Name one common over-the-counter (OTC) medication used for pain relief.

Acetaminophen is widely recognized as a common over-the-counter medication used for pain relief. It is effective in alleviating mild to moderate pain, such as headaches, muscle aches, and osteoarthritis pain. As a non-opioid analgesic, acetaminophen works by inhibiting the production of certain chemicals in the brain that signal pain and discomfort, making it a popular choice among consumers seeking relief without the need for stronger prescription medications.

In contrast, while aspirin also serves as a pain reliever, it is less commonly recommended for certain populations due to potential side effects, such as gastrointestinal bleeding. Antihistamines, typically used to manage allergies, do not provide pain relief. Cough syrup is formulated for treating cough and related symptoms, thus not serving the specific purpose of pain management. This makes acetaminophen the most appropriate choice in the context of over-the-counter pain medications.