As part of this new study, researchers analyzed all kratom exposures reported to the country's poison centers between 2011 and 2017, totaling more than 1,800 exposures. Most cases occurred in adults over 20, but 137 in adolescents and 48 in children under 12, including seven neonates, suggesting that kratom crosses the placenta during pregnancy. One of the newborn's shows is produced by breast milk.
Henry Spiller, co-author of the study and director of the Central Ohio Poison Center at Nationwide Children's Hospital, said his center had seen an increasing number of phone calls coming from from hospitals, asking how to better manage kratom exposures.
"We have just started to see cases, very serious cases," said Spiller.
The effects of the study varied: rapid heartbeat, agitation and high blood pressure, seizures, coma, renal failure and death. Eleven deaths related to kratom exposure, either by itself, or in combination with other substances, during the study period.
In addition, five of seven exposed neonates exhibited withdrawal symptoms.
"People who choose to use kratom should be aware of the potential risks.This is not because it is currently classified as a herbal supplement that it is regulated or that it is regulated. It's safe, "Spiller said in a statement.
Kratom acts on the same brain receptors as morphine and other opioids, but the action itself may differ from traditional opioids such as heroin and oxycodone.
"If you look at the effects, it's not really the expected opioid effects," Spiller said. "We are seeing convulsions, tachycardia [rapid heartbeat], hypertension, agitation. If it was an opioid, one could expect a respiratory depression "or a slow breathing.
Researchers have asked the FDA to regulate kratom in order to ensure consistency in the quality, purity and concentration of the product available to consumers.
CNN's Nadia Kounang contributed to this report.