How long does it take for drugs to leave my body and for me to be safe to drive?
This is a dangerous question. Everybody metabolises at a different rate and different drugs are metabolised/excreted from your system at different rates. Some of the tests for drug driving are based on their still being a metabolised form of the drug in your system, rather than the primary drug itself.
It’s never going to be safe for you to assume that you won’t have the drug in your system if you leave it for X number of days/hours before you drive as there is clearly no set rule and it will always depend on you as an individual, the rate at which you metabolise, the type of drug that you take, the purity of the specific drug in question etc.