Talwin is a brand name for the opioid pain medication pentazocine. There are several synonyms for talwin that refer to the same drug, including pentazocine hydrochloride, Talwin NX, Fortral, and Talacen. These synonyms may be used interchangeably in medical contexts to describe pentazocine or medications containing pentazocine. Pentazocine is a powerful pain reliever that is prescribed for moderate to severe pain, typically after surgery or injury. While it can be highly effective, it also carries significant risks of addiction and overdose and should only be used under close medical supervision.