what is a prodrug

A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized into a pharmacologically active drug. Prodrugs are designed to improve how the drug is administered, absorbed, distributed, metabolized, and excreted in the body. They can be used to improve bioavailability when a drug itself is poorly absorbed from the gastrointestinal tract, or to improve how selectively the drug interacts with cells or processes that are not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. Prodrugs can be viewed as drugs containing specialized nontoxic protective groups used in a transient manner to alter or to eliminate undesirable properties in the parent molecule. Approximately 10% of all marketed drugs worldwide can be considered prodrugs, and since 2008, at least 30 prodrugs have been approved by the FDA.