# Opioids --- **Opioids** are a class of [[medicine]] that are very effective [[analgesic|painkillers]]. The prototype drug is morphine which was the first refined opioid invented. Opium is the original form, derived from the seed of the poppy flower grown in many parts of the world. >[!warning] That Beguiling Poppy Seed >Opioids are *dangerous*. Too much can kill you. And they are *addictive* so they can easily be the target of theft, diversion and misuse. Be careful. But also be aware that most people who are prescribed opiates for acute pain do not become addicted; there has to be more going on then just that. [[Opioid use disorder]] is a mental illness where an individual has a intense desire for and a compulsive need to use opioids, despite negative consequences to their lives. ## Mechanisms of Action Opioids work in a couple different ways, but the mu agonist is used much more. - **Mu agonists** are ones that we usually see: - morphine - hydrocodone - fentanyl (this is the most powerful opioid that we have) - oxycodone - **agonists - antagonists** you don't really see these as much, I think they're used in the treatment of opioid use disorder. - buprenorphine - nalbuphine - butorphanol ## Adverse Reactions Opioids are a [[central nervous system|CNS]] depressant, so it reduces [[respiration rate]], heart rate and blood pressure as well as causing [[blood vessels|vasodilation]]. There can be a euphoria related to opioid use, and that dizzy, high or sleepy feeling makes patients a fall risk. Another extremely common common side effect is [[constipation]], as it decreases motility of the intestines. Overdose is a dangerous, as the depression to respiration rate can reduce it so low a person dies of lack of perfusion. The overdose reversal agent, [[opioid antagonists|naloxone]] can be administered, which immediately removes the opiate from the synapses and just doesn't feel that great. ## Tolerance, Physical Dependence & Addiction **Tolerance**, **physical dependence**, and **addiction** are all potential side effects of taking opioids, particularly for extended periods of time. - **Tolerance** is when you need a higher dose of the drug to do the same job, thus decreasing it's effects. It is a normal response to a regular use of opioids. - **Physical dependence** is when one undergoes withdrawal symptoms if the use of stopped. It is a normal response to opioid use of 2 weeks of more. - **Addiction**, in this case, [[opioid use disorder]] is a compulsive use and craving for drug for it's effects other than pain relief. It is chronic, relapsing and importantly, treatable. It's influenced by genetic, psychosocial and environmental factors. It's important to understand and explain to patients that *taking opioids for pain relief is not addiction*. ## Overdose - pinpoint pupils - altered LOC -> stupor to coma - respiratory depression ## Examples - **Morphine** is an **opioid agonist** used to treat pain. It's a very powerful [[analgesic]]. - Morphine is the main alkaloid of opium and was first obtained from poppy seeds in 1805. It is a potent analgesic, though its use is limited due to tolerance, withdrawal, and the risk of abuse. Morphine is still routinely used today, though there are a number of semi-synthetic opioids of varying strength such as codeine, fentanyl, methadone, hydrocodone, hydromorphone, meperidine, and oxycodone. - **Hydrocodone** is an opioid agonist used to treat [[pain]] but also cough (for some reason). - **Hydromorphone** (brand name: **Dilaudid**) - [[opioid use disorder|Methadone]] is a synthetic opioid used for treatment of opioid use disorder. ___