Humans have had a difficult relationship with opiates: One of the earliest drugs known to mankind, they’ve offered comfort during surgery and hope to those in chronic pain. They’ve also been the cause of countless deaths, and have plagued its users with addiction. What is an opiate? How are they used and why are they so addictive and dangerous?
Opioids are drugs that act directly on opioid receptors. Technically, opiates are opiods derived directly from the poppy plant. However, the words “opiate” and “opioid” are used interchangeably.
Opioids react with four chemical receptors in the body, affecting a range of bodily functions including pain, physical dependence, appetite, sedation, gastrointestinal motility (digestion speed,) vascular dilation and depression. Most of these receptors are located in the central and peripheral nervous systems as well as the gastrointestinal tract.
The body regulates the receptors by producing and releasing opioids including endorphins, endomorphins, dynorphins, enkephalins and nociceptin.
These drugs are extremely effective at combating pain and are used mainly to control chronic pain issues. Since the opioid receptors control such a wide range of functions, activating them causes several side effects including sleepiness and constipation. In the past, these drugs have been used to treat coughs, diarrhea and cardiovascular problems, but they’ve been replaced by safer, less addictive drugs.
At low doses, these drugs are effective at controlling pain, but higher doses can cause euphoria, making them attractive for recreational use. This makes them tempting for both casual users and patients who have access to prescription medications. Because pain is a self-reported symptom, it’s easy for patients to request more opiates than they need for pain control so they can experience a high, while many others become so resistant to opioids that it takes massive doses to maintain pain levels.
Opiod use has antidepressive, anxiolytic (anti-anxiety) and antipsychotic effects. It is believed that long term use deregulates the function of opioid receptors, effectively requiring a certain amount of opiods in the user’s system to restore normal functionality.
If the receptors are overloaded, the central nervous system and respiratory system will be depressed to a point that the heart and lungs will stop functioning, killing the user. To prevent this, an antagonist like Naloxone can be used to fill in receptors, preventing opiate uptake.
Because opioids attach to receptors handing a wide range of functions, there are dozens of possible side effects. Withdrawl effects can be very severe, making relapse common even with those who undergo intensive long-term rehabilitation programs.
Recovery can be divided into six stages, with each stage adding new symptoms. Times are given for morphine addiction; other drugs will have differing timeframes for recovery.
Opiate addicts can relapse by taking any opiate, not just the drug that drove their original addiction. This means that all opiates are unsafe for medical treatment in these individuals.
While poppy plants contain several opiates, this is the most common, accounting for 14% of the plant’s weight in wild species; plants cultivated specifically for drug production can be as much as 26% morphine. This was the first opioid extracted from poppy plants; medicinal use dates back to the early 19th century. Abuse was rampant in the Victorian era: laudanum, a mixture of morphine and alcohol, could be bought over the counter at any pharmacist. Claimed to be a panacea, it was used excessively, making it extremely easy to become addicted.
The pain-killing properties of medicines are usually expressed in relation to a dose of morphine. For example, an aspirin is 1/360th the strength of morphine. The drug is active from two to three hours when injected and as long as 6 hours when taken orally.
Diamorphine was first synthesized by C. R. Alder Wright and later marketed by Bayer Pharmaceuticals under the trade name “Heroin.” At the time, morphine was used as a cough suppressant; by modifying morphine, Wright hoped to develop a drug that was effective without morphine’s addictive properties.
Heroin itself is active for about half an hour, but the liver rapidly converts it into morphine. As a result, it’s a faster, longer lasting way of delivering morphine to the system than its pure form, resulting in pain-killing effects that are 5 to 6 times as powerful as straight morphine. Instead of creating a non-addictive drug, Wright and Bayer had made morphine addiction worse, leading to the regulation of opiates and a worldwide ban on diamorphine production.
While all opiods cause respiratory depression, heroin users adjust quickly to this effect, then rapidly return to normal function during withdrawl. Users that relapse often take the same dose as they did previously, but the lower drug resistance leads to cardiovascular failure and death. This is why many heroin-related deaths cannot be ruled specifically as being accidents or suicides.
A dose of codeine is 36 times as powerful as a dose of aspirin, or one tenth as powerful as a dose of morphine. The drug is active from two to three hours. It also has synergism with acetaminophen, making the combination of both drugs stronger than either used individually. Although it occurs naturally in poppies, most commercial forms are made synthetically.
Other Synthetic Opioids
The diamorphine ban led to the development of dozens of other synthetic opiods that remained legal under regulation, but by 1930 all opiates had come under worldwide regulation.
Methadone doesn’t have the euphoric effects of other opioids, but it does mitigate the effects of withdrawal. This drug is used in rehabilitation, allowing patients a way to gradually readjust their receptors to function without opiates while reducing the severity of withdrawal symptoms.
Loperamide is used to combat severe diarrhea, not pain control. It is rarely a direct cause of addiction, but can cause problems for those with a history of drug abuse.
Carfentanil is the strongest opiod in medical use: It’s 10,000 to 100,000 times as potent as morphine. This potency means its rarely used outside of sedating large animals, but it may have been used in a form of chemical warfare. The Russian military will not deny or confirm that an aerosol version of this drug was used in the Moscow Theater Hostage Crisis, but the warned paramedics that they would need anti-opiod drugs on hand to treat victims. Clothing and urine analysis later confirmed the use of carfentanil.