Analgesic drugs are commonly referred to as painkillers. The word analgesic is derived from the Greek prefix an-, which means "without," and algos, which means "pain." Analgesic drugs work through interaction with the peripheral and central nervous systems, essentially blocking pain signals before they can reach the brain and produce the sensation of pain. The two major categories are narcotic analgesics (also known as opiates or opioids) and non-narcotic analgesics. Non-opioid analgesics include the most commonly used pain killers, which are generally available over the counter. In the US, opiates usually cannot be obtained without a prescription from a doctor.
Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common analgesics used to reduce headaches, everyday aches and pains, and discomfort from chronic conditions such as arthritis. They relieve both inflammation and pain, and also tend to work to reduce a fever, but some have also been linked to kidney and liver damage when used in excess of recommended dosages. While all NSAIDs provide the same type of pain relief, many individuals find that certain types of NSAIDs work better than others. Additionally, different types of NSAIDs have different side effects and contraindications.
Aspirin is generally the easiest to find and least expensive of the pain relief medications. In addition to its usefulness as a pain reliever, aspirin can be helpful in preventing heart attacks and strokes because of its blood-thinning effects. The side effects of aspirin use can include gastrointestinal ulcers, stomach bleeding, and tinnitus.
Like aspirin, ibuprofen is among the most popularly used analgesic drugs. It is widely available without prescription and is especially effective when pain coincides with inflammation. Adverse side effects of ibuprofen can include nausea, indigestion, diarrhea, and hypertension. Ibuprofen is widely available under the trademarks Advil® and Motrin®, among others.
Naproxen is another common analgesic that falls under the NSAID category. It is widely available under the brand names Aleve® and Midol®. In some regions, the drug is sold over the counter, while in others a prescription is required. Serious side effects of naproxen that should be reported to a doctor can include constipation, blisters, and yellowing of the skin or eyes.
Rounding out the common, over-the-counter analgesics is acetaminophen, commonly available as Tylenol®. Acetaminophen — known as paracetamol outside of North America — which is not an NSAID, is known for not irritating the stomach, as ibuprofen can, but it can also be hard on the liver. Some prescription analgesics combine opiates such as oxycodone or hydrocodone with acetaminophen.
Analgesic drugs that fall under the narcotic category are more heavily regulated than NSAIDs. These medications are used in cases of acute pain and are generally not prescribed for use over extended periods of time. They include codeine, demerol, and oxycodone. Narcotic analgesic drugs may be prescribed after surgery to relieve the pain of healing. They may be referred to as opioids or opiates because they are derived from the opium plant.