Althesin (alphadione, CT 1341) a 'new' induction agent for anesthesia

Althesin (alphadione) is a hypnotic agent introduced in the U.K. a few years ago by the firm of Glaxo. It is mixture of two steroids: alphaxalone 9 mg per ml and alphadolone 3 mg per ml, in solution in cremophore EL. After a concise review of the history of steroid anesthetics, the pharmacology of the new product is described. In a personal investigation, Althesin was used to induce anesthesia in 100 patients. The dose equivalent with thiopentone was determined first. It was found to amount to 52 microliter per kg corresponding to 3 mg per kg of thiopentone. A separate form was completed for each individual patient, to record the side effects, if any. The pulse and blood pressure were checked once a minute after the induction (for 5 minutes). In 8 patients the following parameters were recorded: plethysmogram, ECG, central venous pressure, pulse rhythm arterial pressure, stroke volume and cardiac output. Compared with thiopentone, Althesin is not significantly worse, but neither does it present any advantages where the circulatory parameters determined are concerned. In view of this and the recent publication concerning hypersensitivity reactions, we have ceased to use this hypnotic agent in our department.