Demerol, also known by its generic name meperidine, is a prescription opioid pain medication used to relieve moderate to severe pain. It works by affecting certain chemicals in the brain and nervous system to reduce the perception of pain.

Like other opioids, Demerol carries the risk of dependence, addiction, and overdose if not used as prescribed. It's important to take Demerol exactly as directed by a healthcare provider and to avoid increasing the dosage or frequency without their guidance.

Common side effects of Demerol include dizziness, drowsiness, constipation, nausea, and vomiting. Serious side effects such as slowed or shallow breathing, confusion, and low blood pressure may occur, especially at higher doses or when combined with other medications.