The loading dose of a medication is a higher than normal dose given when a patient starts taking a new drug. After the loading dose, the patient drops down to a lower maintenance dose.
Loading doses are generally used for medications that are removed from the body slowly. The higher dose given initially quickly raises the level of the drug in the patient's body to the desired therapeutic level, and this level can then be maintained by a lower everyday dose. This method is ideal for patients that need to benefit from a medication quickly or for medication that would otherwise take a long time to reach therapeutic levels.