Efficacy and safety of oral ketamine for the relief of intractable chronic pain: A retrospective 5-year study of 51 patients.

Background: This work summarizes the efficiency, failures and adverse effects of oral administration of ketamine at home for intractable pain.

Methods: This 5-year retrospective study involved testing ketamine by intravenous in-hospital administration, then a conversion to an oral route, or oral treatment directly administered at home. The daily intravenous dose was increased by steps of 0.