A peripheral opioid antagonist for treating urinary retention induced by opioids: A case report

A peripherally acting μ-opioid receptor antagonist for treating opioid-associated tinnitus: A case report

BACKGROUND

The use of opioids occasionally causes tinnitus. However, there is a paucity of data regarding the use of peripherally acting μ-opioid receptor antagonists for opioid-associated tinnitus in patients with cancer.

ACTUAL CASE

A 74-year-old male with pancreatic cancer complained of abdominal pain. Two days after initiating oxycodone therapy, the patient experienced tinnitus during body movements. Although peripheral tinnitus disappeared after discontinuing oxycodone, it reappeared with hydromorphone or tapentadol administration.

POSSIBLE COURSES OF ACTION

Drug cessation is a preferred intervention for drug-induced tinnitus; however, the cessation of opioids may not be feasible in patients with cancer who are already taking opioids.

FORMULATION OF A PLAN

Based on the presumed mechanism of peripheral tinnitus, the use of peripherally acting μ-opioid receptor antagonists was planned, and 200 μg/day of naldemedine was prescribed for tinnitus relief.

OUTCOME

Tinnitus disappeared immediately after initiating naldemedine, and the pain was well-controlled. The effect was preserved after increasing or switching opioids.

LESSONS

The use of peripherally acting μ-opioid receptor antagonists may be an option to treat opioid-associated tinnitus without compromising the analgesic effects.

VIEW

Further clinical data regarding the secondary effect of peripherally acting μ-opioid receptor antagonists on opioid-associated complications other than constipation are required.

Effects and Limitations of Naldemedine for Opioid-Induced Urinary Retention: A Case Report

A 78-year-old man with postoperative recurrence of esophageal cancer was admitted to the hospital due to chest pain and dyspnea. Oral short-acting opioids provided some relief, but chest pain persisted and worsened, leading to the initiation of a transdermal fentanyl patch. However, the patient developed opioid-induced urinary retention, which was treated with a naldemedine, a medication used for opioid-induced constipation and urinary retention. Opioid switching led to recurrent urinary retention, requiring placement of a urinary catheter. The patient ultimately required continuous deep sedation for refractory symptoms and died several days later.