Probable codeine phosphate-induced seizures.
OBJECTIVE
To report a case of seizure activity associated with oral codeine phosphate administered for analgesia in an elderly woman with end-stage renal disease.


METHODS
A 73-year-old Taiwanese woman with end-stage renal disease received oral codeine phosphate 30 mg 4 times daily for her back and rib pain without adjustment of her dosage regimen. Seven days after starting codeine therapy, the woman became stuporous and developed tonic-clonic seizures. After phenytoin initiation, codeine discontinuation, and naloxone administration, the seizures did not recur.


CONCLUSIONS
Codeine is a frequently used opioid analgesic, especially when pain control with acetaminophen or nonsteroidal antiinflammatory drugs fails. Although seizures associated with codeine have been reported, pertinent data are very limited and the exact mechanism is unknown. An objective causality assessment indicated the seizure to be a probable drug-related event in this patient.


CONCLUSIONS
Elderly patients with end-stage renal disease may be predisposed to seizures with higher doses of codeine phosphate. It is imperative to adjust the codeine dosage regimen based on patients' renal function to avoid the potential toxicity with overdose.
Kuo
Shih-Chen
SC
Institute of Clinical Pharmacy, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Lin
Ya-Chu
YC
Kao
Shu-Min
SM
Yang
Yea-Huei Kao
YH
D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects*; D000927:Anticonvulsants / Q000627:therapeutic use; D003061:Codeine / Q000009:adverse effects*; D005260:Female; D006801:Humans; D010672:Phenytoin / Q000627:therapeutic use; D012640:Seizures / Q000139:chemically induced* / Q000188:drug therapy
D000701:Analgesics, Opioid; D000927:Anticonvulsants; D010672:Phenytoin; D003061:Codeine