[Ketamine use in outpatients: What can we learn from current practices?]

Two off-label use of ketamine are framed by recommendations: in intractable pain in palliative situations or in postoperative pain. Ketamine is used in hospital but can also be used outside hospital with dispensations by hospital pharmacy to outpatients. Few data are available on ketamine use outside hospital. In this context, the French Addictovigilance Network has set up a study with hospital pharmacies.

This survey assesses ketamine dispensations from 1 January to 30 April 2019, for patients who have an administration of ketamine outside hospital.

Sixty-five (65) hospital pharmacies have dispensed ketamine for 553 patients. Ketamine was indicated within non-palliative care in 86% of cases. Most of non-cancer pain were in fibromyalgia (44%) and neuropathic pain (29%). During the 4-month monitoring period, 1352 dispensations were analysed. The frequency of administration is daily in 91% of cases within palliative care whereas it is much more diverse within non-palliative care (33% daily, more than 15 different frequency in fibromyalgia). Within palliative care, ketamine is most administered intravenously or by Patient Controlled Analgesia or syringe pump (78% of cases) whereas in non-palliative care, ketamine is most used subcutaneously (44%), orally (32%) or both subcutaneously and orally (20%). A large number of ampoules could be dispensed (more than 30 ampoules for 10% of dispensations).

These data highlighted that recommendation in pain are not respected because most of ketamine is used within non-palliative care context and it should be noted a great heterogeneity of practice. This study underlines the urgency of targeted and clear information on certain off-label uses of ketamine for which no robust clinical studies are available and for which the risk of health complications like psychiatric (addiction), urologic and hepatologic complications is proven.