Which of the following is a common example of an analgesic?

Ibuprofen is a common example of an analgesic because it is widely used to relieve pain and reduce inflammation. It belongs to a class of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs), which work by inhibiting enzymes involved in the inflammatory process, specifically cyclooxygenases (COX-1 and COX-2). This action decreases the production of prostaglandins, which are chemicals in the body that promote inflammation, pain, and fever. As a result, ibuprofen effectively alleviates mild to moderate pain, such as headaches, toothaches, menstrual cramps, and muscle aches.

The other drugs listed serve different purposes. Diazepam is primarily used as an anxiolytic or sedative, Fluoxetine is an antidepressant that falls under the selective serotonin reuptake inhibitor (SSRI) category, and Phenobarbital is a barbiturate used mainly for its anticonvulsant properties and as a sedative. None of these are classified as analgesics, which is why they do not fit the question as well as ibuprofen does.