analgesic adjuvant analgesic adjuvant an analgesic adjuvant is a medication that is typically used for indications other than pain control but provides control of pain in some painful diseases. for instance, caffeine has minimal analgesic effect on its own, but may have an adjuvant effect when given with paracetamol (acetaminophen). examples include: anticonvulsants carbamazepine, gabapentin, pregabalin antidepressants amitriptyline, duloxetine, venlafaxine antihistamines hydroxyzine, promethazine stimulants caffeine, cocaine, dextroamphetamine, ephedrine carisoprodol cyclobenzaprine hyoscine (scopolamine) for other uses, see adjuvant. the exact mechanism of the anticonvulsants carbamazepine, gabapentin, and pregabalin is unclear, but they are used to treat neuropathic pain with differing degrees of success. antiemetics and medication to relieve constipation are two examples of non-adjuvant medication indications because these are used to treat side effects and adverse effects.