I believe that the wave of the future will be to characterize drugs with respect to which segment of the population they are most likely to help.
For example, it has been known for a long time that the drug metabolizing enzymes in the liver have many different genetic variants which drastically affect how efficiently they eliminate drugs (and other substances) from the blood. Obviously, someone with more efficient enzymes might need a higher dose than someone whose enzymes take twice as long to eliminate the drug. It’s about time for drug prescribing practice to catch up with what is known in the field of genetics.