What is Pharmacokinetics (PK)? 295 PK is the description of the time course of a drug in the body,encompassing absorption,distribution, metabolism, and excretion (ADME) o What the body does to the drug? 2What is Pharmacokinetics (PK) ? PK is the description of the time course of a drug in the body, encompassing absorption, distribution, metabolism, and excretion (ADME). 2 What the body does to the drug?