Opioid withdrawal syndrome with severe watery diarrhea when an analgesic regimen was converted from epidural morphine to transdermal fentanyl patch-A case report

The authors describe a case of opioid withdrawal syndrome encountered when an analgesic regime was converted from epidural morphine to transdermal fentanyl patch in which the patient's chief symptom was sudden onset of severe watery diarrhea A 46-year-old woman suffering from advanced uterine cancer consulted our clinic for right groin pain and leg edema The analgesic effect of 200mg daily of oral morphine, prescribed at the previous hospital, was quite insufficient. Permanent alcohol blockade of the right lumbar sympathetic ganglia significantly reduced her leg edema but not her pain. Continuous epidural analgesia with increment dose of morphine, up to 300mg daily, was required to relieve her pain. Two months later, we converted continuous epidural analgesia with morphine to transdermal fentanyl patch therapy due to the patient's request and the potential risk of epidural abscess or bacterial meningitis.<br>On the first day of drug replacement, 30mg of fentanyl patch and the reduced dose of epidural morphine, 100mg daily, were administered. After confirming that her pain had been controlled sufficiently during the following 24 hours, epidural infusion of morphine was discontinued. A few hours later, sudden onset of abdominal discomfort followed by severe watery diarrhea appeared. 20mg of oral morphine dramatically resolved the symptoms.<br>In Japan, reports of fentanyl patch-associated opioid withdrawal syndrome has been very rare, however, it will likely become more frequent because the potent and prolonged analgesic effect and the ease of administration of fentanyl patch will soon increase its clinical use both as a primary and a replacement analgesic. When using a fentanyl patch as a replacement analgesic, meticulous observation of a patient and early diagnosis following prompt and proper treatment of withdrawal symptom is required.