Also Known As: Dihydrocodeine, Drocode, Paracodeine, Parzone, Synalgos DC, Panlor, Contugesic, Huscode, Codidol, Paracodin, Dicogesic, Codhydrine, DH-Codeine
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, Didrate, Dihydrin, Hydrocodin, Nadeine, Novicodin, Rapacodin, Fortuss, Remedeine, Dico, and DF-118 amongst others (e.g. Paramol), is a semi-synthetic opioid analgesic developed in Germany in 1908 and put on the market in 1911. It is prescribed for pain, severe dyspnea, or as an antitussive, either alone or compounded with aspirin or paracetamol, as in co-dydramol. In some countries, controlled-release dihydrocodeine and/or the immediate release forumulations are used as an alternative to methadone in treatment of opioid dependency and addiction.
Commonly available as tablets, solutions, elixirs, and other oral forms, dihydrocodeine is also available in some countries as an injectable solution for deep subcutaneous and intra-muscular administration. As with codeine, intravenous administration should be avoided, as it could result in anaphylaxis and dangerous pulmonary edema. In past times, dihydrocodeine suppositories were used; however, dihydrocodeine is available in suppository form on prescription.
Dihydrocodeine is used as an alternative or adjunct to codeine for the aforementioned indications. It is available as the following salts, in rough descending order of frequency of use: bitartrate, phosphate, hydrochloride, tartrate, hydroiodide, methyliodide, hydrobromide, and sulfate. The salt to free base conversion factors are 0.67 for the bitartrate, 0.73 for the phosphate, and 0.89 for the hydrochloride.
Dihydrocodeine was developed during the intense international search for more effective antitussives, especially to help reduce the airborne spread of tuberculosis, pertussis, pneumonia, and similar diseases, in the years from c.a. 1895 to 1915, and is similar in chemical structure to codeine. Depending on individual metabolism, dihydrocodeine is 100 to 150 percent as strong as codeine. Although dihydrocodeine does have extremely active metabolites, in the form of dihydromorphine and dihydromorphine-6-glucuronide (one hundred times more potent), these metabolites are produced in such small amount that they do not have clinically important effects.