Which of the following compounds is typically used as an analgesic?

Meperidine is an opioid analgesic that is primarily used to treat moderate to severe pain. It works by acting on the central nervous system to alter the perception of pain and increase pain tolerance. This makes it effective in various clinical situations, including post-operative pain management and labor pain relief. The appropriate use of meperidine can provide significant comfort to patients experiencing pain during medical procedures, particularly in settings like radiology where patients may be undergoing invasive or uncomfortable imaging techniques.

Other compounds listed have different primary uses. Penicillin is an antibiotic used to treat bacterial infections, heparin is an anticoagulant used to prevent blood clots, and lidocaine is primarily a local anesthetic also utilized for its antiarrhythmic properties. While lidocaine can provide temporary pain relief in a specific area, meperidine is unique among the options for its broad analgesic properties in treating pain.