SEVERAL COMPOUNDS ARE INHIBITORS OF CYP2A6-MEDIATED NICOTINE METABOLISM IN VITRO, INCLUDING METHOXSALEN, TRYPTAMINE AND COUMARIN. A FEW DRUGS LIKE RIFAMPICIN, ORAL CONTRACEPTIVES, DEXAMETHASONE AND PHENOBARBITAL,HAVE BEEN SHOWN TO INDUCE CYP2A6 ENZYME & HENCE NICOTINE METABOLISM. PHARMACODYNAMIC INTERACTIONS MAY ALTER THE EXPECTED RESPONSE OR ACTIONS OF OTHER DRUGS. THIS SHOULD BE KEPT IN MIND WHEN PRESCRIBING NICOGUM CHEWING GUM WITH DRUGS LIKE SEDATIVES, OPIOIDS, ANTIHYPERTENSIVES, INSULIN, THEOPHYLLINE, ORAL CONTRACEPTIVES, AND CAFFEINE.