<unk> (injection) is an analgesic that is FDA approved for the treatment of moderate to severe pain and for preoperative medication, support of anesthesia and obstetrical analgesia.   Common adverse reactions include lightheadedness, dizziness, sedation, nausea, vomiting, headache, agitation and tremor.
Meperidine 
Esketamine
Fentanyl 
Ketamine
Nalorphine
Remifentanil
Codeine
Aceclidine