Background: Tramadol is an adulterant of illicit opioids. As it is a serotonin-norepinephrine reuptake inhibitor as well as a μ-opioid agonist, tramadol adulteration may worsen overdose signs and symptoms or affect the amount of naloxone patients receive.
Methods: This is a multicenter, prospective cohort of adult patients with suspected opioid overdoses who presented to one of eight United States emergency departments and were included in the Toxicology Investigators Consortium's Fentalog Study.