By Rob Goodier

NEW YORK (Reuters Health) - Morphine after a tonsillectomy may exacerbate breathing problems in kids with obstructive sleep apnea, but ibuprofen appears to be just as effective without the respiratory side effects, according to findings published online January 26 in Pediatrics.

"This means that (morphine) should not be given at home, where monitoring of respiratory status is far from optimal. In a hospital setting, under appropriate care, it may be used cautiously," said study leader Dr. Gideon Koren, director of the Motherisk Program and Senior Scientist at The Hospital for Sick Children of the University of Toronto, in email to Reuters Health.

Dr. Koren and colleagues compared painkillers in a group of 91 kids who were discharged after surgery and randomized to either 0.2-0.5 mg/kg of oral morphine plus 10-15 mg/kg acetaminophen every four hours or 10 mg/kg of ibuprofen every six hours plus 10-15 mg/kg of acetaminophen every four hours. Their parents measured blood oxygen saturation and recorded the kids' pain levels according to both the Objective Pain Scale and Faces Scale on the first and fifth days after surgery.

On the first night, oxygen desaturation improved in 68% of the kids on ibuprofen, but in only 14% of those on morphine. In terms of efficacy, the kids rated the analgesic effects of both drugs as more or less equal.

"Studies have shown that up to 25% of these children do not reverse their sleep apnea immediately after surgery. Giving narcotic analgesics, which are known to decrease respiratory drive, is therefore problematic," Dr. Koren said.

Rates of tonsillar bleeding were similar (three kids on ibuprofen and two on morphine). Other adverse reaction rates were similar as well.

Until recently, codeine was prescribed for post-tonsillectomy and adenoidectomy pain. But in 2012 the U.S. Food and Drug Administration issued a statement contraindicating codeine for these patients because it was linked in rare cases to respiratory failure and death.

The results of this study should change clinical practice, said Dr. Reginald Baugh, Chief of Otolaryngology at the University of Toledo College of Medicine and Life Sciences in Ohio, in email to Reuters Health.

"This study provides evidence that the use of narcotics post-tonsillectomy may lead to greater safety concerns than the use of non-narcotics," said Dr. Baugh, who was not involved in the study.

In fact, there is little reason to assume that the safety profile for morphine in kids post-tonsillectomy would be different after any surgery, Dr. Baugh said.

That said, there were some limitations to this research, according to Dr. Baugh. The researchers might have better measured breathing by monitoring for hypercarbia rather than oxygen desaturation. And the study may not have accounted for non-compliance of the parents who administered the analgesics. Results may have been skewed by parents who withheld morphine for fear of hurting their children, or who gave too much out of concern for children with post-surgical pain, Dr. Baugh said.

These results may point to a broader issue in drug approval, Dr. Koren said.

"Most drugs used in children have not been approved by the FDA and Health Canada. This study highlights the urgent need to study medications in children and not to extrapolate results in adults," Dr. Koren said.

SOURCE: http://bit.ly/1uRyTtM

Pediatrics 2015.