EMSAM is marketed by Bristol-Myers Squibb Co and manufactured by Somerset Pharmaceuticals Inc. It is available in 3 strengths: 6 mg/24 hr, 9 mg/24 hr, and 12 mg/24 hr. Monoamine oxidase exists as 2 isoforms, MAO-A and MAO-B. Selegiline has greater affinity for MAO-B but at antidepressant doses inhibits both isoenzymes. Although the exact mechanism is not fully understood, the inhibition of both MAO-A and MAO-B is believed to potentiate activity of monoamine transmitters in the brain such as serotonin, norepinephrine, and dopamine. As demonstrated in animal models, EMSAM 6 mg/24 hr allows for antidepressant concentrations of selegiline to be achieved in the brain while preserving adequate MAO-A in the GI tract to break down tyramine. Thus there are no dietary restrictions at the starting and target doses of 6 mg/24 hr. Due to limited data for EMSAM 9 mg/24 hr and 12 mg/24 hr, to reduce the risk of hypertensive crisis, dietary tyramine modifications are required at these doses. Patients using the 9-mg/24-hr and the 12-mg/24-hr patches must follow dietary tyramine modification beginning the first day of treatment with these doses and for 2 weeks after discontinuing the patches or reducing the dose to 6mg/24 hr. Examples of foods and drinks to avoid include meat, poultry, or fish that has been aged, fermented, spoiled, pickled, or improperly stored broad bean pods aged cheeses tap or unpasteurized beers concentrated yeast extracts sauerkraut soy products and OTC tyramine products.