The drug Prozac is a very powerful anti-depressant. So, it is amazing to discover that the medication that is supposed to help control mental illness is also responsible for increased thoughts of suicide. The problem is even more profound in younger children and teenagers, but adults can experience these adverse side effects as well. The drug can also negatively interact with other prescription and over the counter medications. So, you need to tell your doctor everything that you take, even if it is not on a daily basis. The drug Prozac can also cause dangerous side effects, if you quit taking your daily dose. If you want off of Prozac, you doctor will have to wean you off of the drug.