Final answer:
Aspirin is the first-generation NSAID effective in reducing inflammation, pain, and fever, and can be purchased over the counter. It works by inhibiting the production of prostaglandins responsible for inflammation and pain, but may lead to severe side effects if misused.
Step-by-step explanation:
The drug that is a first-generation over-the-counter (OTC) NSAID and is very effective in reducing inflammation, pain, and fever is aspirin. Aspirin belongs to a class of medications known as nonsteroidal anti-inflammatory drugs (NSAIDs), which work by blocking the production of prostaglandins, substances in the body that cause inflammation and pain. Other common OTC NSAIDs include ibuprofen and naproxen. However, celecoxib is a prescription-only NSAID and belongs to the newer class of NSAIDs known as COX-2 inhibitors.
It is important to note that while aspirin and other NSAIDs are effective for managing inflammation, pain, and fever, they can also lead to side effects such as gastrointestinal ulcers and bleeds, heart attack, and kidney disease when used long-term or in high doses. As such, it is always recommended to use these medications in accordance with guidelines on the label or as prescribed by a healthcare professional.