Hi Lisa, purchase a bag of charcoal bbq briquettes (plain ones, NOT the ones to which fire starter has been added). Place the charcoal in small paper bags or an open container such as recycled yogurt, cottage cheese containers and place in the corners of the drawers. The charcoal will draw the odors into the charcoal. Another option that might help is sprinkling baking soda in the drawers for several days and then vacuuming out. Afterwards you might use just a few drops of pure tea tree oil on a cotton ball in the drawers. It is an antiseptic, and has a pungent, clean odor.
Place air fresher inside drawers..or scented dryer sheets
Spray surfaces with Concrobium Mold Control, sold at hardware stores. May require repeat applications.
Home Depot carries a product called OdoBan. Comes in a spray bottle or gallon size refill. It removes odor and disinfects. This product is AWESOME and even removed the stench of cat pee on a sofa! 😎