Comment: dyspnea with controlled-release morphine sulfate tablets.

Abstract

TO THE EDITOR: The case report indicating a possible link between controlled-release morphine and dyspnea (DICP 1988;22:397-9) is of interest. The patient's dyspnea mayor may not have been due to controlled-release tablets. What is most unfortunate, however, is the apparent confusion between dyspnea and respiratory depression. The case report includes a long discourse on respiratory depression and even concludes by stating"... careful consideration of its [controlled-release morphine sulfate's] possible respiratory depressant effects should be made when it is prescribed for elderly patients." In fact, there is absolutely no evidence of respiratory depression in this case. The patient's blood gases exhibited an acute respiratory alkalosis secondary to hyperventilation, precisely the opposite of respiratory depression. Furthermore, it is most unfortunate that the author chose to have a long discussion about respiratory depression without noting the extreme rarity of the adverse reaction when morphine is properly titrated in patients with pain. It has been well documented that pain is a powerful antidote to respiratory depression. 1.2 As long as morphine is properly titrated, this adverse reaction is exceedingly rare. This case is not an illustration of this adverse phenomenon. FRANKK. SIEMSEN,B.S. Pharm. DON R. PASLEY, B.S.Pharm. Staff Pharmacists Department ofPharmacy Oregon Health Sciences University Portland, Oregon 97201