Opioid

Opioids are a group of drugs that come from or act like substances found in the opium poppy plant. They work on special parts of the brain and body called opioid receptors to create effects similar to morphine, mainly helping to relieve pain.

These drugs are used by doctors to manage pain, including during surgeries, and for other purposes like stopping severe diarrhea, treating dependence on opioids, and stopping cough. However, opioids can also be used by people for pleasure because they create a feeling of happiness, but this use can be very dangerous.

Opioids can cause many side effects, such as itching, feeling sleepy, feeling sick, and trouble breathing. Long-term use can lead to the body needing more of the drug to work the same way and can make stopping the drug very difficult. Because of these risks, most opioids are closely watched and regulated.

Terminology

Opioids are drugs that come from or act like substances found in the opium poppy plant. They help with pain and include natural drugs like morphine, as well as man-made ones like hydrocodone, oxycodone, and fentanyl. Some opioids can block the effects of others, like naloxone. The word "opiate" is an older term for opioids that come from opium. Sometimes, people use the word "narcotic" to mean opioid, but this word can have negative meanings and is not always the best choice.

Medical uses

Opioids are medicines that help to ease pain. They are often used for short-term pain, like after surgery, because they work quickly. They can also help people with serious, ongoing pain from conditions such as cancer. However, using opioids for a long time can have risks, so doctors are careful when prescribing them.

Opioids are sometimes used for other purposes, like stopping a cough or controlling certain stomach problems, but they are not always the best choice. For example, they are not recommended for children with a cough. Doctors also use opioids to help with breathing problems in very serious illnesses. But, it’s important to remember that using opioids for a long time can sometimes make pain feel worse instead of better.

Adverse effects

Opioids can cause many different effects in the body. Some common ones include itching, nausea, vomiting, constipation, drowsiness, and dry mouth. Others include dizziness, loss of appetite, and slowed breathing.

Long-term use of opioids can lead to dependence, where the body gets used to the medication. This means that stopping suddenly can cause withdrawal symptoms. Some people may also build tolerance, needing higher doses over time to get the same effect. Opioids can also sometimes make pain feel worse in some individuals.

Using opioids can affect work and daily activities, especially for tasks that need full attention, like driving or operating heavy machinery. It’s important to use opioids carefully and follow a doctor’s guidance.

Interactions

Doctors who give opioids to patients along with other medicines must keep good records and watch closely. This is important because mixing opioids with certain medicines can be very dangerous.

When opioids are taken with other medicines that slow down the body, like some sleeping pills or alcohol, it can increase the chance of serious problems, including stopping breathing. Doctors can help reduce these risks by watching patients carefully and adjusting treatment as needed.

There are special medicines called opioid antagonists, such as naloxone or naltrexone, that can stop the strong effects of opioids. These medicines work by blocking the parts of the body that opioids affect. They are especially helpful if someone has taken too much opioid and needs emergency care. However, using these medicines requires careful planning to make sure pain relief is still provided while keeping the person safe.

Pharmacology

See also: Opioid receptor

Opioids connect to special places in the body called opioid receptors. These receptors are found in the nervous system and other parts of the body. There are three main types of opioid receptors: μ, κ, and δ, but scientists have found up to seventeen different ones. These receptors are important because they help control pain and other body functions.

When an opioid connects to a receptor, it can do different things in the body. For example, the drug morphine helps with pain when it connects to the μ₁ receptor, but it can cause breathing problems when it connects to the μ₂ receptor. Each type of receptor and each opioid drug works in its own special way, which is why there are many different opioids with different effects.

Functional selectivity

Scientists are now trying to design new drugs that focus on the good effects while reducing the bad ones. This idea is called functional selectivity or biased agonism. One example is a drug called oliceridine, which was made to help with pain but have fewer side effects.

Opioid comparison

Main article: Equianalgesic

Researchers have studied how strong different opioids are compared to each other. They use tables called equianalgesic tables to find out how much of one opioid is needed to have the same effect as another. These tables help doctors choose the right opioid and dose for patients.

Usage

In the 1990s, doctors started prescribing opioids more often. These medicines were originally used for severe pain, like from cancer, but are now given for long-term pain too. This has led to many people becoming addicted to these medicines and some even dying from taking too much. The United States and Canada use more of these medicines than many other places in the world. Some groups, like First World communities and people with less money, have been especially affected. Experts say this may be because other ways to manage long-term pain are not always available or too expensive. While opioids can help with pain, it's important to think about the risks they pose. In 2017, about 3.4 percent of people in the U.S. were prescribed opioids to manage daily pain. There have been efforts to reduce the use of these medicines, but more research is needed to know what is safest for people with long-term pain.

