Analgesics are available in one of two primary forms: non-narcotic and narcotic.

Non-narcotic analgesics are milder forms of the painkillers that include acetaminophen. It works by preventing the production of prostaglandin, a substance that sensitizes pain receptors as a means of stimulating pain and inflammation.

By interfering with the role of prostaglandins, a patient’s perception of pain is reduced.  Acetaminophen is found in hundreds of over-the-counter medications. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) are not technically analgesics according to some definitions. However, because they share many of the same properties, they are treated as such for the purpose of therapy. Examples of non-narcotic analgesics include:

Many other non-narcotic drugs have analgesic effects. For example, the only drugs approved by the U.S. Food and Drug Administration to relieve painful diabetic neuropathy are an antidepressant and an anticonvulsant (seizure medication).

Narcotic analgesics (opioids) are strong analgesics that can be used when pain signals are too severe for non-narcotic analgesics to control. These drugs work on the central nervous system to relieve pain. In some cases, they are also given just before or during an operation to help increase the effectiveness of an anesthetic. The dosage level of a narcotic is closely controlled by a physician so that it is just enough to relieve the pain. Dosage levels can be adjusted as necessary.

Narcotic analgesics include:

There is also an analgesic called tramadol that may be considered an atypical opioid.

In some cases, a narcotic analgesic may be used in combination with a non-narcotic analgesic to increase the pain-killing effect. Such combinations may also have the benefit of requiring a lower amount of each drug to be effective, thus minimizing the side effects of each medicine.

Most medical societies have made recommendations to use a stepwise approach for pain medications depending upon the severity of the pain.