Pain Pills And Laxatives: A Safe Combination?

Pain medications, such as opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and antidepressants, are a common treatment for both chronic and acute pain. However, constipation is a well-known side effect, with 40-60% of non-cancer patients who take opioids experiencing opioid-induced constipation (OIC). While laxatives are often used to treat constipation, they may not be effective for OIC and can cause side effects such as abdominal symptoms, gas, bloating, and a negative impact on quality of life. It is important for patients to be educated about constipation prevention when prescribed opioids, and to consider increasing dietary fiber, fluid intake, and physical exercise to prevent constipation.

Opioid-induced constipation (OIC)

OIC can present immediately when a patient takes an opioid, or it may develop gradually during opioid therapy. Patients may also experience other gastrointestinal side effects such as nausea, vomiting, bloating, abdominal pain, and straining.

To prevent OIC, laxatives must be started at the same time as opioid medication. If OIC does develop, treatment involves both pharmacological and non-pharmacological therapies. Increasing dietary fibre, fluid intake, and physical exercise are recommended as the first line of treatment. All types of laxatives can be used, except for bulk-forming laxatives, which can make abdominal pain worse and contribute to bowel obstruction.

For refractory cases of OIC, newer agents may be used, such as methylnaltrexone, naloxegol, and naldemedine. These medications block the effects of opioids in the gut, reversing constipation.

Laxatives and stool softeners

Laxatives are products that help people empty their bowels, and there are many types. Stool softeners are a type of laxative called an emollient laxative. This means all stool softeners are laxatives, but not all laxatives are stool softeners.

Stool softeners are gentle medications with a relatively mild effect. They typically contain docusate sodium and docusate calcium as the active ingredients. They help soften the stool, making it easier to pass. Over-the-counter (OTC) stool softeners are useful when a person experiences temporary, less chronic constipation.

Stool softeners are also ideal for preventing constipation; they do not work well for established cases of constipation. They are gentle enough to prevent constipation with regular use. However, they are the least effective option for treating constipation. They are best for people with temporary constipation or mild, chronic constipation.

Healthcare professionals may prescribe stool softeners after major surgeries, such as heart surgery or hernia repair. If straining to have a bowel movement might be harmful during recovery, people can take stool softeners to avoid complications.

Laxatives, on the other hand, are used to relieve constipation. Some may be a better choice for you than others, depending on how long you need to use them and how harsh the ingredients can be on your body.

Stimulant laxatives, for example, are more appropriate for more severe symptoms. They treat more acute and chronic constipation by directly stimulating nerves in the large intestine. They work faster to bring relief but can cause side effects such as dehydration, nausea, vomiting, and abdominal cramping.

Bulk-forming laxatives, which are often derived from plants, help form a watery gel in the intestines that adds both body and lubrication to the stool. They can be used for longer periods and with little risk of side effects. They are a good option for people with chronic constipation. However, they take longer than other laxatives to work. You shouldn't use them continuously for longer than one week without talking to your doctor.

Osmotic laxatives, such as polyethylene glycol and glycerin, draw more water into your intestines. This helps to soften the stool and move it more easily. They can also be used for longer periods with little risk of side effects. They are a good option for people with chronic constipation, but they take longer than other laxatives to work. You shouldn't use them continuously for longer than one week without talking to your doctor.

Saline laxatives, such as magnesium citrate and magnesium hydroxide, draw more water into the intestine. This softens the stool and stimulates movement in your intestines to help you pass it. However, they should not be used on a regular basis. When used regularly, they can cause dehydration and electrolyte imbalances.

Stimulant laxatives, such as bisacodyl and sennosides, stimulate and increase the movement of your intestines. They also should not be used on a regular basis. Regular use can cause dehydration and electrolyte imbalances.

