See also Warning section.

Tenapanor is used to treat a certain bowel problem (irritable bowel syndrome with constipation). It works by increasing fluid in your intestines and helping speed up movement of food through the gut. Tenapanor may improve stool texture and lessen abdominal pain/discomfort.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

Tenapanor is also available in other brands and other strengths to lower high blood phosphate levels in people who are on dialysis due to long-term kidney disease. Do not take this medication with any other product that contains tenapanor.

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking tenapanor and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth as directed by your doctor, usually twice daily: once immediately before your first meal of the day, and once before dinner. Swallow the tablets whole. Do not crush or chew the tablets.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Tell your doctor if your condition does not get better or if it gets worse.

Diarrhea may occur. If this effect lasts or gets worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Stop taking this medication and tell your doctor right away if you have any serious side effects, including:

• severe diarrhea

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking tenapanor, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• stomach/intestinal blockage

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store in the original container at room temperature away from light and moisture. Do not store in the bathroom. Keep the drying agent (desiccant) in the container. Tightly close the container when not in use. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.