Table of Contents
Drug Tolerance
With the prolonged exposure or ingestion of a substance, substance tolerance can gradually develop. When the body develops a high tolerance to a drug, it indicates that the medication, at its present level, is no longer as effective as it once was. Therefore, a higher amount of the substance would be needed to elicit the same bodily reaction.1
When tolerance of drugs happens in the clinical setting, the doctor may need to adjust the dose, change the regimen, initiate a drug holiday, or prescribe a new drug. Opioid tolerance is prevalent in individuals who are administered the drug for pain relief and often need to have their doses increased as time goes by.2
Genetic and behavioral factors could cause drug tolerance. It can be developed even after a substance has been ingested for a few times. Individuals with high drug tolerance adapt faster to drugs than others.
What Are the Types of Drug Tolerance?
Drug tolerance can be reached in various ways, and there are several types of drug tolerance that include the following.
Pharmacodynamic Resistance
Pharmacodynamic tolerance of drugs occurs when the body builds up resistance to a particular substance due to continuous exposure to that particular substance. Cells contain receptors that get desensitized as they contact high concentrations of a substance. Therefore, as the cells in the body come in contact with the drug repeatedly over time, cellular response to these substances begins to reduce, leading to increased medication tolerance over time.
Increasing the concentration of the consumed substance can combat pharmacodynamic resistance. Although, it eventually gets to the point where any increase in concentration does not elicit any response from the cellular receptors.
Metabolic Tolerance
Metabolic tolerance, also referred to as pharmacokinetic tolerance, is a function of how the body processes introduced substances instead of the effect of the substance. For example, when drugs are taken into the body, the body absorbs them into the bloodstream. It’s then distributed to the different parts of the body, broken down, and ultimately expelled.
This process determines the effects of the drug on the body and the duration of these effects. Metabolic tolerance occurs when any of these processes are affected. For example, Suppose the body expels ingested substances faster than expected.
In that case, the duration of its effects on the body is reduced. Also, if the body fails to absorb the substance upon ingestion effectively, its effects are limited. Metabolic tolerance of drugs often occurs due to the increased production of enzymes that break down ingested substances or increase their clearance from the system.
Behavioral or Learned Tolerance
Behavioral tolerance occurs when some psychoactive substances are used repeatedly — leading to tolerance to the behavioral effects of that substance. Behavioral drug tolerance can happen due to drug-independent learning or pharmacodynamic tolerance in the brain. This occurs when an individual actively learns to overcome drug-induced impairment via practice or drug tolerance psychology.
Behavioral tolerance is frequently context-dependent, which means it’s influenced by the situation in which the substance is administered rather than the substance itself.
Conditioned Tolerance
When environmental triggers linked with prior substance administration are present, conditioned drug tolerance allows a higher dose of a drug to be tolerated. In the absence of such stimulation, delivery of the drug may result in an overdose.
Drug Tolerance Symptoms
While general drug tolerance and tolerance in drug addiction are still not fully understood, the most common indicator of drug or medication tolerance is when a particular substance does not have the expected effect on the user. Drug tolerance can also be experienced as a resistance to the side effects of a substance.
What Is the Difference Between Drug Tolerance, Dependence, and Addiction?
While drug tolerance, dependence, and addiction are similar and can be interrelated, they should not be confused with one another.
Tolerance occurs when the body no longer reacts to a particular substance as it’s supposed to due to psychological or metabolic factors. On the other hand, dependence occurs when an individual experiences varying degrees of withdrawal symptoms due to the absence or reduction in the intake of a substance.
With addiction, specific changes have been made to the brain due to substance use. In addition, with addiction, there is the inability to stop taking a substance regardless of the adverse effects of the substance on the individual’s health, work, and relationship with others.
While it’s much easier for a person who has developed a tolerance to a drug to stop taking it, especially as it no longer has the desired effect, the dependency would make the weaning process harder. While during substance use disorders like addiction, substance use cessation is extremely difficult voluntarily.4
Effects of Drug Tolerance
While drug or medication tolerance is often connected with its cons, it has some positive effects.5
Positive Effects of Drug Tolerance
Drug tolerance can help reduce or eliminate the side effects experienced by using a particular substance or medication. With increasing tolerance to drugs or a substance, fewer side effects are experienced.
However, perhaps the most significant advantage of tolerance is its ability to prevent the onset of drug dependence and addiction. If a substance fails to elicit any or heightened effects when ingested, such substance use would probably not continue.
Negative Effects of Drug Tolerance
A double-edged sword, drug tolerance’s most significant advantage is also a disadvantage. With heightened drug tolerance, an individual might have to take in more quantities of the substance to elicit the desired effect. But on the other hand, higher doses increase the likelihood of the adverse effects of substance use.
Medication tolerance can also result in a drug losing its desired effects on an individual, worsening their condition until a replacement drug is gotten. In some cases, cross-tolerance occurs. As a result, the individual develops a resistance to the consumed drug and other drugs of the same class, making it extremely difficult to treat their condition.
Treatment for Drug Tolerance, Dependence, and Addiction
Treating the tolerance of drugs can be challenging, and healthcare providers must review several options before deciding on the best course of treatment. In some cases, treatment methods are needed, including detoxification, residential care, and behavioral therapy. It’s important to note that withdrawal can be dangerous without proper medical intervention in drug tolerance treatment.
Contact Stillwater Behavioral Health
With a site in Montecito, Stillwater Behavioral Health is a cutting-edge substance use disorder treatment facility. We are fully equipped to tackle issues related to tolerance to drug addiction. Our programs are custom-made to provide each individual with a one-of-a-kind therapy experience to treat various degrees of drug tolerance.
Our goal is to help every individual reach and maintain sobriety. With sobriety, you or your loved one will be able to effectively regain control over your overall health, wellness, and life. Contact Stillwater Behavioral Health today; we look forward to working with you.
Resources
- https://n.neurology.org/content/30/12/1257
- https://www.medicalnewstoday.com/articles/drug-tolerance#fa-qs
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2628209/
- https://www.healthline.com/health/opioids-list
- https://pubmed.ncbi.nlm.nih.gov/31606310/
- https://www.healthline.com/health/drug-tolerance#vs-addiction
- https://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/conditioned-tolerance
- https://www.msdmanuals.com/home/drugs/factors-affecting-response-to-drugs/tolerance-and-resistance-to-drugs
- https://www.utoledo.edu/studentaffairs/counseling/selfhelp/substanceuse/marijuanatolerancewithdrawal.html
- https://www.sciencedirect.com/science/article/abs/pii/S0149763499000706?via%3Dihub