Drug overdose is the leading cause of death for Americans under the age of 50. Opioid overdose in particular has become a huge problem today. In 2015, 33,091 people died of opioid overdose—a rate that has quadrupled since 1999, and a large number of these deaths are linked to drug tolerance issues.
Opioids are incredibly useful medications—they allow patients to receive life-saving surgeries without experiencing shock and trauma from the pain, and they ease suffering in the terminally ill, so patients can die in comfort and dignity. However, opioids are not effective treatments for ongoing, chronic pain, due to the dangers of side effects, tolerance, addiction, and overdose. But opioids aren’t the only source of danger. Any addictive drug, or alcohol, can create tolerance in the body, and changes in tolerance can far too easily lead to an overdose in individuals who misjudge their tolerance and consume too much of an addictive substance.
What is Tolerance?
Tolerance definition according to the National Institute on Drug Abuse: “A state in which an organism no longer responds to a drug; a higher dose is required to achieve the same effect.” When you repeatedly use a drug, your body gets used to the effects and starts to adapt; this leads to tolerance.
In the case of opioids, the drug binds to opiate receptors in the brain and activates chemical reactions, such as the release of dopamine, which results in pain relief, sedation, and euphoria if taken in a high enough dose. After the brain’s opiate receptors have been activated in this way repeatedly, the brain learns how to adapt to prevent the unnatural effect from continuing to occur when the drug is taken. The user is then required to take more of the drug to overcome the resulting tolerance. A larger dose will work temporarily, but the brain has already learned how to adapt to the substance, and will continue to adjust to the larger dosage, so that higher and higher levels of tolerance develop.
This same effect occurs with alcohol and other, non-opiate drugs as well, and tolerance to any substance makes you extremely vulnerable to addiction. Most addictive substances work on the brain’s dopamine levels, and tolerance will gradually create dependence to these substances, as the body stops producing the usual amount of dopamine and the user becomes unable to feel satisfaction, reward, and pleasure reactions without turning to the addictive substance. Their brain chemistry has been changed by drug or alcohol use, and these changes have profound consequences. Over time, having to increase the number of drugs or alcohol the user is now dependent upon will create and intensify painful withdrawal symptoms that will occur if the user stops taking or cuts down on the substance, which will make giving up the drug increasingly difficult. Meanwhile, tolerance can cause an overdose, as the user continues to take larger and more dangerous amounts of a drug.
Types of Tolerance
Drug or alcohol tolerance is a state of diminished responsiveness to a substance that occurs after repeated use. There are many different types of tolerance that you can develop, but the three primary physical types are: metabolic, pharmacodynamic, and tachyphylaxis.
Metabolic tolerance causes your body to metabolize a substance faster the more often you take it. The drug may still be affecting your brain, but your body gets rid of it too quickly now, leading to an overall diminished effect.
Pharmacodynamic tolerance is when the brain has adapted to the substance by reducing the chemical reaction stimulated by the drug, so that higher doses are needed to stimulate the same effect.
Tachyphylaxis is a form of tolerance that happens very quickly, and can begin with the first instance of use. Tachyphylaxis is the reason why your first drink or two will increase your level of intoxication much more rapidly than the drinks you consume later on, even if the alcohol content in each drink is exactly the same. This effect can also be called acute tolerance.
There are also more psychologically based forms of tolerance that can contribute to addiction and overdose, such as behavioral and conditioned tolerance. Behavioral tolerance occurs as the user starts to develop certain expectations of a substance’s effects, and the resulting anticipation and eagerness for the high (or pain relief, or sedation) the substance will cause them to experience leads the user to increase their dosage. Conditioned tolerance is when environmental or situational cues trigger a person’s compulsion to use drugs. For example, if someone repeatedly turns to amphetamines when they are feeling stressed about how much work they have to do, very soon, any feelings of stress they encounter will automatically give them the urge to take amphetamines.
Both behavioral and conditioned tolerance lead to more frequent and larger consumption of substances, which in turn amplifies the other, more physical forms of tolerance. Together, these various forms of tolerance cause dependence and addiction, as the brain becomes reliant on the addictive substance to maintain normal levels of neurotransmitter chemicals. At this point, users will start to find it very difficult to get high from the substance they have become addicted to, but will be nevertheless compelled to keep using larger amounts of it to ward off withdrawal symptoms and feel “normal.”
