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8 medications that cause constipation

Opioids, NSAIDs, antihistamines, tricyclic antidepressants, urinary incontinence medications, iron, blood pressure meds, and anti-nausea medicine are medications that may cause constipation
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By | Updated on Apr. 7, 2023 Medically reviewed by Karen Berger, Pharm.D.
Toliet paper roll: Medications that cause constipation

Key takeaways

  • Opioids, NSAIDs, antihistamines, tricyclic antidepressants, urinary incontinence medications, iron supplements, blood pressure medications, and anti-nausea medicines may cause constipation.

  • Constipation symptoms include fewer than three bowel movements per week, small hard stools, excessive straining, and potential abdominal pain and nausea.

  • Medication-induced constipation can lead to serious complications such as hemorrhoids, rectal bleeding, and fecal impaction, highlighting the importance of seeking medical advice for treatment.

  • Preventive measures for medication-induced constipation include staying hydrated, eating a high-fiber diet, and exercising regularly. Listen to your natural bowel movement urges to establish a regular bowel habit.

Constipation symptoms and causes | Medications that cause constipation | Constipation treatment | How to prevent constipation

Constipation is a common condition. Around 16% of people in the United States and one-third of older adults over the age of 60 complain of chronic constipation. Between 2006 and 2011, constipation accounted for more than 700,000 trips to the emergency room. 

Symptoms and causes of constipation

Symptoms of constipation include:

  • Fewer than three bowel movements per week
  • Small, hard, dry stools that are difficult or painful to pass
  • The need to strain excessively to have a bowel movement

Some people experience pain in their abdomen when they are constipated, especially after meals. Some might have nausea, vomiting, headaches, or a general feeling of being unwell. 

There are many causes of constipation, including:

  • A low-fiber diet (especially diets high in meat, milk, or cheese)
  • Dehydration
  • Sedentary lifestyle
  • Ignoring or delaying the urge to defecate
  • Travel and schedule changes
  • Laxative overuse
  • Pain or discomfort around the anus
  • Colorectal cancer
  • Pregnancy
  • Medical conditions, including irritable bowel syndrome, diverticulosis, hypothyroidism, high blood calcium levels, multiple sclerosis, Parkinson’s disease, and spinal cord injury

RELATED: What you need to know about constipation after surgery

Drug-induced constipation

Constipation can also be a side effect of some medications. “Medication-induced constipation is extremely common these days,” according to Bryan Curtin, MD, the Director of Neurogastroenterology and Motility, at Mercy Medical Center. “People take more medications than ever before, and because most medications have an extensive profile, prescribing doctors tend to ignore constipation as a significant side effect when compared to more serious ones. It is not uncommon for people to be on as many as four or five medications that might be exacerbating constipation, and this isn’t even including opioids, which can be absolutely devastating to the GI tract.”

Constipation can be uncomfortable, but it can also lead to complications such as:

  • Hemorrhoids
  • Rectal bleeding
  • Anal fissures
  • Rectal prolapse
  • Fecal impaction

“When conservative measures, such as changes to the diet, increased hydration, and over-the-counter laxatives have failed, patients should be seen by a primary care doctor or gastroenterologist,” says Dr. Curtin. “This is true, especially if the constipation is accompanied by other significant symptoms, such as nausea, abdominal pain, or unexpected weight loss.”

8 medications that cause constipation

  1. Opioid pain relievers
  2. Nonsteroidal anti-inflammatory drugs (NSAIDs)
  3. Antihistamines
  4. Tricyclic antidepressants
  5. Urinary incontinence medications
  6. Iron supplements 
  7. Blood pressure medications
  8. Anti-nausea medicines

1. Opioid pain relievers

Also called narcotics, opioids treat pain that is severe and that has not improved with other, milder pain medications. They are effective at relieving pain, but can be habit-forming and have a high rate of abuse. Only use opioid medications under the direct care of a health professional. Commonly prescribed opioid pain medications include:

Many patients on opioids for chronic pain relief experience opioid-induced constipation (OIC.) It is considered the most prominent digestive problem and one of the most common side effects of opioids. It can be disabling and is a common reason for people to stop taking the medications, according to a report published in 2019. Ask your doctor if you can start a laxative at the same time as the opioid.

2. NSAIDs

NSAIDs are the most prescribed medications for treating conditions such as arthritis, according to the American Academy of Orthopedic Surgeons. They are also used to reduce fever, inflammation, and mild to moderate pain. This class of medications includes:

3. Antihistamines

Antihistamines reduce symptoms of allergies. When you are allergic to something, your body releases histamines that cause congestion, runny nose, sneezing, itching, swelling of the nasal passages, hives, skin rashes, or itchy and runny eyes. Common over-the-counter (OTC) antihistamines include:

4. Tricyclic antidepressants

Tricyclic antidepressants are a class of medication used to treat depression. They work by increasing levels of norepinephrine and serotonin and blocking the action of acetylcholine. By balancing these three neurotransmitters, tricyclic antidepressants alleviate depression. There are newer medications for depression with fewer adverse effects; however, these tricyclic antidepressants work better for some people. Some common brands include:

  • Tofranil (imipramine)
  • Vivactil (protriptyline)
  • Elavil (amitriptyline)
  • Pamelor (nortriptyline)

5. Urinary incontinence medications

Urinary incontinence medications treat overactive bladder and other conditions that can cause bladder leakage or frequent urination. This condition is more common in women than in men; however, it can occur in men as well. It is one of the most common conditions seen in primary care practice, according to the American Academy of Family Physicians. 

