Author reply

Abstract

In the letter by Lawlor and Frank, we noticed some misunderstanding of our findings. Our data concerned only 55 patients (of 453 [12.14%]) who were treated with high and very high doses of morphine. We have not analyzed the entire cohort of 453 patients treated with morphine and in this group of patients, contrary to what was stated in the letter by Lawlor and Frank, we found the usual side effects1 of morphine with: nausea occurring in 41.8% of patients, emesis occurring in 36.3% of patients, constipation occurring in 74.6% of patients, fecal impaction occurring in 12.7% of patients, and urinary retention occurring in 1.9% of patients. Some of the patients received the morphine for purposes of sedation, and in these patients there were signs of cognitive impairment. Unfortunately, we did not assess the cognitive status of all 55 patients. With regard to adverse opioid effects and neurotoxicity in the framework of multisystem failure, renal failure included, it was never proven that the neurotoxic manifestations were due to the opioid medication and not to hyperuremia or other causes. In our opinion the physician should be aware that in these circumstances the patients would require significantly lower doses of opioid.2 It was not our intention to promote the use of high and very high doses of morphine. Our intention was to try to dispel physicians' fears of using an incorrect dose of opioid, thus resulting in unsuccessful control of pain or suffering. Lawlor and Frank were correct when they mentioned the deficiency of the retrospective study and the lack of correlation between the side effects and the temporary increase of the morphine doses. We hope that in the near future we will be able to perform a prospective study in which we will consider all the comments of Lawlor and Frank and correlate our results with parameters of quality of life. Michaela Bercovitch M.D.*, Alexander Waller M.D.*, Abraham Adunsky M.D. , * Tel HaShomer Hospice, The Chaim Sheba Medical Center, Tel HaShomer, Israel, Department of Geriatric Medicine, The Chaim Sheba Medical Center, Tel HaShomer, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel