Erythromycin drug interactions

As with erythromycin, drug interactions are extremely important with clarithromycin. Because clarithromycin inhibits the hepatic cytochrome P-450 system, it may result in increased levels of multiple medications metabolized by the liver [19]. Clarithromycin appeared to increase the mean steady-state plasma theophylline concentration and AUC from 15.6 p.g/ml and 249 pg hr/ml, respectively, in the absence of clarithromycin, to 18.4 pg/ml and 291 pg hr/ml in the presence of clarithromycin p< 0.001 for both concentration and AUC). Although a modest increase was seen in the plasma theophylline concentration, the concentration remained within the therapeutic range, and concurrent administration of clarithromycin and theophylline was safe and well tolerated [121]. Although the magnitude of elevation in theophylline was small, caution should be used when... 

Erythromycin Tablets 250, 500 mg 500 mg twice daily with food Maintenance dose 500 mg daily Gl intolerance, drug interactions... 

Erythromycin- sulfisoxazole 50 mg/kg per day of erythromycin component in 3 4 doses Nausea, vomiting, abdominal pain, diarrhea, rash SS Many drug interactions (like clarithromycin), contraindicated in children under 2 months increasing pneumococcal resistance... 

Drug interactions Metabolized by CYP450 3A4 (e.g., cyclosporine, erythromycin, itraconazole, phenytoin, St. John s wort)... 

Azithromycin Drugs that may interact with azithromycin include antacids, cyclosporine, HMG-CoA reductase inhibitors, pimozide, tacrolimus, theophyllines, and warfarin. Also consider all drug interactions with erythromycin. 

Because trimetrexate is metabolized by a P450 enzyme system, drugs that induce or inhibit this drug metabolizing enzyme system may elicit important drug interactions that may alter trimetrexate plasma concentrations, which include erythromycin, rifampin, rifabutin, ketoconazole, fluconazole, cimetidine, nitrogen substituted imidazole drugs (eg, clotrimazole, ketoconazole, miconazole). 

Carbamazepine also can induce the enzymes that metabolize other anticonvulsant drugs, including phenytoin, primidone, phenobarbital, valproic acid, clonazepam, and ethosuximide, and metabolism of other drugs the patient may be taking. Similarly, other drugs may induce metabolism of carbamazepine the end result is the same as for autoinduction, and the dose of carbamazepine must be readjusted. A common drug-drug interaction is between carbamazepine and the macrolide antibiotics erythromycin and trolean-domycin. After a few days of antibiotic therapy, symptoms of carbamazepine toxicity develop this is readily reversible if either the antibiotic or carbamazepine is discontinued. 

Ms. Jones takes fexofenadine 60 mg twice a day for seasonal allergies. She comes to her physician with a sinus infection and receives a prescription for erythromycin, a drug known to inhibit CYP3A4. As a result of this drug interaction, you would expect Ms. Jones to... 

Administration LEVITRA may require adjustment in patients receiving certain CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir, indinavir, and erythromycin) (see Warnings, Precautions Drug Interactions ). For ritonavir, a single dose of 2.5 mg LEVITRA should not be exceeded in a 72-hr period. For indinavir, ketoconazole 400 mg daily, and itraconazole 400 mg daily, a single dose of 2.5 mg LEVITRA should not be exceeded in a 24-hr period. For ketoconazole 200 mg daily, itraconazole 200 mg daily, and erythromycin, a single dose of 5 mg LEVITRA should not be exceeded in a 24-hr period... 

Concomitant administration of clarithromycin with cisapride, pimozide, astemizole, or terfenadine is contraindicated. There have been postmarketing reports of drug interactions when clarithromycin and/ or erythromycin are coadministered with cisapride, pimozide, astemizole, or terfenadine resulting in cardiac arrhythmias (QT prolongation, ventricular tachycardia, ventricular fibrillation, and torsades de pointes). 

Clarithromycin is metabolized in the liver. The major metabolite is 14-hydroxyclarithromycin, which also has antibacterial activity. A portion of active drug and this major metabolite is eliminated in the urine, and dosage reduction (eg, a 500-mg loading dose, then 250 mg once or twice daily) is recommended for patients with creatinine clearances less than 30 mL/min. Clarithromycin has drug interactions similar to those described for erythromycin. 

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. 

Drug Interactions Cyclosporine Gemfibrozil Niacin Erythromycin Cholestyramine/Colestipol Warfarin Cimetidine Digoxin ... 

Drug Interactions Gemfibrozil Niacin Erythromycin Cholestyramine Digoxin Cimetidine/ranitidine/ omeprazole Rifampicin Warfarin Itraconazole Gemfibrozil Niacin Erythromycin Propranolol Digoxin Warfarin Antacids Colestipol Digoxin Erythromycin Oral contraceptives Fibrates Niacin Azole antifungals... 

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