One obstacle in the drug design process is the prevention of drug interactions that trigger harmful or unwanted effects to the human body. In fact, drug manufacturers go to great extents in determining what combinations of drugs or food sources in the diet should be avoided to circumvent such adverse effects. Cytochrome P450 3A4 (Cyp3A4) is an enzyme that is present in the liver and intestine. It is responsible for the conversion of ~50% of pharmaceutical agents, leading to the elimination of drugs from the body. Due to the promiscuous nature of substrate recognition and diversity of chemical transformations that Cyp3A4 is capable of catalyzing, this enzyme is responsible for many drug interactions. One example is the interaction of certain antihistamines in the presence of flavonoids found in grapefruit juice, leading to inhibitory effects on Cyp3A4 and documented deaths due to increased drug bioavailability. In our laboratory, drug interactions involving benzodiazepines that influence Cyp3A4 activity are being investigated. We measure changes in the enzyme kinetics, molecular recognition, and atomistic-level structural changes that occur in such situations. A prime example is the interaction of the drug Flunitrazepam ("roofies") with ethanol, a situation that occurs in drug-facilitated sexual assault. Students working on this project have an opportunity to study enzyme kinetics, molecular recognition, and atomistic changes that occur upon protein-ligand interactions, particularly in ternary complexes involving allosteric modulators.