Amitiza side effects and how to avoid them

Amitiza is an FDA-approved brand-name medication manufactured by Takeda Pharmaceuticals. It is classified as a laxative and is used for the treatment of chronic idiopathic constipation (CIC) in adults. It is also used to treat constipation from various other causes in adults. While Amitiza is generally well tolerated, there are some potential side effects that people should be aware of. The most common side effects of Amitiza include diarrhea and abdominal pain. Less common, but more serious side effects, can include low blood pressure.

Learn more about the side effects of Amitiza and what you can do to avoid them.

What is Amitiza (lubiprostone)?

Amitiza (lubiprostone) is a chloride channel activator that is used to increase fluid secretion in your intestines to soften your stool, increase gastrointestinal motility, and encourage spontaneous bowel movements (SBM). Amitiza is approved by the U.S. Food and Drug Administration (FDA) to treat the following conditions in adults:

  • Chronic idiopathic constipation (CIC)
  • Opioid-induced constipation (OIC) in patients taking opioid drugs for chronic non-cancer pain. The effectiveness of Amitiza in the treatment of OIC in patients taking Dolophine (methadone) has not been established
  • Irritable bowel syndrome with constipation (IBS-C) in women ≥18 years old

The safety and efficacy of Amitiza have not been established in pediatric patients under the age of 18.

Lubiprostone is a fatty acid derived from prostaglandin E1 that activates the CIC-2 chloride channels in your gastrointestinal epithelial cells. By activating the CIC-2 channels, lubiprostone increases the secretion of chloride-rich fluid in your intestines without affecting your serum electrolyte concentrations. Increasing fluid secretion helps improve GI motility and promote spontaneous bowel movements (SBM). In clinical studies, this reduced symptoms such as bloating, abdominal discomfort, and straining within 1 week.

Is Amitiza for chronic constipation?

Amitiza is for the treatment of chronic idiopathic constipation and constipation-predominant irritable bowel syndrome and postoperative ileus.

What are the benefits of Amitiza?

Amitiza helps to improve symptoms such as abdominal discomfort, bloating, stool texture, reducing strain, and the feeling of not completely relieving yourself.

How long does it take for Amitiza to work?

Around 60% of patients have a bowel movement within 24 hours of taking Amitiza and 80% have a bowel movement within 48 hours. This was at a significantly higher rate when compared to the placebo.

What are the most common side effects of Amitiza?

The most common possible side effects of Amitiza include the following:

  • Nausea
  • Diarrhea
  • Headache
  • Abdominal pain
  • Abdominal distension
  • Flatulence
  • Vomiting
  • Loose stools
  • Lightheadedness and dizziness
  • Fatigue
  • Dry mouth

Amitiza can cause serious adverse events, including:

  • Hypersensitivity reactions including hives, angioedema, and trouble breathing
  • Severe diarrhea
  • Low blood pressure and fainting
  • Shortness of breath
  • Chest tightness or pain

This is not a complete list of the possible side effects of Amitiza. Contact your healthcare provider for medical advice about any serious side effects you experience while taking Amitiza. You can report your side effects to the FDA at 1-800-FDA-1088 or

Does Amitiza cause weight loss?

Weight loss or weight gain are not side effects of taking Amitiza. If you experience changes in weight while taking this medication, speak to your doctor for medical advice.

Does Amitiza cause hair loss?

Hair loss has been reported in females over the age of 60 who have been taking Amitiza for less than 1 month.

Does Amitiza make you tired?

Tiredness is a common side effect of Amitiza. Speak to your doctor if this side effect worsens.

Amitiza dosage

Amitiza is available as an oval, soft gelatin capsule containing 8 mcg or 24 mcg of lubiprostone with “SPI” printed on one side.

Take Amitiza exactly as your healthcare professional prescribes it to you. Do not change your dose or stop taking Amitiza without discussing it with them. Amitiza is typically taken twice daily. Taking Amitiza with food and water can help reduce the risk of nausea. You should swallow the Amitiza capsules whole. Do not break, crush, or chew Amitiza capsules. Store Amitiza at room temperature between 15°C-30°C (59°F-86°F) away from light and extreme temperatures.

