Patents are 20 years. You should bring yourself up to speed.
http://www.fda.gov/Drugs/DevelopmentApprovalProcess/ucm079031.htm#How many years is a patent granted for?
Nope. Drug patents are thirty years thanks to Bush. They can be renewed for another ten years after the first term expires. And you’ve begged the question once again. How long *should* they be and how do you know? You said limited patents were good. How do you what the limit should be?