These medications work by either reducing bladder spasms or relaxing the bladder wall muscle, allowing it to hold more urine and empty more fully. Some of the most frequently prescribed urinary incontinence medications include:

6. Iron supplements

Iron supplements treat anemia and iron deficiency. They are available over the counter. Frequently used forms of iron in supplements include:

7. Blood pressure medications

There are two types of blood pressure medicines that most commonly cause constipation: calcium channel blockers and beta blockers. Calcium channel blockers work by dilating arteries, which reduces the effort your heart must exert to pump blood. Beta-blockers work by slowing down your heart rate, lowering your blood pressure.

Calcium channel blockers include:

  • Norvasc (amlodipine)
  • Plendil (felodipine)
  • Cardene (nicardipine)
  • Adalat CC, Procardia XL (nifedipine)
  • Cardizem, Tiazac, Dilt-XR (diltiazem)

Common beta blockers include:

8. Anti-nausea medications

Also called anti-emetics, anti-nausea medications block different pathways in your body that trigger nausea and vomiting. These include: 

Common medications used to treat nausea include:

How to treat constipation caused by medication

In addition to lifestyle changes, there are over-the-counter laxatives and prescription medicines to relieve constipation. As with any medication, it’s important to seek the professional medical advice of a doctor or pharmacist before using laxatives. Always read the medication guide before using any of the following products.

RELATED: How to treat constipation naturally

Over-the-counter laxatives

Fiber-based laxatives, also called bulk-forming laxatives, increase water in your stools to make them softer. Common fiber-based laxatives include:

RELATED: Benefiber vs. Metamucil

Stool softeners, also called emollient laxatives, add moisture to your stools to make it easier to pass them. Commonly used stool softeners include:

Stimulant laxatives work by stimulating nerves in your digestive tract, triggering the muscles in your large intestine to contract, pushing your stool through. Commonly used stimulant laxatives include:

Osmotic laxatives pull water from surrounding tissue into your digestive tract to make it easier for the stool to pass through the intestine. Commonly used osmotic laxatives include:

Prescription medicine for constipation

For many people, making lifestyle changes and using over-the-counter laxatives will help relieve constipation. Everyone’s bowel habits are different though. You may be used to having one—or more—bowel movements a day or one every few days. Doctors typically define constipation as three or fewer bowel movements per week. In the case of constipation or chronic constipation, healthcare providers may prescribe one of the following prescription drugs:

Prescription drugs for opioid-induced constipation include:

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How to prevent medication-induced constipation

Not everyone will become constipated when using these medications. However, you should be aware of the potential side effects and what you can do to prevent constipation due to medication. 

“In general, you want to make sure you are well hydrated with water, not coffee or carbonated beverages,” says Dr. Curtin. “You also want to have a healthy amount of fiber in your diet and try to limit processed foods. It is worth asking your doctor if there are alternative agents. Calcium channel blockers, used for high blood pressure, such as diltiazem, for example, are notorious for causing constipation. If there is another class of medication that can treat the underlying health problem, you should at least be given the option.”

Fortunately, there are some relatively simple nonpharmacologic approaches to preventing constipation.

Eat a high-fiber diet

Include high-fiber foods in your diet. These include:

  • Legumes: Lentils, kidney beans, split peas, chickpeas, black beans, lima beans
  • Vegetables: Carrots, beets, broccoli, artichokes, brussels sprouts, kale, spinach, tomatoes 
  • Fruits: Apples, prunes, pears, strawberries, avocado, raspberries, bananas 
  • Grains: Quinoa, oats, popcorn, any other whole grains
  • Nuts and seeds: Almonds, chia seeds, coconut, pistachios, walnuts, sunflower seeds, pumpkin seeds
  • Other foods: Sweet potatoes, dark chocolate (cocoa content of 70% to 95% or higher)

If your diet is low in fiber, you can also talk to your doctor about adding a fiber supplement. 

Drink enough fluids

Water plays a large part in keeping your body healthy. It is essential for keeping fecal matter flowing through the intestines. Although most people have heard that you should drink six to eight glasses of water a day, you might not need to consume that much. Four to six cups of water per day are generally enough for healthy people, according to Harvard Health. 

Some medications cause you to retain water, and some health conditions require you to limit your fluid intake. If you are taking medications that cause constipation, you should talk to your doctor about how much water you should be drinking.

Exercise regularly

Physical activity can decrease the time it takes food to move through the large intestine. Aerobic exercise accelerates breathing and heart rate, which stimulates the natural contraction of the intestinal muscles, moving stools out of the intestine quickly. 

Listen to your body

Your body naturally tells you when it is time to have a bowel movement. Some people try to hold it until they are at home or in a bathroom by themselves. Ignoring the urge can cause constipation, according to the National Institute on Aging. 

Establish regular bowel habits

Bowel retraining is one way to establish a routine. The best time for a bowel movement is 20 to 40 minutes after a meal. Attempt to have a bowel movement every day at the same time. Digital stimulation may help. Use this method every day until you establish a routine.