Yeah, six months is way to long. By then any drug, short or fast acting, should be in your system and doing something for you.

Four to six weeks is usually a good amount of time before making a decision.

I couldn't agree more- do not go cold turkey on medication unless there is a side effect that causes pain or distress. Check online for what side effects to watch out for (the serious ones) and only stop a drug in those instances, or any time you are not feeling healthy.
Also, do call your doctor in those cases- leave a message if they cannot answer right away, and if you feel that it is necessary, go see a GP, as they are usually pretty accessible.