Pain relievers are medicines that reduce or relieve headaches, sore muscles, arthritis and any number of other aches and pains, according to Medline Plus. While most pain relievers are available over the counter, some are only available with a doctor's prescription. The U.S. Food and Drug Administration requires that all OTC medications have an approved Drug Facts label describing the product's active ingredients and how they work. There are two basic types of over-the-counter pain relievers: acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs). Aspirin, ibuprofen and naproxen sodium are typical examples of NSAIDs.
Acetaminophen
Acetaminophen is an analgesic that alleviates mild to moderate pain. Acetaminophen is commonly used to treat conditions such as headaches, muscle aches, toothaches, backaches and colds and sore throats. Acetaminophen may also be used to relieve the pain of osteoarthritis, according to Medline Plus. It works on the pain receptors of the body and changes how the brain and nervous system respond to the pain.
Acetaminophen also lowers fever by causing the hypothalamus, the portion of the brain that regulates body temperature, to override interleukin-induced temperatures. Interleukin, a chemical produced by lymphocytes that helps regulate of the immune system, can raise body temperature in an attempt to fight off infection. Acetaminophen causes the body temperature to adjust itself to within a set range of temperatures.
Acetaminophen comes in tablets, capsules, suspensions, solution and drops. It is commonly sold under the brand name Tylenol.
Aspirin
Aspirin is a white crystalline derivative of salicylic acid used to treat mild to moderate pain and fever by breaking down substances in the body that irritate the nerve endings. Aspirin induces sweating to dissipate heat through evaporation; the result is a reduction in body temperature. Aspirin is sometimes used to lessen the chance of heart attack, stroke and chest pain or angina. Aspirin should be used for cardiovascular conditions only under the supervision of a doctor, according to Drugs.com.
Aspirin should not be given to a child or teenager who has a temperature of 104 Fahrenheit or higher, especially if the child has chickenpox or flu symptoms. Aspirin can cause a rare and potentially fatal disorder in children called Reye's syndrome, which causes uncontrolled spasms.
Ibuprofen
Ibuprofen is a non-steroid drug used to treat osteoarthritis and rheumatoid arthritis and relieve pain, fever and swelling. It restricts the body from producing prostaglandins, or unsaturated cyclic fatty acids. Like any other non-steroidal drug, ibuprofen produces a number of side effects in humans, including ulcers--bleeding or holes in the stomach or intestine. It comes in tablet form and can be used in combination with other drugs.
