A healthy 14-year-old Irish girl experienced confusion and loss of the ability to create new memories after prolonged consumption of a codeine-containing over-the-counter (OTC) cough medicine, in the first reported case of its kind.
Writing in BMJ Case Reports, the authors from the NUI Galway and Letterkenny General Hospital said the girl experienced flu-like symptoms and took two-to-three spoonfuls of a codeine cough suppressant daily over a 15-day period.
She did not exceed the recommended daily dose of three-to-six spoonfuls but she did exceed the maximum recommended duration of usage of three days. Each spoonful is equivalent to 15mg of codeine, so the patient consumed a total of 450-675mg over 15 days, instead of the recommended maximum dosage of 270mg over three days.
The girl falsely reported having completed tasks, such as claiming she showered when it was obvious to her mother she had not. She also switched languages while completing her homework. She slept for up to 20 hours a day, had a decreased attention span and suffered from intermittent headaches.
A urine test was positive for codeine and no other drugs were present in her system.
The authors, led by final-year medical student David O’Reilly of the School of Medicine at NUI Galway and the Donegal Clinical Research Academy at Letterkenny General Hospital, warned the risks associated with codeine usage “may be particularly unnecessary” with OTC cough suppressants because evidence of their efficacy was absent.
“The usage of codeine in the paediatric setting has been highlighted in recent years with many reported deaths — mostly due to respiratory depression. The combination of lack of efficacy, risk of acute intoxication and dependence, suggests that the use of OTC codeine preparations may be unwarranted,” they said.
Symptoms of codeine toxicity usually include central nervous system depression, respiratory depression, severe itching of the skin and flushing.
BMJ Case Reports 2015; online Dec 23, doi:10.1136/bcr-2015-212727.