Depends on drugs. General anesthesia isn't just one medication--it's a combination. Some induce sleep, some (like the anesthesia gases) maintain sleep, some relax muscles, some relieve pain, etc. Each is metabolized at a different rate. In general, you can expect them to vanish within 6-8 hours, but it will take longer if the kidneys or liver don't work well. Don't drive within 24 hours of having anesthesia.
3 days. Modern anesthetics are essentially removed from the body completely within 72 hours. The most common cause of symptoms after this period are the postoperative narcotics that a patient takes to control pain. I hope that this answers your question.