It's true that different therapies, pharmaceutical and otherwise, may have different rates of effectiveness. A science-based approach would see a doctor consider the potential effectiveness vs the potential risks and assign the most likely successful intervention.  The condition would then be monitored and the course of therapy altered if the desired outcomes were not being achieved in an adequate amount of time. No treatment is 100% effective or safe for everyone. But forgoing a treatment because it might not work or may have some risk, for a condition that has higher risk, is like refusing a life buoy to be thrown to you when you are in danger of drowning because there's a small chance it may hit you on the head and knock you out.