What Does Science Say About Opioids and Opiates?

07 March, 2021
Although we associate opioids with drugs like heroin, our body naturally produces these substances too. In this article, we'll tell you all about them and what they do.

Opioids and opiates are different. Although many people believe that opioids are just external drugs that cause addiction, that’s not entirely true.

Humans have used opiates as painkillers for thousands of years. At least for six thousand years, humanity has recognized their soothing properties. Furthermore, in 1086, we were able to chemically isolate the substance that we now know as morphine.

Science has progressively discovered that the human being has internal systems to interact with opioids. These receptors, dispersed throughout the human body, are there for physiological reasons, which we can divide into two categories:

  • Opioid: We use this term for all substances, regardless of their origin, that can bind to an opioid receptor in the body.
  • Opiate: These are substances derived from opium that have opioid action. As such, they don’t naturally develop in the human body. An example of this would be morphine.

All opiates are opioids, but not all opioids are opiates. Some opioid substances that circle in the blood, like endorphins, are natural, so don’t require specialist intervention to obtain them from opium; they aren’t opiates.

We also have a subdivision within the opiates group, that distinguishes between natural origin or synthetic. There are opiates that the opium plant directly makes and others that specialists artificially make. Both the pharmaceutical industry and the world of designer drugs have developed these synthetic products.

Endogenous opioids

There’s a group of opioids that doesn’t exist outside of the human body and are intrinsic. By this, we mean that the human body makes these substances and they play a part in different natural bodily processes.

Scientists John Huges and Hans Kosterlitz discovered these so-called endogenous opioids in 1975. They were able to identify three groups:

  • Endorphins
  • Enkeyphalins
  • Dynorphins

Endogenous opioids have varied functions, from acting as painkillers to medication for stress responses. They’re also linked to cardiac function and with the immune system against infections.

The body is able to collect endogenous opioids to use them when it needs to. But, on the other hand, the body can’t collect endogenous cannabinoids. These are simply made when they’re needed.

Receptors in the body.

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How do opioids soothe pain?

One of the main characteristics of opioids is their analgesic propertiesThey effectively calm pain and several of them don’t have a limit to this action. These are, therefore, used in treatment for chronic pain.

Endogenous opioids are also analgesics. For that reason, when we secrete more endorphins because we’re happy, our pain reduces. Similarly, the same can happen when people with arthritis; their endorphin levels increase when practicing a sport they enjoy, and, as a result, they suffer less.

According to their analgesic action and to which receptors in the central nervous system they bind, medical opiates are classified in the following categories:

  • Pure agonists: These are the ones that act on the receptors specialists have identified with the Greek letter μ. They’re strong painkillers and cause euphoria. Morphine is in this group.
  • Agonists-antagonists: Medication like nalbuphine is in this group.
  • Partial agonistsA great example of this would be buprenorphine.
  • Pure antagonists: These medications are capable of reverting the effect of other opiates. Specialists use them to treat morphine intoxication. We can also mention naltrexone and naloxone in this group.
Opiomorphine.

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Adverse effects

Just like with any substance, natural or artificial, an excess can cause intoxication and adverse effects. Opioids aren’t exempt from this.

Normally, the adverse effects appear with opiates when people use them for medication or recreation. Endogenous opioids don’t reach the point where they can generate these undesired reactions because the body regulates them.

Among the adverse effects of opiates we can mention:

  • Digestive disorders: Especially constipation, because opiates tend to reduce the peristaltic movements in the digestive tract. The individual may also experience nausea and vomiting.
  • Dizziness and drowsiness.
  • Headaches.
  • Increased sweating.
  • Respiratory depression: A very worrisome effect of opiates is the possibility of shallow and ineffective breathing, which can then cause death. For that reason, dosage administration must be supervised.
  • Addiction: Opiates cause addiction in both those that use them as painkillers and those who use them as recreational drugs. The addicted individual experiences the irresistible need to consume them and each time they have to take a higher dose to achieve the same effect. It’s a huge social problem that requires approaches from different perspectives, not just a medical one.

In conclusion

Opioids are known for their potent painkilling action. In fact, due to their ability to treat pain, specialists use them for diverse types of pain. However, you must use them with caution as they usually produce an addiction when taken as medication or recreationally.

  • Akil, H; Meng, F; Devine, D.P; Watson, S. J .Molecular and neuroanatomical properties of the endogenous opioid system: implications for treatment of opiate addiction. Semin Neurosc, 1997, 9: 70-83.
  • Endogenous opiates and behavior: 2007. Peptides. 2008;29:2292-2375.
  • Flórez J. Fármacos analgésicos opioides. En: Flórez J, Armijo JA, Mediavilla A, editores. Farmacología humana. 4a ed. Barcelona: Masson; 2003. p. 461-478.