it actually depends on the medication. each medication has a performance limit and the times can differ. if there is a specific medication you are researching, the dose, the duration, and the treatment all very in how long a drug stays in your system. I hope that helps
A good source to use for medication metabolism is Epocrates.com. Visit the site, look up the particular medication you are looking for (all of them have different excretion rates) and it will tell you everything you need to know.
It depends on your metabolism, how long you've been taking them, how strong they are, what kind, etc, but all in all an average of 3-5 days