"Burst" ketamine for refractory cancer pain: an open-label audit of 39 patients.
The results of a novel approach to the use of ketamine in refractory cancer pain are reported. In this prospective, multicenter, unblinded, open-label audit, 39 patients (with a total of 43 pains) received a short duration (3 to 5 days) ketamine infusion. The initial dose of 100 mg/24 hr was escalated if required to 300 mg/24 hr and then to a maximum dose of 500 mg/24hr. The overall response rate was 29/43 (67%). Analysis of results according to pain mechanisms showed that 15/17 somatic and 14/23 neuropathic pains responded. In 5 patients who appeared to respond, it is possible that another concurrent intervention may have contributed in whole or part for the pain relief observed. After cessation of ketamine, 24/29 maintained good pain control, with a maximum documented duration of eight weeks. However, 5 of the initial 29 responders experienced a recurrence of pain within 24 hours, and ketamine was recommenced. Of these, 2 underwent another intervention for pain control while 3 continued on ketamine until their deaths between two and four weeks later. Twelve patients reported adverse psychomimetic effects, with the incidence rising with increasing dose. Four of these were non-responders and the ketamine was stopped. Eight were responders, and in 3 the adverse effects were rendered acceptable with dose reduction; the other 5 rejected a dose reduction. The results reported suggest the need for further investigation of the place of ketamine in cancer pain management.
Jackson
K
K
McCulloch House, Monash Medical Center, Clayton, Victoria, Australia.
Ashby
M
M
Martin
P
P
Pisasale
M
M
Brumley
D
D
Hayes
B
B
D000328:Adult; D000368:Aged; D000700:Analgesics / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000188:drug therapy*; D010148:Intractable Pain / Q000188:drug therapy* / Q000209:etiology*; D011446:Prospective Studies; D013997:Time Factors
D000700:Analgesics; D007649:Ketamine