6. When MBT is performed subject should not have taken any of the following at least 48 hours prior to the breath test: Acyclovir , allopurinol, carbamazepine, cimetidine, ciprofloxacin, daidzein, (herbal) disulfiram, echinacea, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, montelukast, norfloxacin, phenylpropanolamine, phenytoin, propafenone, rifampin, terbinafine, ticlopidine, thiabendazole, verapamil, zileuton or any medication that might interfere with Methacetin metabolism or might affect CYP 1A2