Opioid analgesics : what is it ?

There are two types of narcotic/opioid analgesics:

the opiates and the opioids (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 opiod receptors in the central nervous system or gastointestinal tract. According to Wikipedia, 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. Interestingly, there is no upper limit for the dosage of opioid analgesics used to achieve pain relief, but the dose must be increased gradually to allow for the development of tolerance to adverse effects (for example, respiratory depression). According to eMedicine, "Some people with intense pain get such high doses that the same dose would be fatal if taken by someone who was not suffering from pain."

There have been debates over the addictive potential of opioids vs. the benefit of their analgesic properties for treating non-malignant chronic pain, such as chronic arthritis. Some experts believe opioids can be taken safely for years with minimal risk of addiction or toxic side effects. The enhanced quality of life which opioids may provide the patient must be considered.