Canadian researchers are warning against giving kids codeine after surgery to remove their tonsils, after a two-year-old boy died following the routine operation.
The boy had had a tonsillectomy to help treat his snoring and sleep apnea. He had the fairly simple surgery at an outpatient clinic, and went home that day.
To manage his pain, the boy's mother gave her son a prescribed syrup of codeine and acetaminophen, exactly as directed. On the second night after surgery, the boy developed a fever and wheezing. The next morning, he was found dead.
Blood tests later revealed the boy had fatally high levels of morphine, a related opiate that's several times stronger. That's when the coroner asked Dr. Gideon Koren and his team of researchers to look at the case.
Koren, who is the director of the Motherisk program at the Hospital for Sick Children in Toronto, also studies molecular toxicology at the University of Western Ontario. He discovered that the child had a rare genetic anomaly that made him an "ultrarapid metabolizer" of codeine.
In most people, their livers convert about 10 to 15 per cent of codeine into morphine. Ultrarapid metabolizers convert about 50 per cent. In this case, all that extra morphine depressed the boy's breathing as he slept, which probably caused his death.
UWO pharmacology researcher Catherine Ciszkowski, who also worked on the investigation, says kids have experienced respiratory depression with morphine levels over 20 nanograms per milliliter; this boy had 32 ng per milliliter.
Two years ago, Koren raised the alarm about the dangers of giving codeine to breastfeeding mothers, after investigating the case of a 13-day-old infant who died from morphine overdose.
He found that, like the boy in this case, the infant's mother was an ultrarapid metabolizer of the codeine that had been prescribed her following an episiotomy. The morphine travelled into her breast milk and proved fatal to her breastfed baby.
It's estimated just over one per cent of Caucasians carry the genotype that makes them ultrarapid metabolizers, but the incidence is higher among those of Mediterranean descent and could be as high as 30 per cent in those of African origin.
"They can be totally healthy all their lives until the minute they take the codeine," Koren tells Â鶹´«Ã½.
He says it's possible other children with his genetic anomaly have died in similar ways, but this is the first case to be documented.
Doctors and parents need to be aware of this codeine risk, Koren says, especially since tonsillectomies are growing in popularity as a treatment for childhood sleep apnea.
There is a test to identify ultrarapid metabolizers, but it's not yet commonly available. In the meantime, Koren suggests doctors using codeine in children consider lower doses, asking parents to carefully monitor for breathing problems.
Or, better yet, he'd like doctors to stop using codeine altogether in kids undergoing tonsillectomies. He says in Europe, doctors tend to prescribe ibuprofen or other drugs called non-steroidal anti-inflammatory drugs that do not depress breathing.
He says studies are ongoing that might provide more information on which pain relievers are best for children.
Koren also notes that a tonsillectomy is not always effective in treating sleep apnea, a condition that already compromises breathing during sleep. "If the apnea doesn't go away, codeine will also suppress the child's breathing," he says.
He says children really should be kept in hospital under surveillance for at least 24 hours after tonsil surgery, to both monitor their breathing and to see if the apnea persists.
With reports from CTV medical specialist Avis Favaro and CTV Toronto's Monica Matys
