Drug interactions clarithromycin

Horton R, Barber C. Opioid-induced respiratory depression resulting from transdermal fentanyl-clarithromycin drug interaction in a patient with advanced COPD. / Pain Symptom Manage 2009 37 ... 

Assess the potential for drug interactions, particularly in patients taking regimens containing metronidazole, clarithromycin, and/or cimetidine. 

Clarithromycin 15 mg/kg per day in 2 doses (adult 250 mg twice daily) Diarrhea, vomiting, rash, abnormal taste, abdominal pain SJ Many drug interactions (inhibits cytochrome P-450 3A4) suspension cannot be refrigerated and has metallic taste same microbiologic issues as azithromycin... 

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... 

Tegretol consists of carbamazepine, which is an anti-epileptic drug. There is a clinically significant drug interaction between carbamazepine and clarithromycin (macrolide antibacterial agent) resulting in higher plasma concentrations of carbamazepine. 

The adverse effects that most frequently result in discontinuation of rifabutin include GI intolerance, rash, and neutropenia. Rifabutin levels will be increased with concurrent administration of fluconazole and clarithromycin, resulting in anterior uveitis, polymyalgia syndrome, and a yellowish-tan discoloration of the skin (pseudojaundice). Other adverse reactions are similar to those of rifampin, such as hepatitis, red-orange discoloration of body fluids, and drug interactions due to effects on the hepatic P450 cytochrome enzyme system. 

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. 

Bussing R, Gende A. Severe hypoglycemia from clarithromycin-sulfonylurea drug interaction. Diabetes Care 2002 25(9) 1659-61. 

Lee AJ, Maddix DS. Rhabdomyolysis secondary to a drug interaction between simvastatin and clarithromycin. Ann Pharmacother 2001 35(1) 26-31. 

Westphal JF. Macrolide-induced clinically relevant drug interactions with cytochrome P-450A (CYP) 3A4 an update focused on clarithromycin, azithromycin and dirithromycin. Br J Clin Pharmacol 2000 50 285-295. 

Gustavson LE, Chu SY, Mackenthun A, Gupta MS, Craft JC. Drug interaction between clarithromycin and oral zidovudine in HIV-1 infected patients. Clin Pharmacol Ther 1993 53 163. 

Which macrolide (erythromycin, clarithromycin, or azithromycin) may cause drug interactions with his current medications ... 

Drug interactions Erythromycin is a strong inhibitor of CYP450. CYP450 inhibition decreases with the newer maaolides. Thus, clarithromycin is a mild inhibitor, and azithromycin has no effect on aP450. 

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