I am in pharmacology at a community college. I had other science courses, but am a little hazy on this subject. My study guide states….explain how the effectiveness of a drug is based on distribution. Then it lists 3 different types which are protein binding, distr. to CNS (blood-brain barrier), and mother to fetus. My book does not really give a simple explanation of these processes that I can understand. I thought my comprehension was sufficient until I opened up this book. I did get a 3.5 in Eng 111. Can someone help in this area? I will probably be frequenting this web site several more times as I have nursing school after pharm.
So what protein binding is is the proportion of the drug that is bound to protein in plasma (most of which is albumin). The protein-bound fraction is inactive and will not be excreted and because of this reason the efficacy and half-life of a drug may vary with its protein binding. Other drugs may also affect another drugs protein binding by displacing it from albumin thereby acutely enhancing a drug’s effect due to higher plasma levels (well-known drug interaction most often seen on pharmacology tests!). Protein binding influences the volume of distribution of a drug.