, didanosine, fluoxetine, histamine H2 antagonists, ketoconazole,... 

Drugs that may affect tipranavir include aluminum- and magnesium-based antacids, azole antifungals, clarithromycin, efavirenz, loperamide, NRTIs (ie, didanosine, zidovudine), rifamycins (rifampin), St. John s wort, tenofovir. 

Drugs that might affect amprenavir include abacavir, aldesleukin, antacids, anticonvulsants, azole antifungals, clarithromycin, cyclosporine, dexamethasone, buffered didanosine, disulfiram, ethanol, indinavir, methadone, metronidazole, nelfinavir, nonnucleoside reverse transcriptase inhibitors, oral contraceptives, rifamycins, ritonavir, saquinavir, St. John s wort, tacrolimus, and zidovudine. 

Drugs that may affect atazanavir include the following antacids and buffered medications, clarithromycin, didanosine (buffered formulation only), efavirenz, H2-receptor antagonists, indinavir, itraconazole, ketoconazole, nevirapine, proton pump inhibitors, rifampin, ritonavir, St. John s wort, tenofovir, voriconazole. 

NA /D, abd pain, bleeding, fevCT, T QT Interactions t Effects W7 atazanavir, clarithromycin, CT5rthromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfi-navir, ritonavir, saquinavir, telithromycin X effects W7 antacids, carbamazqjine, dexamethasone, phenobarbital, phenytoin, rifampicin, St. John s wort EMS Drug contains lactose, may cause D/abd discomfort in pts w/ lactose intolerance OD Sxs unknown symptomatic and supportive... 

Deravirdine (Rescnptor) [Antiretroviral/NNRTI] Uses HIV Infxn Action Nonnucleoside RT inhibitor Dose 400 mg PO tid Caution [C, ] CDC recommends HIV-infected mothers not to breast-feed (transmission risk) w/ renal/hepatic impair Contra Use w/ drugs dependent on CYP3A for clearance (Table VI-8) Disp Tabs SE Fat redistribution, immune reconstitution synd, HA, fatigue, rash, T transaminases, N/V/D Interactions T Effects W/ fluoxetine T effects OF benzodiazepines, cisapride, clarithromycin, dapsone, ergotamine, indinavir, lovastatin, midazolam, nifedipine, quinidine, ritonavir, simvastatin, terfena-dine, triazolam, warfarin effects W/ antacids, barbiturates, carbamazepine, cimetidine, famotidine, lansoprazole, nizatidine, phenobarbital, phenytoin, ranitidine, rifabutin, rifampin effects OF didanosine EMS Use of benzodiazepines and CCBs should be avoided may cause a widespread rash located on upper body and arms OD May cause an extension of nl SEs symptomatic and supportive Deferasirox (Exjade) [Iron Chelator] Uses Chronic iron overload d/t transfusion in pts >2 y Action Oral iron chelator Dose Initial 20 mg/kg... 

Prednisolone [Corticosteroid] [See Steroids and Table VI-1] Interactions T Effects W/ clarithromycin, erythromycin, estrogen, ketoconazole, OCPs, troleandomycin X effects W/ antacids, aminoglutethimide, barbiturates, cholestyramine, colestipol, phenytoin, rifampin X effects OF anticoagulants, hypoglycemics, INH, salicylates, vaccine toxoids EMS Infxns may be masked OD May cause wt gain, T hair growth, acne, HTN, peripheral edema, and sore muscles symptomatic and supportive... 

Azithromycin is rapidly absorbed and well tolerated orally. It should be administered 1 hour before or 2 hours after meals. Aluminum and magnesium antacids do not alter bioavailability but delay absorption and reduce peak serum concentrations. Because it has a 15-member (not 14-member) lactone ring, azithromycin does not inactivate cytochrome P450 enzymes and therefore is free of the drug interactions that occur with erythromycin and clarithromycin. 

Delavirdine is extensively metabolized to inactive metabolites by the CYP3A and CYP2D6 enzymes. However, it also inhibits CYP3 A and thus inhibits its own metabolism. In addition to its interactions with other antiretroviral agents (see Table 49 1), delavirdine will result in increased levels of numerous agents (Table 49-3). Dose reduction of indinavir and saquinavir should be considered if they are administered concurrently with delavirdine. Delavirdine plasma concentrations are reduced in the presence of antacids, phenytoin, phenobarbital, carbamazepine, rifabutin, and rifampin concentrations are increased during coadministration with clarithromycin, fluoxetine, dexamethasone, and ketoconazole. 

Clinically important, potentially hazardous interactions with aminophylline, amprenavir, antacids, carbamazepine, carmustine, chlorpheniramine, clarithromycin, efavirenz, esomeprazole, imatinib, indinavir, itraconazole, ketoconazole, MAO inhibitors, midazolam, modobemide, nelfinavir, phenytoin, sucralfate, warfarin... 

Amoxicillin, clarithromycin, tetracycline, and metronidazoie have been used in various regimens for H. fy/on-associated GI ulcers, together with H2 blockers, proton pump inhibitors, and antacids e.g., "BMI" regimen bismuth, metronidazole, and tetracycline. 

Studies of the concomitant use of azithromycin with carbamazepine, terfenadine, and zidovudine have not reported drug interactions [131-133]. With the potential exception of antacids, no drug interactions have been reported with azithromycin, which does not appear to be metabolized by the cytochrome P-450 system [4, 134], Both azithromycin and clarithromycin have been associated with digoxin toxicity. The postulated mechanism is by eradication of Eubacterium lentum, an anaerobic gram-positive bacteria responsible for the metabolism of digoxin in some patients [43]. 

Drug interactions occur between tipranavir and fluconazole and between tipranavir and clarithromycin, increasing the AUC over a 12 hour period for tipranavir by 56 and 59%, respectively. Care should be taken when administering tipranavir with CYP450 inhibitors and inducers, because clinically significant interactions are possible. Coadministration of tipranavir with antacids decreases the tripranavir AUC by up to 33%. 

Aluminium/magnesium hydroxide antacids are reported not to affect the pharmacokinetics of clarithromycin, roxithromycin, or telithro-mycin. 

Ziindorf H, Wischmann L, Fassenbender M, Lode H, Bc ner K, Koe P Pharmacokinetics of clarithromycin and possible interacticxi with H blockers and antacids Intersd ConfAntimi-crob Agents Chemother( 99 )3, 185. 

Aluminium/magnesium hydroxide antacids may reduce the peak levels of azithromycin. Mylanta can prolong the absorption of erythromycin, but this is unlikely to be clinically important Aluminium/magnesium hydroxide antacids do not appear to significantly alter the pharmacokinetics of clarithromycin, roxithromycin or telithromycin. 

---