Understanding Tolerance, Physical Dependence & Addiction

Resources for Pain Management: Understanding Tolerance, Physical Dependence and Addiction

The use of strong pain medication, particularly opioids, often carries the stigma of drug addiction and abuse. As a result, many healthcare professionals prescribe opioids conservatively for pain management and many patients and their families are just as cautious about starting opioid medications. In many ways, this harmful stigma can be attributed to a lack of understanding about addiction and its related areas, such as pharmacologic tolerance and physical dependence - none of which are the same. By understanding the key differences between these terms, people affected by pain and their healthcare professionals can feel and communicate better about the pain management treatment choices they make.

• Tolerance is a biological state of adaptation in which exposure to a drug induces changes that result in a reduction of one or more of the drug's effects over time.
• Physical dependence is a biological state of adaptation that is manifested by a drug class-specific syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist.
• Addiction is a primary, chronic, neurobiological disease with genetic, psychosocial, and environmental factors influencing its development and manifestation. It is characterized by behaviors that include one or more of the following: impaired control over drug use, continued use despite harm, and craving.

The American Academy of Pain Medicine, American Pain Society and American Society of Addiction Medicine explain the differences between tolerance, dependence and addiction as follows:

Tolerance refers to the situation in which a drug becomes less effective over time and an increased dosage of the medication is required to maintain the same pain relief. This isn't always the case. Some people with persistent pain can stay on the same dose of opioid for a long time and not develop a tolerance. Many times, if a person needs a larger dose of a drug, it's because their pain is worse or the problem causing their pain has changed.

Physical dependence means that a person will develop symptoms and signs of withdrawal (e.g., sweating, rapid heart rate, nausea, diarrhea, goosebumps, anxiety) if the drug is suddenly stopped or the dose is lowered too quickly. This does NOT mean you are addicted. In fact, many non-addictive drugs can produce physical dependence. Physical dependence is considered a normal response for those patients who are being treated over several days or on a regular basis with opioids.

To prevent withdrawal, the dose of medication must be decreased slowly and your physician may choose to do this through a process known as titration. If you believe that you no longer need to take the opioid medication or want to reduce the dose, it is essential to speak to your healthcare professional. They will guide you on how to decrease your dose over time to prevent the experience of withdrawal.

Addiction to a medication means a person has lost control over the use of the drug and they continue to use it despite harmful consequences. The term addiction now refers to a medical diagnosis and is defined as a primary, chronic, neurobiological disease with genetic, psychosocial, and environmental factors influencing its development and expression. It is characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use, continued use despite harm, and craving.

A related term is pseudoaddiction, which refers to patient behaviors that may occur when pain is under-treated. This includes an increased focus on obtaining medications ("drug seeking" or "clock watching") and even illicit drug use or deception. Pseudoaddiction is different from true addiction because such behaviors can be resolved with effective pain management.

How can an individual tell if they are becoming addicted? How can a healthcare professional determine if their patient is developing an addiction? Here are some warning signs:

• Taking more pain medication than prescribed
• Requesting prescriptions from multiple doctors
• Using alcohol or other medications to increase the effects of the pain medication
• Taking pain medication to deal with other problems, such as anxiety or stress
• Friends or loved ones expressing concern about use of pain medication

It is important to become more familiar with the relationships between pain management and addiction, tolerance and physical dependence. Knowing the difference between these terms can prevent misunderstandings about pain management. With a better understanding, individuals with pain, their families, friends, and healthcare professionals can improve how they talk, listen and act about pain.

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