Acetyldihydrocodeine is an opiate

Opiate

In medicine, the term opiate describes any of the narcotic opioid alkaloids found as natural products in the opium poppy plant.-Overview:Opiates are so named because they are constituents or derivatives of constituents found in opium, which is processed from the latex sap of the opium poppy,...

 derivative discovered in Germany in 1914 and was used as as a cough suppressant and analgesic

Analgesic

An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....

. It is not commonly used, but has activity similar to other opiates. Acetyldihydrocodeine can be described as the 6-acetyl derivative of dihydrocodeine

Dihydrocodeine

Dihydrocodeine, also called DHC, Drocode, Paracodeine and Parzone and known by the brand names of Synalgos DC, Panlor DC, Panlor SS, Contugesic, New Bron Solution-ACE, Huscode, Drocode, Paracodin, Codidol, Didor Continus, Dicogesic, Codhydrine, Dekacodin, DH-Codeine,...

 and is metabolised in the liver by demethylation and deacetylation to produce dihydromorphine

Dihydromorphine

Dihydromorphine is a semi-synthetic opioid invented in Germany in 1900. In structure, it is very similar to morphine, the only difference being the reduction of the double bond between positions 7 and 8 in morphine to a single bond...

.

Since acetyldihydrocodeine has higher lipophilicity than codeine

Codeine

Codeine or 3-methylmorphine is an opiate used for its analgesic, antitussive, and antidiarrheal properties...

 and is converted into dihydromorphine rather than morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

, it can be expected to be more potent and longer lasting, and also have higher bioavailability

Bioavailability

In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...

 than codeine.