What Are Narcotic Pain Killers (Pain Relievers)? - Opiates and Opioids

There are two types of narcotic analgesics: the opiates and the opioids (which are derivatives of opiates.)

Opiates are the alkaloids found in opium (a white liquid extract of unripe seeds of the poppy plant).

Opioids are any medication which bind to opioid receptors in the central nervous system or gastrointestinal tract. 

There are four broad classes of opioids:

• Endogenous opioid peptides (produced in the body: endorphins, dynorphins, enkephalins)
• Opium alkaloids (morphine, codeine, thebaine)
• Semi-synthetic opioids (heroin, oxycodone, hydrocodone, dihydrocodeine, hydromorphone, oxymorphone, nicomorphine)
• Fully synthetic opioids (pethidine or Demerol, methadone, fentanyl, propoxyphene, pentazocine, buprenorphine, butorphanol, tramadol, and more)

Opioids are used in medicine as strong analgesics, for relief of severe or chronic pain. There is no upper limit for the dosage of opioids used to kill pain or for pain relief, but it's important that the dose be increased gradually to allow for the development of tolerance to adverse effects like respiratory depression.

For some reason, some people with severe pain can take a high dose that would be fatal if taken by someone who was not suffering from any pain.

There have been many debates about opioids vs. the benefit of their analgesic or pain killing properties for treating non-cancerous or non-malignant chronic pain, like that of chronic arthritis. 

Some experts believe opioids can be taken safely for years with minimal risk of addiction or toxic side effects, but one should always seek out alternative options. 

All drugs, including narcotic pain killers, have side effects and all of them have to be analyzed by the liver and the kidneys.