Diet and lifestyle changes

Diet Changes

• Increase your fiber intake: Fiber is essential for promoting regular bowel movements and relieving constipation. Aim for 22 to 34 grams of fiber per day for adults, depending on your age and sex. Good sources of fiber include whole grains, legumes, fruits, vegetables, and nuts.
• Consume high-fiber fruits and vegetables: These include apples, pears, grapes, kiwifruit, blackberries, raspberries, broccoli, and beans.
• Probiotics: Probiotics are beneficial bacteria that improve gut health and soften stools. Yogurt, kefir, and sauerkraut are excellent sources of probiotics.
• Olive and flaxseed oils: These oils may have a mild laxative effect and can help improve digestion.
• Drink plenty of liquids: Water and other liquids, such as fruit and vegetable juices, help the fiber work effectively in your body. Staying hydrated is crucial for overall health and can help prevent constipation.
• Avoid low-fiber foods: Stay away from processed and frozen meals, hot dogs, and microwavable dinners, as they tend to have little to no fiber.

Lifestyle Changes

• Regular exercise: Physical activity is essential for encouraging bowel movements. Even moderate increases in physical activity can be beneficial for constipation.
• Establish a routine: Try to maintain a consistent daily schedule for bowel movements, such as setting aside time each day after breakfast. Respond to the urge to defecate immediately.
• Limit intake of constipating foods and medications: Reduce your consumption of processed grains, dairy products, fried foods, and medications that can cause or worsen constipation.

Rectal suppositories and enemas

Suppositories are solid cones designed to be inserted into the rectum, where they dissolve. They are commonly used to treat constipation and are also effective for treating nausea and vomiting. They can also be used to administer medications for conditions such as haemorrhoids and rectal pain.

Enemas, on the other hand, involve injecting fluid directly into the rectum to stimulate a bowel movement. They are commonly used for constipation relief, treating faecal impaction, and preparing for surgery or a colonoscopy. Enema solutions vary, including sodium phosphate, glycerin, and mineral oil. It is important to follow the instructions carefully to avoid unpleasant side effects and potential damage to the colon.

Both suppositories and enemas can be administered at home or in a healthcare setting. It is important to prioritise patient comfort and privacy during the procedure.

Drugs for opioid constipation

Opioid-induced constipation (OIC) is a common side effect of opioid pain medication, affecting 40-60% of patients without cancer who are receiving opioids. It is caused by opioid drugs inhibiting gastric emptying and peristalsis in the gastrointestinal tract, resulting in delayed absorption of medications and increased absorption of fluid, which leads to hardened stools and constipation.

To prevent OIC, laxatives must be started at the same time as opioid therapy. All types of laxatives can be used as initial therapy except for bulk-forming laxatives, which should be avoided. Bulk-forming laxatives increase the bulk of stools and can worsen abdominal pain and contribute to bowel obstruction.

The most common treatment for OIC is a stimulant (senna/bisacodyl) with or without a stool softener (docusate), or the daily administration of an osmotic laxative (polyethylene glycol). Stool softeners are ideal for preventing constipation but are less effective once constipation is established.

For more difficult cases of OIC, newer agents may be used, with methylnaltrexone being the most superior. Methylnaltrexone bromide (Relistor) is the first available peripherally acting opiate antagonist used to treat OIC. It does not cross the blood-brain barrier, so it does not induce symptoms of opioid withdrawal. It has been found to be significantly better at reversing OIC than lubiprostone, naloxegol, and oral methylnaltrexone. However, Relistor should not be used in patients with peptic ulcer disease, diverticulosis, colon cancer, or obstruction.

Lubiprostone (Amitiza) is a type-2 chloride channel activator that increases fluid secretion in the gastrointestinal tract, resulting in increased tone, enhanced peristalsis, and accelerated small bowel and colonic transit times. Lubiprostone can increase the overall frequency of bowel movements each week in patients with OIC. It is approved for the treatment of OIC in patients with non-cancer pain and cancer.

Other prescription medications for the treatment of OIC include naloxegol (Movantik) and naldemedine (Symproic). These medications block the effects of opioids in the gut and help stools pass more easily.

Frequently asked questions