Respiratory depression may occur (increased risk in elderly, debilitated patients, those suffering from conditions accompanied by hypoxia, hypercapnia, or upper airway obstruction). Additive CNS-depressive effects when used in conjunction with alcohol, other opioids, or illicit drugs. Elevation of intracranial pressure (should not be used in patients who may be susceptible to the effects of raised cerebrospinal fluid pressure such as those with evidence of head injury and increased intracranial pressure). Abuse potential may occur (monitor patients closely for signs of abuse and addiction). Impaired mental/physical abilities. Seizures have been observed. Potentially life-threatening condition could result from concomitant serotonergic administration (serotonin syndrome). Like other drugs with µ-opioid agonist activity, may cause spasm of the sphincter of Oddi and should be used with caution in patients with biliary tract disease, including acute pancreatitis. Withdrawal symptoms may occur if tapentadol is discontinued abruptly.