By The Associated PressScientists describe tramadol as a messy and unpredictable man-made opioid. Its potency depends on individual users’ genetics. Researchers have found that some ethnic groups tend to process tramadol as a more potent opioid, and those groups are clustered in the areas grappling with widespread addiction _ in Africa and the Middle East. Unlike most opioids, tramadol is not internationally regulated, and individual nations are now struggling to control the drug. Tramadol can be deadly, but it has not been killing as ferociously as traditional opioids. People who take too much often have seizures.

Tramadol is an odd, unpredictable opioid, scientists say