Probable neuropsychiatric toxicity induced by dihydrocodeine in a peritoneal dialysis patient: a case report and literature review

Dihydrocodeine is metabolized by the liver and subsequently excreted by the kidneys following oral administration. Consequently, individuals with renal impairment are susceptible to drug buildup, heightening the likelihood of harmful effects, including central nervous system depression and reversible delirium. A 70-year-old male patient undergoing maintenance peritoneal dialysis fell into a coma one week after taking acetaminophen and Dihydrocodeine Tartrate (a compound preparation of acetaminophen and dihydrocodeine, called Lu Gai Ke). This compound formulation contained 500 mg of acetaminophen and 10 mg of dihydrocodeine. We conducted additional laboratory tests and imaging studies for this patient. The preliminary diagnosis is metabolic encephalopathy caused by an overdose of dihydrocodeine. Following an 8-hour automated peritoneal dialysis (APD) session, the patient experienced a brief period of lucidity. The patient ultimately achieved complete neurological recovery following treatment with naloxone (administered intermittently) and supportive dialysis. This case demonstrates that automated peritoneal dialysis can partially clear the metabolites of dihydrocodeine from the bodies of patients undergoing maintenance peritoneal dialysis. However, specific antidotes remain the primary measure for treating opioid poisoning. Codeine-like opioids are best avoided in end-stage renal disease; safer analgesics and prompt naloxone availability are strongly recommended.