It depends on your liver and kidneys since they are the major metabolizers of narcotics. For hydrocodone, it usually takes 4 to 8 hours.

 Vicodin is a pain killer which is also an opiate, and could cause damage to the liver if used in high doses over a long period of time. It can also prove to become very addictive if used extensively, and those taking vicodin on a regular basis may experience withdrawal symptoms like lack of sleep, uneasiness etc.

The dosage of vicodin totally depends on individual factors like weight, age and also what other medication is currently being consumed by the patient.

Vicodin, if taken on a regular basis, can be detected in the urine for a considerably long period of time. Generally a drug screen is used for employment purposes and vicodin showing up in the drug screen depends on factors like what kind of drug screen is used etc. Usually the drug stays in the system for around 24 to 36 hours, although one should stop taking in five days in advance to be completely sure.