Acetaminophen relieves pain and fever by blocking nerve signals to the brain. NSAIDS, such as ibuprofen and naproxen, relieve pain and fever by reducing prostaglandins, or the hormone-like substance that causes pain. Aspirin is also an antiprostaglandin as well as a blood thinner, says FamilyDoctor.org.
Acetaminophen, one of the brand names of which is Tylonel, is a pain reliever used for aches and pains as well as for reducing fevers. Acetaminophen should not be combined with other blood thinners or used by those who drink more than three alcoholic drinks per day, advises WebMD.
Aspirin comes in brand names such as Bayer's and Excedrin and is used for pain relief, for fever reduction and as a preventative heart medicine, according to WebMD. Aspirin should be avoided by those prone to stomach bleeding or have stomach ulcers.
NSAIDS include ibuprofen and naproxen sodium. These medicines are commonly used to relieve aches and pains such as menstrual cramps, toothaches and arthritis. Examples of ibuprofen include Advil, Midol and Motrin. An example of naproxen is Aleve. NSAIDS can irritate the stomach lining and kidneys.
With all these pain relievers, it is advised that those with health problems, who are pregnant or who take other medications check with their doctor or pharmacist before using an over-the-counter pain reliever to find out which one is best for them, says WebMD.