Celexa and luvox (fluvoxamine) were both available in europe in the 1980's before prozac came on the market in'89 yet were not available in u.s. til the 90's-why?

This is usual: Many medications are studied and used in europe before becoming available in the us. Each country has its own version of the fda (food and drug administration) in the us, and their criteria for safety and effectiveness differ. Before a medication can be marketed in the us, it must pass fda standards for studies. Developing ; doing studies that meet fda criteria takes more time.