Another way in which tolerance can lead to addiction and overdose has a genetic component. A scientific study of alcohol tolerance in rats found that the animals that preferred drinking alcohol over water developed an acute tolerance to some of the effects of alcohol much faster than the rats who preferred drinking water. What does this mean for people? Well, it could be that some humans have a tendency to become tolerant to alcohol or drugs faster than other people do, which would lead to increased consumption, further intensified tolerance, and eventually addiction. This is why it should always be regarded as a warning sign when you or someone you love starts to develop a tolerance to any drug that they are taking.
Changes in Tolerance Can Lead to Overdose
Changes in tolerance can cause an overdose, whether the tolerance is newly higher, or newly lower. While it may seem logical that a higher tolerance for a drug would keep you safe from an overdose, drugs have multiple, complicated effects, and your tolerance to these effects will not usually develop at the same rate. For example, opioid users may quickly become tolerant to the pain relieving effects of a drug, but still experience the same amount of respiratory depression in reaction to it. Increasing their dosage will put them at risk of not getting enough oxygen to their cells, or of even stopping breathing altogether. To get the amount of pain relief necessary to not suffer after a surgery, a long-term user of opioids will likely need to take a dose that puts them at high risk of respiratory arrest. Many overdoses occur in people who are merely attempting to ease physical pain.
Low tolerance can cause an overdose in individuals who have recently been released from opioid addiction treatment programs or from prison. A recent study examining 103 opiate-addicted individuals who had detoxified from opiates at a 28-day inpatient program found that five of the patients had died of a drug overdose within the next year, three of them in the first four months after being discharged. The sad truth is that patients who have successfully detoxed from opiates are more likely to die of an overdose in the year after treatment than those who did not complete their treatment program. This is because detoxing from a substance causes you to lose your tolerance to that substance. If you relapse and return to drug use after treatment, you will be unable to accurately judge how much of the drug you can safely take without suffering an overdose.
Dealing with Addiction Treatment and Reduced Tolerance
To ensure your safety after detoxification from an addictive substance, it is crucial to receive an adequate amount of follow-up treatment after detox, and to make good use of aftercare services following discharge from any rehab program you take part in.
The best course of action for any addiction is to begin with an inpatient rehab program that provides medical treatment and monitoring to keep you safe and comfortable during detox. Ideally, you should stay inpatient a while longer, even after being fully detoxed, so that you can benefit from counseling and behavioral training that will help you stay off drugs once you’re back out in the “real world.” At least 90 days of rehab is recommended for a successful recovery from drug or alcohol addiction. These 90 days can all take place in an inpatient or residential setting, or they can be part of an outpatient program where you receive treatment during the day/evenings/weekends, and then return home to sleep at night. No matter what type of rehab program or programs you take part in, the key is to make sure you get enough treatment to give you the necessary knowledge and skills to maintain a healthy life free from addictive substances.
Aftercare Following Addiction Treatment Can Reduce Your Risk of Overdose
Addiction recovery is a lifelong commitment, not a treatment that stops at a certain date and leaves you cured. Addiction is a chronic, relapsing disease, similar to other medical diseases such as asthma, hypertension, and diabetes. Such medical conditions can be successfully treated, but they can never be ignored altogether; neglecting the conditions will lead to relapse and dangerous health complications. The same is true with the disease of addiction.
A good addiction treatment facility will work on a discharge or aftercare plan for each patient before releasing them from the program. These plans detail steps that the former patient will take to stay healthy and avoid relapse. Some rehabs have their own aftercare programs that include continued counseling, periodic drug testing, follow-up appointments, mental health tracking apps, and alumni events, but those that do not will often refer individuals to aftercare programs elsewhere, or to other community support services, such as 12-step meetings or non-12-step peer support groups.
This kind of follow-up treatment is crucial for anyone’s recovery success. The brain and body can take a long time to fully heal from drug addiction, and many of the feelings, habits, and behaviors that develop during drug use stick around even after the substance in question has been removed from the body. A return to “normal” life and independent living should never be rushed after treatment, and addiction treatment should never cease completely, but should only decrease in intensity. For example, you might no longer receive weekly individual counseling, but still attend a weekly group therapy session. Free addiction support groups are also available in most areas, and are a practical way to stay on track with your recovery progress, as well as stay socially connected to a community of sober individuals.
Good aftercare will also include services that improve the former patient’s overall quality of life, so that they are not as vulnerable to relapse. Some of these services include housing, vocational training, job placement, child care, legal help, medical care, transportation, and financial advice. A sense of purpose, and meaningful social connections are just as important to recovery as avoiding drug use triggers. Recovery is a whole-life process, and an ongoing journey without a definitive end. Caring for yourself and for your recovery through quality aftercare services can help you avoid the easily fatal overdoses that so frequently follow addiction treatment due to a reduced drug tolerance.