What is narcotic bowel syndrome?

Narcotic bowel syndrome or opioid bowel dysfunction presents itself as worsening abdominal pain which could be chronic or recurrent. In fact, this pain is the result of opioid therapy, it aggravates by prolonged and increasing narcotics dosage. To illustrate, an important number of adults experience long-lasting pain, resulting in bad life quality, less productivity and frequent medication need. Opioid is a popular drug that is commonly prescribed for pain caused by diseases such as cancer or non-cancer ones. However, in addition to side effects such as constipation, sedation, itching and respiratory depression, narcotic bowel syndrome is a less-likely side effect.

Causes of narcotic bowel syndrome:

NBS is not understood completely, but about 6% of chronic opioid users report feeling hyperalgesia (an elevated feeling of pain and a hypersensitive response to it). In other words,  there's no accurate estimate of the incidence of narcotic bowel syndrome, but according to case reports, about 4-6% of people who use long-term opioids develops the syndrome. The clinical management of NBS is gradual opioid cessation as well as controlling the symptoms resulting by clonidine, antidepressants and benzodiazeoines. Besides, it's good to receive psycoscial treatment to avoid relapse. In addition, laxatives and opiod antagonists are suitable for constipation prevention.

Symptoms of narcotic bowel syndrome:

Obviously, people take opoids to reduce pain, so the pain resulting from opoids tends to be unnoticeable. Therefore, the patient ends up taking more opioids to stop the pain which worsens the situation and leads to severe abdominal pain. On contrary to the usual side effects of opinoids including constipation, nausea, vomiting, abdominal cramps and bloating, abdominal pain resulting from NBS is different. Althought narcotic bowel syndrome pain might come along with the side effects if opioids.

Risk factors:

narcotic bowel syndrome is not more prevalent in any specific population, but studies suggest that the following sub-populations are more susceptible:

• Females are at a higher risk than males.
• Being unemplyed or unable to work for a long time because of health problems.
• People having moderate to severe pains.
• Psychosocially impaired individuals such as those suffering from anxiety, depression, anger, impulsive behaviors, etc...

How to diagnose narcotic bowel syndrome?

Narcotic bowel syndrome diagnosis is challenging since people are often unfamiliar with such condition. Hence, establishing a link between opioids usage and the worsening abdominal pain is a necessity.

History:

Have you went through these events, it makes it clearer to rule out NDS.

• Having a pain that continues to increase despite using a higher doses of opioids.
• 3 months of opioids usage.
• Abdominal pain starts 14 to 28 days after taking opioids.
• A daily dose of morphine or a comparable opioid of 50-75 mg daily.
• Burning-colicky abdominal pain.
• Experiencing opoids side effects including nausea, vomiting, constipation and abdominal craps.
• Anorexia and weight loss.
• Pain increase when eating.

Chest x-ray:

As a result of opioid-induced constipation, it's possible to notice partial bowel obstruction or ileus and fecal impaction.

Narcotic bowel syndrome treatment:

• Opioids withdrawal: This is the key step to treat NBS is to stop opioids gradually which requires pain management medication and therapies such as antidepressants and psychological support. Indeed, withdrawing the opioid slowly for days or weeks means dealing with the after effect of withdrawal as well as finding an alternative pain relief methods. In short, once NBS is diagnosed, a long-acting pain killer such as methadone is prescribed. Following that, withdrawal symptoms are avoided by clonidine, duloxetine and lorazepam.
• Antidepressants: The usual treatment of NBS are antidepressant drugs. The tricyclic antidepressant's peak therapeutic effect is seen after few weeks of starting the drug, so opioids should not be weaned or stopped before starting on antidepressants. These drugs increases patients pain tolerance as well as enhance mood and general well-being of a patient. The main challenge with using antidepressants is them not working the same for all patients with NBS. Besides, since their therapeutic effects take time to show, it delays the determination if the drug is working or not.
• Benzodiazepines: These include clonazepan and lorazepam which can be taken orally or intravenously. As a matter of fact, their anti-anxiolytic features induces calmness but it has to be diacontinuous to prevent dependancy.
• Clonidine: Their anti-anxiolytic properties helps with chills, muscle pain and uneasiness. Furthermore, it also helps prevent hyperalgesia.
• Mood stabilizers or anti-psychotics: These are the last resort if the previous ones aren't effective.
• Behavioral therapy: There should always be trust and complete understanding between the patient and healthcare provider. Moreover, hypnosis reduces NBS pain by targeting the parasympathetic nervesm
• Constipation control: Laxatives are effective in avoiding constipation so giving them along opioids is important. Finally, the patients may get positive results if they exercise and drink enough water.

References:

-Kong EL, Burns B. Narcotic Bowel Syndrome. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493207/

-Grunkemeier DM, Cassara JE, Dalton CB, Drossman DA. The narcotic bowel syndrome: clinical features, pathophysiology, and management. Clin Gastroenterol Hepatol. 2007;5(10):1126-1122. doi:10.1016/j.cgh.2007.06.013

-Image credits: https://www.freepik.com/vectors/large-intestine