<prompt> Tramadol isAntiflatulentAntireflux drugBeta-blockerOpioid analgesic  <response>: Ans. d Opioid analgesic. Ref. KD Tripathi, Pharmacology6th. 453 Tramadol is synthetic centrally acting opioid analgesic having modest affinity for ji receptors. Unlike other opioids, it inhibits reuptake of NA and 5-HT and thus activates monoaminergic spinal inhibition of pain. Its oral bioavailability is good and it has minimal hemodynamic effects and hence safer in patients with compromised CVS function. It is indicated for medium intensity short lasting pain due to diagnostic procedures, injury, surgery, etc as well as for chronic cancer pain. 