Generic Biaxin should be avoided by patients known to be allergic to clarithromycin or other chemically similar macrolide antibiotics, such as erythromycin. Generic Biaxin can significantly increase blood levels of the active metabolite of terfenadine (Seldane) when these two medications are co-administered. Erythromycin, another macrolide antibiotic structurally similar to clarithromycin, has been known to interact with astemizole (Hismanal), loratadine (Claritin), bromocriptine, warfarin (Coumadin), carbamazepine (Tegretol), cyclosporine, digoxin (Lanoxin), disopyramide (Norpace), ergotamine, lovastatin (Mevacor), phenytoin (Dilantin), theophylline, triazolam (Halcion), and valproate to alter the blood levels of these medicines. Whether Generic Biaxin can interfere similarly with these medications is not clearly established.
Treatment with Generic Biaxin and other antibiotics can alter normal bacteria flora of the colon and permit overgrowth of C. difficile, a bacteria responsible for pseudomembranous colitis. Patients who develop pseudomembranous colitis as a result of antibiotics treatment can experience diarrhea, abdominal pain, fever, and sometimes even shock. Safe use with children has not been established. It is not habit forming.