So the FDA doesn't care about the effectiveness of Drugs they approve, whats up with that?
The FDA cares a lot. Once a drug is approved, the FDA does not stop monitoring its safety and efficacy. The pharmaceutical companies are required to continue to work with the FDA in what is called a "phase 4 clinical trial," which is where the company still collects data on patients who are using the approved drug by prescription.
If the company wants to market the drug for a slightly different purpose than it was approved for, the company has to do clinical trials in support of the altered use. For example, the approved implant delivers 8 mg of the drug per day. But if the company wants to market an implant with a different dose, they have to test at that dose before the FDA approves it.
Drug testing and approval is a very complicated business, involving scientists, physicians, lawyers, and reams of paperwork.