Monday, October 3, 2011

Doctor Doses: Tolerance To Dependence To Addiction



According to the 2008 U.S. National Survey on Drug Use and Health, 
an estimated 1.3 million people aged 18 or older 
were dependent on pain relievers or heroin. 
(SAMHSA, Office of Applied Studies, 2008)

The number of deaths from prescription painkillers -- opioids, such as OxyContin, Vicodin and hydrocodone -- in the United States has now surpassed that of skin cancer, alcoholic liver disease and HIV, according to a new study published online in the British Medical Journal. (Irfan Dhalla et al., "Facing Up To the Prescription Opioid Crisis," British Medical Journal, August 1 2011)

The deaths may be linked with an increase in doctors prescribing the drugs to patients with chronic pain -- like osteoarthritis -- and not just cancer patients, according to Dhalla and the other University of Toronto researchers.

Between 1999 and 2007, the number of deaths associated with opioid analgesics increased from 4,041 to 14,459, the researchers also reported.

Another study, published this year in the Journal of the American Medical Association, also acknowledged the increase, and pointed out that overdose deaths were most common among patients prescribed high doses of opioids. (AS Bohnert et al., "Association Between Opioid Prescribing Patterns and Opioid Overdose-related Deaths," Journal of the American Medical Association, April 6 2011)

Tara Gomes, a researcher and epidemiologist at Ontario's Institute for Clinical Evaluative Sciences, reports a recent study (2011) shows that "about a third of people who are receiving prescriptions for long-acting oxycodone are in fact receiving doses that are considered to be high or very high dose, based on published clinical guidelines.” (Anne-Marie Tobin, "High Doses, Frequency of Opioid Prescribing Are 'Troubling': Ontario Study," The Canadian Press, January 25 2011)

What Is Considered "A High Dose?

"How high of a cliff do I have to jump off of before the fall will actually kill me?" 

Consider the above as an analogy with opiates. Doesn't the answer vary depending on the person, the cliff, the area, and many other factors? Many things may also contribute to opiate overdose.

Opiates work on the part of the brain that controls breathing. An overdose of any of them can cause a user to stop breathing. If the user is alone at the time, he or she could die of suffocation. The inability to breathe is one of the leading causes of death in oxycodone overdose cases.  

Some drugs need to "build up" in the body before the user suffers a fatal overdose. That is not the case with opiates. They can be fatal with the first use, or at any time. Even people with a high tolerance for oxycodone can experience breathing problems if they take the medicine improperly. Abusers run a high risk of fatal breathing problems each time they mishandle a pill. (http://www.enotes.com, 2011)

Tolerance, Dependence, and Addiction

Tolerance and dependence are normal physiological consequences of extended opioid therapy. In its model guidelines on the use of controlled substances for the treatment of pain, the Federation of State Medical Boards said flatly that neither physical dependence nor tolerance should be considered addiction.  (Fred Gebhart, "Doctor Shopping," http://drugtopics.modernmedicine.com, November 18 2002)

Fred Gebhart attempts to shed some light on the subject.

A. Analgesic Tolerance 

For patients with ongoing or chronic pain, a doctor may increase a dose of opioids over time as the pain worsens. The patient may also develop a tolerance to the drug and need more medicine to achieve the same results. Analgesic tolerance is the need to increase the dose of opioids to achieve the same level of analgesia. Tolerance does not equate with addiction.

B. Physical Dependence

Physical dependence is a physiological state of neuro-adaptation characterized by the emergence of a withdrawal syndrome if drug use is stopped or decreased abruptly, or if an antagonist is administered. Physical dependence does not equate with addiction. 

C. Addiction

But, repeated use of opioids, especially to get high, can lead to eventual addiction. Users will need higher and higher doses of the medicine to achieve the high. Addiction is a neurobehavioral syndrome with genetic and environmental influences that result in psychological dependence on a substance for its psychic effects. Addiction is characterized by compulsive use despite harm.

D. Pseudoaddiction

Pseudoaddiction is a pattern of drug-seeking behavior by patients who are not receiving adequate pain relief. Once adequate pain management is provided, what looks like addictive behavior disappears. 


Dangerous "Shopping" Activities Kill

"Doctor shoppers" are people who visit more than one doctor so they can get multiple prescriptions for the same medication. Fred Gebhart identified three different kinds of doctor shoppers, with three different reasons for engaging in this illegal activity:
  • Intentional Diverters are people who either feign illness or take the same illness to multiple physicians. The goal is to obtain multiple scripts, either for abuse or resale. The resale market is lucrative.
  • Accidental Shoppers simply don't know any better. They are people who see a number of different specialists for various ailments. They do not let the doctors know when they are prescribed a drug by a different physician. Accidental shoppers run the risk of having bad drug interactions or even an overdose if more than one doctor issues a prescription for pain.
  • Productive Shoppers are people who cannot get enough pain relief from one doctor. They keep going to other doctors until they receive enough medication to manage their pain. These shoppers engage in this activity because some doctors under-prescribe painkillers for people in real need of relief. Their behavior is often called pseudoaddiction, addictive-type drug-seeking activities that continue until the underlying pain is finally resolved. 
Gebhart's article: http://drugtopics.modernmedicine.com/drugtopics/article/articleDetail.jsp?id=116769

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