Treating Opioid-Induced Constipation in Older Adults

In adults older than 60 years, chronic constipation is common and can often be treated with lifestyle alterations such as increasing fluid and fiber intake or scheduled toileting after meals.¹ While constipation is not a physiologic consequence of normal aging, comorbid medical conditions, dehydration, and decreased mobility contribute to increased prevalence in older adults.² Determining whether a patient is experiencing primary or secondary constipation symptoms is one of the first steps in deciding on appropriate treatments and interventions. 

Treatment for constipation due to secondary causes, such as concurrent medical conditions including metabolic diseases, myopathic conditions, neurologic diseases, or structural abnormalities can prove complex.² Another important and prevalent secondary cause of constipation is medication use, particularly drugs that affect the nervous system and nerve conduction such as opioids.² Unlike other medication side effects, opioid-induced constipation (OIC) often does not dissipate after a few days, and extended use can increase chances of constipation.³

In order to learn more about the diagnosis and treatment of OIC in older adults, Annals of Long-Term Care: Clinical Care and Aging spoke with Leah Sera, PharmD, an assistant professor in the Department of Pharmacy Practice and Science at the University of Maryland. She also maintains an active clinical practice at Medstar Montgomery Medical Center where she works with an interdisciplinary inpatient palliative medicine team. 

How prevalent is OIC in long-term care (LTC) settings? How do you anticipate deprescribing initiatives surrounding opioid use may affect the prevalence of this condition?

Overall, the prevalence of OIC in patients with chronic noncancer pain varies in published studies. In one study of LTC residents the prevalence of concurrent opioid and laxative use was 55%.⁴ Another more recent study asserts that 74% of nursing home residents are affected.⁵ Older patients and those with multiple comorbidities often have additional risk factors that may exacerbate constipation. 

Any decrease in opioid use may lead to decreased prevalence of OIC in the general population, but OIC will remain an important therapeutic issue for any patients who require opioids to manage severe cancer or noncancer pain. 

Are there certain opioids that are more likely to cause constipation? What types of conditions make a person at greater risk of experiencing OIC?

In general, different opioids will produce similar amounts of constipation when given at equianalgesic doses. There a possibility that transdermal fentanyl (a long-acting opioid formulation) may be less constipating than long-acting oral opioid formulations, but evidence is conflicting.^6-8

There are many other factors that can contribute to constipation. Medical conditions like diabetes, Parkinson’s disease, and hypothyroidism are associated with constipation. There are certainly medications other than opioids—some blood pressure medications, vitamins (like iron), and antihistamines are common culprits. 

Older adults may be particularly prone to nonmedical factors contributing to constipation—decreased oral intake (and/or a low fiber diet) and decreased mobility. Older residents may need assistance with toileting, and suppressing the urge to defecate may exacerbate constipation.

Please discuss the latest information related to diagnosing OIC. What is the process for determining the primary cause of constipation in older adults in LTC?

It’s important to consider a patient globally when determining the cause of constipation, as there may be a number of contributing factors. However, because opioids predictably cause constipation (and it’s a side effect that doesn’t go away), anyone who requires regular opioid therapy for pain should be using laxatives from the beginning; we shouldn’t wait until a patient experiences constipation to begin treatment. 

A general assessment of constipation should include current medications, baseline and current bowel habits, date and quality of last bowel movement, use of laxatives, and associated symptoms such as abdominal pain, nausea, or vomiting. 

Additionally, there is a screening tool called the Bowel Function Index that can be used to screen specficially for OIC. This screening tool consists of three questions regarding symptoms of constipation over the previous week, rated on a scale of 0 (not at all) to 100 (very strong) with higher scores indicating higher likelihood of OIC.⁹ An important note—patients with new or worsening abdominal pain, bloody stools, or unintended weight loss should be seen by a physician, because these may be indicative of other conditions.

Please outline the best management strategies for OIC and strategies for patients with comorbidities.

First-line treatments for OIC include the stimulanat laxatives (senna or bisacodyl) and osmotic agents (polyethylene glycol, lactulose, or magnesium preparations). Docusate is a stool softener commonly used to treat constipation, but its benefit in OIC has been debated, as it does not address the reduced gastrointestinal motility caused by opioids that is primarily responsible for causing constipation. Many first-line agents are inexpensive and available over-the-counter. These agents should be started concurrently with regular opioid therapy (short-acting or sustained-release) and may be titrated if initial doses are not effective. 

Other therapies include the peripherally-acting mu-opioid antagonists methylnaltrexone and naloxegol and the chloride-channel activator lubiprostone. These have all shown efficacy in patients with OIC and chronic noncancer pain, and are generally considered second line due to cost. These medications are available by prescription only.  

Rectal therapies (suppositories and enemas) are another option for treatment if oral over-the-counter therapies are not effective. Rectal therapies may be particularly useful for patients who have difficulty swallowing or are otherwise not able to take oral formulations. Enemas and suppositories may be stimulants, lubricants, or osmotic laxatives, and rectal therapies additionally stimulate the ano-colonic reflex to promote defecation. 

Nonpharmacologic therapies are unlikely to be effective on their own. Bulk-forming agents such as psyllium may actually be harmful to patients with OIC and increase the risk of bowel obstruction. 

What steps in LTC settings can be taken to avoid the occurrence and recurrences of OIC in older adults taking opioids? Which LTC workers are best positioned to combat OIC?

Residents in LTC settings will benefit from careful monitoring of bowel habits with toileting assistance as needed, continuing medication reviews to identify additional constipating medications, and promotion of appropriate oral intake and mobility. 

Nurses and nursing aides play an important role in the assessment and identification of OIC and relaying this information to prescribers. At-risk residents should be specifically asked about their bowel movements, as many residents do not think to report constipation or they simply avoid the topic.

Pharmacists may assist with medication reviews, while physical therapists and dieticians can assist in optimizing diet and mobility as appropriate.

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2. Hsieh C. Treatment of constipation in older adults. Am Fam Physician. 2005;72(11):2277-2284.

3. WebMD. How do opioid pain meds cause constipation? WebMD website.  http://www.webmd.com/pain-management/constipation-from-opioids#1.Accessed March 24, 2017. 

4. Max EK, Hernandez JJ, Sturpe DA, Zuckerman IH. Prophylaxis for opioid-induced constipation in elderly long-term care residents: a cross-sectional study of Medicare beneficiaries. Am J Geriatr Pharmacother. 2007;5(2):129-36.

5. Rao SSC, Go JT. Update on the management of constipation in the elderly: new treatment options. Clin Interv Aging. 2010;5:163-171.

6. Ackerman S, Knight T, Schein J, Carter C, Staats P. Risk of constipation in patients prescribed fentanyl transdermal system or oxycodone hydrochloride controlled release in a California Medicaid population. Consult Pharm. 2004;19(2):118-32.

7. Wirz S, Wittmann M, Schenk M, et al. Gastrointestinal symptoms under opioid therapy: a prospective comparison of oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine. Eur J Pain. 2009;13(7):737-743. 

8. Radbruch L, Sabatowski R, Loick G, et al. Constipation and the use of laxatives: a comparison between transdermal fentanyl and oral morphine. Palliat Med. 2000;14(2):111-119.

9. Ducrotte P, Causse C. The Bowel Function Index: a new validated scale for assessing opioid-induced constipation. Curr Med Res Opin. 2012;28(3):457-466.