International Narcotics Control Board First World opioid epidemic opioid tapering

History

Naturally occurring opioids

Opioids are some of the oldest drugs known to people. The earliest signs of the opium poppy in human history go back to around 5,700–5,500 BCE. Seeds from this plant have been found in places like the Iberian Peninsula and the Italian Peninsula.

People have used the opium poppy for thousands of years for healing, enjoyment, and spiritual reasons. Ancient writings from places like Sumer mention its use. The Egyptians wrote about it as a way to help soothe children and treat infections. The Greeks, including Hippocrates, valued it for helping people sleep and easing pain.

Laudanum

In the past, the word "laudanum" was used for many useful medicines. Later, it came to mean a mix of opium and alcohol. One famous recipe from the 1600s mixed opium with wine and spices. This mixture was used for many years in Europe and the Americas. Other opium-based medicines included Paregoric for children, Black-drop for stronger needs, and Dover’s powder.

The opium trade

Opium became a big part of trade between many countries. The British East India Company started selling opium from India in the 1700s. This trade led to conflicts, including wars between China and Britain over opium.

Morphine

In the 1800s, scientists made important discoveries about opioids. A German scientist named Friedrich Sertürner was the first to separate morphine from opium in 1804. Later, new ways to give medicine under the skin were developed, making it easier to give exact amounts of morphine.

At first, morphine was seen as a wonderful medicine for pain and helped people sleep. It was used during wars and for many health issues. But people later found that it could be habit-forming.

Codeine

Another opioid called codeine was discovered in 1832. It came from studying the leftovers of morphine processing. This discovery led to new medicines for coughing and diarrhea.

Semi-synthetic and synthetic opioids

In the 1900s, scientists created new types of opioids. Some of these were stronger than older ones. For example, heroin was made in 1874 but was stopped when its habit-forming nature was noticed. Other new opioids included oxycodone, hydrocodone, and fentanyl, which is much stronger than older opioids.

Criminalization and medical use

Laws were passed to control the use of opioids. In the United States, the Harrison Narcotics Tax Act of 1914 made non-medical use illegal. Later, guidelines were created to help doctors prescribe opioids safely for pain. In the 1990s, strong marketing led to more opioid use, which caused health problems. This led to new rules in 2016 to reduce opioid prescriptions.

Society and culture

The word "opioid" started being used in the 1950s. It comes from "opium" and ends in "-oid," which means "like opiates." Opium comes from a special flower, and opiates are drugs like morphine made from it. Scientists found that these drugs work by turning on special tiny parts in our bodies called opioid receptors.

In the United States, leaders have worked to help people avoid using these drugs too much for fun. In 2017, the government said this problem was a big health emergency. Some places track who gets these drugs to make sure they are used safely. Doctors are encouraged to use the smallest amount needed and to avoid mixing these drugs with others that can be dangerous.

Unfortunately, some people use these drugs just to feel very happy, even if they don’t need them. This can lead to serious problems. Many countries are trying different ways to make sure people who are in a lot of pain can get the help they need, especially in places where these medicines are hard to find.

Veterinary use

In the 1600s, scientists first tested opium, a plant-based substance, on animals. They gave it to dogs and observed its effects, such as making them sleepy or causing other reactions. Later, researchers found that different animals responded differently to these substances. For example, cats and horses showed signs of confusion, while dogs became unconscious.

Today, these substances are used in animal medicine to help relieve pain, and they can be given in various ways, such as under the skin or into a vein. Common options include morphine, fentanyl, and buprenorphine. However, there are strict rules about using these substances in farm animals to ensure safety and proper record-keeping.

Classification

There are several types of opioids:

• Natural opioids: These come from the opium poppy plant and include substances like morphine and codeine.
• Semi-synthetic opioids: These are made from natural opioids and include drugs like oxycodone and hydrocodone.
• Fully synthetic opioids: These are made entirely in a lab and include fentanyl and methadone.
• Endogenous opioids: These are natural pain-relieving chemicals that our bodies make, such as endorphins.

Opioids work by attaching to special receptors in the brain and other parts of the body to help reduce pain. Some opioids can also affect mood and energy levels.