The analgesic efficacy, tolerability, safety and pharmacokinetics of a sublingual wafer formulation of ketamine in burns patients undergoing painful dressing changes

The change of dressing in burns patients is a painful procedure; however, the pain is only short-lasting. Therefore pain relief requires a fast, but short acting method. Options widely used are inhalation of Entonox (a pain relieving gas mixture), short acting morphine-like tablets or administration of morphine-like drugs by patient-controlled analgesia pumps. In Royal Perth Hospital ketamine, a short-acting pain killer has been used successfully via patient controlled analgesia pumps for many years and, since the Bali disaster, by use of administration under the tongue (as liquid or lozenge made by hospital pharmacy). A new preparation of ketamine as a wafer, to be administered under the tongue, has been shown to have a rapid onset of effect with minimal adverse effects in volunteers. This could be a promising way to provide pain relief for dressing changes without the need for an intravenous line and with minimal adverse effects. The new medication will be tried in in-patients of the burns unit requiring painful dressing changes. The medication will be compared to placebo wafers, but patients can at any time ask for rescue analgesia, which will include the methods mentioned above. It is expected that ketamine wafers provide better analgesia than placebo with less need for rescue analgesia than placebo. The results of this trial will permit further development of this promising new form of pain relief.