Modafinil induces the cytochrome P450 enzymes CYP1A2 , CYP3A4 , and CYP2B6 , as well as inhibiting CYP2C9 and CYP2C19 in vitro .  It may also induce P-glycoprotein (Pgp), which may affect drugs transported by Pgp, such as digoxin . [ citation needed ] The bioavailability of modafinil is greater than 80% of the administered dose. In vitro measurements indicate that 60% of modafinil is bound to plasma proteins at clinical concentrations of the drug. This percentage actually changes very little when the concentration is varied.  C max (peak levels) occurs approximately 2–3 hours after administration. Food slows absorption, but does not affect the total AUC [ clarification needed ] (AUC – area under the curve – meaning, food may slow absorption, but the total amount of the chemical will be absorbed with or without food). Half-life is generally in the 10–12 hour range, subject to differences in CYP genotypes, liver function and renal function. It is metabolized in the liver, and its inactive metabolite is excreted in the urine. Urinary excretion of the unchanged drug ranges from 0% to as high as %, depending on various factors. 
One of the most controversial issues surrounding drug use and abuse is mandatory drug testing. If you’re writing an argumentative or persuasive research paper, you could examine whether certain groups of people -- such as students, student or professional athletes, employees and welfare recipients -- should be required to submit to mandatory drug testing. Whether you choose to focus on one specific group or the issue of mandatory drug testing at large, you’ll want to analyze the efficacy of such programs by presenting evidence that allows you to support your position while refuting the other side of the argument.