Ketoconazole Antacids

Ketoconazole. For treatment of systemic mycoses with amphotericin B or miconazole, the patient must be admitted to a hospital. This is not always possible, particularly in areas where systemic mycoses occur frequently, nor is it always desirable, because of the expense. For these reasons, it was desirable to find an antimycotic that combined safety and broad-spectmm activity with oral adraiinistration. Ketoconazole (10), which is orally active, met most of these requirements. This inhibitor of the ergosterol biosynthesis is an A/-substituted imidazole, that differs from its precursors by the presence of a dioxolane ring (6,7). Ketoconazole is rapidly absorbed in the digestive system after oral adrninistration. Sufficient gastric acid is required to dissolve the compound and for absorption. Therefore, medication that affects gastric acidity (for example, cimetidine and antacids) should not be combined with ketoconazole. 

KETOCONAZOLE This drug is given with food to minimize gastrointestinal irritation. Tablets may be crushed. Ketoconazole is absorbed best in an acid environment. Do not administer antacids, anticholinergics, or histamine blockers until at least 2 hours after ketoconazole is given. 

Drugs that may affect benzodiazepines include alcohol, antacids, barbiturates, cimetidine, disulfiram, fluoxetine, isoniazid, ketoconazole, metoprolol, oral contraceptives, narcotics, probenecid, propoxyphene, propranolol, ranitidine, rifampin, scopolamine, theophylline, and valproic acid. 

Drugs that may affect ketoconazole include antacids, didanosine, histamine H2 antagonists, isoniazid, sucralfate, proton pump inhibitors, and rifampin. Drugs that may be affected by ketoconazole include oral anticoagulants, corticosteroids, cyclosporine, protease inhibitors, tricyclic antidepressants, carbamazepine. 

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. 

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

Aluminum Hydroxide + Magnesium Hydroxide (Maalox) [OTC] [Antacid/Aluminum Magnesium Salts] Uses Hyper-acidity (peptic ulcer, hiatal hernia, etc) Action Neutralizes gastric acid Dose Adults. 10-20 mL or 2-4 tabs PO qid or PRN Feds. 5-15 mL PO qid or PRN Caution [C, ] Disp Tabs, susp SE May cause t Mg in renal insuff, constipation, D Interactions In addition to AlOH, X effects OF digoxin, quinolones, phenytoin, Fe supl, ketoconazole EMS None OD May cause constipation, loss of appetite, painful urination, heart rhythm changes, muscle weakness, and peripheral edema 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... 

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... 

Ketoconazole Antacids, anticholinergic drugs, cimetidine, ranitidine Decreased absorption. 

Dicyclomine (Bentyl) [Anrimuscarinic, GI Anrispasmodic/ Anticholinergic] Uses Functional IBS Action Smooth-muscle relaxant Dose Adults. 20 mg PO qid T to 160 mg/d max or 20 mg EM q6h, 80 mg/d - qid then T to 160 mg/d, max 2 wk Feds. Infants >6 mo 5mg/dose tid-qid Children 10 mg/dose tid-qid Caution [B, -] Contra Infants <6 mo, NAG, MyG, severe UC, BOO Disp Caps, tabs, syrup, inj SE Anticholinergic SEs may limit dose Interactions T Anticholinergic effects W/ anticholinergics, antihistamines, amantadine, MAOIs, TCAs, phenothiazides T effects OF atenolol, digoxin X effects H7 antacids X effects OF haloperidol, ketoconazole, levodopa, phenothiazines EMS Avoid procainamide usage, may T adverse effects may T effects of digoxin, monitor... 

Ketoconazole (Nizoral) has a broad therapeutic potential for a number of superficial and systemic fungal infections. Ketoconazole dissolves in an acidic media therefore, antacids or histamine2-receptor-blocking agents reduce its effectiveness (Figure 45.3). Ketoconazole can cause gastrointestinal disturbances. 

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