17. Current administration of a known potent CYP1A2 inhibitor, including zileuton (Zyflo), ciprofloxacin, enoxacin or any other fluoroquinolone antibiotic, amiodarone, mexiletine, propafenone, verapamil, cimetidine (Tagamet), famotidine (Pepcid), oral contraceptives, acyclovir (Zovirax) and ticlopidine (Ticlid) (Horn & Hansten, 2008).