You are advised to read the medication guide provided with this medicine for drug information and patient information. Always speak with your healthcare provider for medical advice about any changes to your dose so they can monitor and evaluate your condition.

What is the maximum amount of Amitiza to be taken in a day?

The maximum dose is 48 mcg per day.

What should you do if you miss a dose of Amitiza?

If you forget to take a dose of Amitiza, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take your next dose and your normal scheduled time. Do not take extra doses to make up for a missed dose.

What time of day should Amitiza be taken?

Amitiza is taken either once in the morning and once in the evening or once daily. Your healthcare provider will tell you how to take it.

Amitiza drug interactions

When Amitiza is taken with other drugs, it may change the way they work or increase the frequency and severity of side effects. Make sure your doctor is aware of all prescription drugs, over-the-counter medications, vitamins, and herbal supplements you take.

Amitiza warnings & precautions

Don’t take Amitiza if you:

  • Have had an allergic reaction to Amitiza or any of its inactive ingredients in the past
  • Have known bowel obstruction

Talk to your doctor before taking Amitiza if you:

  • Have liver disease
  • Have an abdominal obstruction or blockage
  • Have severe diarrhea
  • Are pregnant, plan on becoming pregnant
  • Are breastfeeding or plan to breastfeed

You should always check with your doctor or pharmacist before taking any medication, including Amitiza, to make sure it is safe for you.

Can I drink alcohol while taking Amitiza?

Alcohol consumption is safe in moderation and is not known to interact with Amitiza. Alcohol may, however, increase side effects such as nausea and dizziness.

How to avoid Amitiza side effects

The best way to avoid side effects is to take Amitiza as directed by your doctor. Follow your doctor’s instructions carefully, and do not take more or less than prescribed.

If you experience any side effects, talk to your doctor or pharmacist. They may be able to recommend ways to help reduce or prevent some of the side effects.

1. Stick to the recommended dosage

Take your prescribed dose of Amitiza that has been recommended by your healthcare professional. Do not take more or less than prescribed.

2. Monitor your blood sugar levels

If you have diabetes, it is important to monitor your blood sugar levels closely while taking Amitiza. Check your blood sugar levels as directed by your doctor and report any changes to your doctor immediately.

3. Drink plenty of fluids

Drink eight to 10 glasses of water or fluids every day to help prevent dehydration, which can make side effects worse.

4. Don’t skip meals

Eating regular meals and snacks will help to prevent low blood sugar levels (hypoglycemia).

5. Check your feet

If you have diabetes, check your feet regularly for any cuts, sores, or redness. Tell your doctor if you experience any problems with your feet while taking Amitiza.

6. Know the signs and symptoms of Amitiza side effects

Signs and symptoms of side effects include diarrhea and flatulence. If you experience any of these symptoms, speak to your doctor for medical advice.

7. Tell your doctor about all medications you’re taking

Be sure to tell your doctor about all other medications you’re taking, including over-the-counter drugs, vitamins, and herbal supplements, as they can interact with Amitiza.

8. Get regular medical check ups

It is important to get regular medical check ups and monitor your medical conditions. Your doctor will monitor your side effects and may adjust your dose of Amitiza as needed.

Medically reviewed

A medical professional has reviewed this article.

Jamie Winn, PharmD
Jamie Winn, PharmD

Jamie Winn, PharmD

Medical Writer & Reviewer

Jamie Winn, PharmD

Medical Writer & Reviewer

Dr. Jamie Winn received his Doctor of Pharmacy in 2002 from the University of South Carolina College of Pharmacy, Columbia, SC. Jamie is a medical reviewer for NiceRx.

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Sources (4)

  1. Medical News Today - Amitiza (lubiprostone)

  2. WebMD - lubiprostone (Rx)

  3. National Library of Medicine - Lubiprostone: a novel treatment for chronic constipation

  4. FDA - highlights of prescribing information for Amitiza

The content on this website is intended for information purposes only. It does not constitute medical advice. The information on this website should not be relied upon and is not a substitute for professional medical advice. You should always speak to your doctor regarding the risks and benefits of any treatment.