No single rate of administration or composition of maintenance intravenous fluids is appropriate in all circumstances. Thus, intravenous fluids may be viewed as medications that require careful dose adjustment that is specific to the disease state of each patient.
Codeine - 1 day in urine, up to 90 days in hair, 12 hours in blood. Fentanyl - 1 day in urine, up to 90 days in hair, 4 hours in blood. Morphine - 2 -3 days in urine, up to 90 in hair, 6 - 8 hours in blood. Heroin - 3 to 4 days in urine, up to 90 in hair, up to 12 hours in blood.
It has a half life of 4 to 8 hours, which means that about 4 to 8 hours after you take it, only half of the dose is left in your system. Depending on how your body metabolizes this drug, it is typically gone from your system in one to two days.