Phenytoin Clarithromycin

In patients allergic to penicillin, macrolides are usually indicated in mild respiratory tract infections. Zithromax contains azithromycin, which is a macrolide that may be indicated for respiratory tract infections. As opposed to clarithromycin (another macrolide), azithromycin does not present any significant clinical interaction with phenytoin. Ciproxin contains ciprofloxacin. 

Drugs that may affect repaglinide include CYP 450 inhibitors (eg, clarithromycin, erythromycin, ketoconazole, miconazole), CYP 450 inducers (eg, barbiturates, carbamazepine, rifampin), beta blockers, calcium channel blockers, chloramphenicol, corticosteroids, coumarins, estrogens, gemfibrozil, isoniazid, itraconazole, levonorgestrel and ethinyl estradiol, MAOIs, nicotinic acid, NSAIDs, oral contraceptives, phenothiazines, phenytoin, probenecid, salicylates, simvastatin, sulfonamides, sympathomimetics, thiazides and other diuretics, and thyroid products. 

Drugs that may affect aprepitant include CYP 3A4 inhibitors (eg, clarithromycin, diltiazem, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, troleandomycin), CYP3A4 inducers (eg, carbamazepine, phenytoin, rifampin), and paroxetine. 

Drugs that may be affected by proton pump inhibitors include azole antifungal agents (eg, itraconazole, ketoconazole), benzodiazepines, cilostazol, clarithromycin, digoxin, phenytoin, salicylates, sulfonylureas, and warfarin. Drugs that may affect proton pump inhibitors include sucralfate and clarithromycin. 

Drugs that may affect zidovudine include acetaminophen, atovaquone, bone marrow suppressive/cytotoxic agents (eg, adriamycin, dapsone), clarithromycin, doxorubicin, fluconazole, ganciclovir, methadone, nelfinavir/ritonavir, phenytoin, probenecid, ribavirin, rifamycins, stavudine, trimethoprim, and valproic acid. 

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. 

Drugs that may affect tacrolimus include nephrotoxic agents (aminoglycosides, amphotericin B, cisplatin, cyclosporine), antifungals, bromocriptine, calcium channel blockers, cimetidine, clarithromycin, danazol, diltiazem, erythromycin, methylprednisolone, metoclopramide, carbamazepine, phenobarbital, phenytoin, rifamycins, cisapride, chloramphenicol, metronidazole, nefazodone, omeprazole, protease inhibitors, macrolide antibiotics, fosphenytoin, and St. John s wort. 

Buspirone (BuSpar) [Anxiolytic] WARNING Closely monitor for worsening depression or emergence of suicidality Uses Short-term relief of anxiety Action Antianxiety antagonizes CNS serotonin receptors Dose Initial 7.5 mg PO bid T by 5 mg q2-3d to effect usual 20-30 mg/d max 60 mg/d Contra w/ MAOI Caution [B, /-] Avoid w/ severe hepatic/renal insuff Disp Tabs SE Drowsiness, dizziness, HA, N, EPS, serotonin synd, hostility, depression Notes No abuse potential or physical/psychologic d endence Interactions T Effects W/ erythromycin, clarithromycin, itraconazole, ketoconazole, diltiazem, verapamil, grapefruit juice effects W/ carbamazepine, rifampin, phenytoin, dexamethasone, phenobarbital, fluoxetine EMS T Sedation w/ concurrent EtOH use grapefruit juice may T risk of adverse effects OD May cause dizziness, miosis, N/V symptomatic and supportive... 

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... 

Others Acetaminophen, amiodarone, carbamazepine, delavirdine, efavirenz, nevirapine, quinidine, repaglinide, sildenafil, tadalafil, trazodone, vardenafil Amiodarone, amprenavir, atazanavir, ciprofloxacin, cisapride, clarithromycin, diltiozem, erythromycin, fluconazole, fluvoxamine, grapefruit juice (in high ingestion), indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, norfloxacin, ritonavir, telithromycin, troleandomycin, verapamil, voriconazole Carbamazepine, efavirenz, glucocorticoids, macrolide antibiotics, nevirapine, phenytoin, phenobarbital, rifabutin, rifapentine, rifampin, St. John s wort... 

Short-term management of insomnia Action Benzodiazepine Dose 1-2 mg PO qhs PRN X in hepatic impair/elderly/debilitated Caution [X, -] T Effects w/ CNS depressants Contra PRG Disp Tabs SE Somnolence, weakness, palpitations, anaphylaxis, angioedema, amnesia Interactions T Effects W/ amoxicillin, clarithromycin T effects OF diazepam, phenytoin, warfarin X effects W/ food X effects OF azole antifungals, digoxin EMS Use caution w/ other benzodiazepines, may need a reduced dose concurrent EtOH and caffeine use can T CNS effects OD May cause altered reflexes, drowsiness, CNS depression, slurred speech, and Szs flumazenil can be used as an antidote... 

Lopinavir/Ritonavir (Kaletra) [Anrirelroviral/Protease Inhibitor] Uses HIV Infxn Action Protease inhibitor Dose Adults. Tx naive 2 tab PO daily or 1 tab PO bid Tx experiencedpt 1 tab PO bid (T dose if w/ amprenavir, efavirenz, fosamprenavir, nelfinavir, nevirapine) Peds. 7-15 kg 12/3 mg/kg PO bid 15-40 kg 10/2.5 mg/kg PO bid >40 kg Adult dose w/ food Caution [C, /-] Numerous interactions Contra w/drugs dependent on CYP3A/CYP2D6 (Table VI-8) Disp Tab, soln SE Avoid disulfiram (soln has EtOH), metronidazole GI upset, asthenia, T cholesterol/triglycerides, pancreatitis protease metabolic synd Interactions T Effects Wl clarithromycin, erythromycin T effects OF amiodarone, amprenavir, azole andfungals, bepridil, cisapride, cyclosporine, CCBs, ergot alkaloids, flecainide, flurazepam, HMG-CoA reductase inhibitors, indinavir, lidocaine, meperidine, midazolam, pimozide, propafenone, propoxyphene, quinidine, rifabutin, saquinavir, sildenafil, tacrolimus, terfenadine, triazolam, zolpidem 1 effects Wl barbiturates, carbamazepine, dexamethasone, didanosine, efavirenz, nevirapine, phenytoin, rifabutin, rifampin, St. John s wort 1 effects OF OCPs, warfarin EMS Use andarrhythmics and benzodiazepines... 

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 ... 

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. 

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