Dihydrocodeine, also called DHC or DF-118, is a synthetic opioid analgesic prescribed for postoperative pain, severe dyspnea, or as an antitussive. It was developed in the early 1900s, and is similar in chemical structure, pharmacological activity, and potency as codeine. Although dihydrocodeine does have extremely active metabolites, in the form of dihydromorphine and dihydromorphine-6-glucuronide (100x more potent), these metabolites are produced in such small amount that they do not have clinically important effects.