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What You Should Know About This Uncomfortable Opioid Side Effect

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Editor's Note

Please see a doctor before starting or stopping a medication.

For many of us, chronic illness also means chronic pain. While pain can be managed to varying degrees of success with opioids, these vital medications come with their own set of side effects. One of the most common — and in my experience, debilitating — side effects is opiate-induced constipation (“OIC”).

Opioids depress the central nervous system (“CNS”), blocking pain receptors, which in turn reduces the brain’s interpretation of pain. In doing this, they also slow down other functions that are managed by the CNS. These are generally involuntary movements — like breathing and the movement of
the intestines.

Here’s How It Works

Health officials have focused on the fact that slowing down the body’s drive to breathe can be fatal. But slowing down the body’s ability to move waste out can cause a host of really bad symptoms. Normally, the intestines move in a constant squeezing and releasing motion, called “peristalsis,” pushing the food through the system. During this trip, the intestinal walls allow absorption of nutrients — and reabsorption of water into the blood stream.

The longer this cargo remains in the intestines, the more water is reabsorbed. This results in stools becoming very stiff and hard. So, even when the bowel begins moving again, it’s very difficult to push that load through. This is constipation.

More Than Just Uncomfortable

Opioids make it difficult for the food to move out of the stomach, through the pylorus and into the first part of the small intestine, called the “duodenum.” This often causes decreased appetite, and even nausea and vomiting. When the food moves through the intestine so slowly, it causes cramps, gas pain and bloating.

While being constipated can be miserable in itself, this can cause other problems, many of which require medical intervention. These include:

  • Hemorrhoids (swollen veins in the anus)
  • Tears in the anus
  • Rectal prolapse (the end of the rectum pokes out through the anus)

What’s a Body to Do?

Fortunately, there are steps we can take to prevent and relieve the worst symptoms of constipation. Because the bowel is sucking all of the moisture out of the cargo, the first step is to drink lots and lots of water. Every. Day.

While it’s good to drink down large glasses or bottles of water when you can, most people find it easier to drink throughout the day. Keeping a water bottle at hand — whether commercially bottled or in a sports cup — is the first step. This allows you to sip constantly. Some find it helpful to remind themselves to take two large drinks when they raise the bottle to take a sip — it’s easy, and will greatly increase the water content of the intestine.

About Laxatives

There are six different types of laxatives, each of which works differently to move the cargo through the intestinal tract.

1. Emollient Laxative: These are known as “stool softeners,” and contain either docusate sodium or docusate calcium. These medications help keep more water in the bowel, making the cargo softer and easier to push along. Many doctors recommend that their patients take a stool softener every day while they are taking opiate medications. Used alone, however, these are ineffective in solving opiate-induced constipation.

2Bulk-Forming Laxative: This is a fancy term that refers to fiber laxatives (such as Metamucil, FiberCon, and Citrucel) and the newer Polyethylene Glycol (such as MiraLAX). Both of these types add bulk that both holds water in the stool, and pushes the cargo through the tunnel. These laxatives are safer to use for a longer period of time, which makes them a good option for people with OIC.

3. Lubricant Laxative: This is a mineral oil that coats the cargo and the intestines. This helps prevent loss of so much water, and greases the tracks to help the cargo move through more easily. There is a drawback to using mineral oil on a regular basis, however. It can prevent your body from absorbing vital fat-soluble vitamins, including vitamins A, D, E, and K.

4Hyperosmotic Laxative: These laxatives contain polyethylene glycol and glycerin. Rather than simply decreasing the amount of water that is sucked out of the intestinal tract, these substances actually pull more water into the intestines — it’s definitely a two-way route! Like bulk-forming laxatives, hyperosmotics can generally be used longer-term without negative side effects, though it’s always important to talk to your doctor about use for longer than a week.

5. Saline Laxative: With the active ingredients of magnesium citrate and magnesium hydroxide, these laxatives also draw more water into the intestinal tract. They also stimulate the intestines to move in order to push the cargo through. The most commonly known saline laxatives include Fleet and Milk of Magnesia. Regular use of these preparations can cause dehydration and electrolyte imbalance, which can be serious.

6. Stimulant Laxative: These contain either bisacodyl or sennosides, which stimulate – or irritate – the nerves in the intestines, causing them to move faster. These include popular brands like Senokot, Dulcolax, ex•lax and Colace. If used on a regular basis, stimulant laxatives can cause you to become dehydrated and to have imbalances in your electrolytes. They also may eventually require higher and higher doses in order to achieve the desired effect.

This is helpful information to get you started, but you should really talk to your doctor about what treatment for opiate-induced constipation is right for you.

The Bottom Line

Constipation is an ugly fact of life for those of us who depend on opiates to control chronic pain. This is not something to keep hidden. Rather, it’s an important thing to discuss with your doctor, who may recommend over-the counter preparations, at least to begin with.

There are other treatments, however, in the form of prescription medications. These medications prevent the opiate medications from attaching to the opiate receptors in the intestine, while not affecting their attachment to pain receptors in the brain.

It’s time to stop the additional struggling that OIC causes… it’s time for us to have those important conversations with our doctors!

Getty image via spukkato

Originally published: September 29, 2019
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