Read the Medication Guide provided by your pharmacist before you start taking naldemedine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once daily.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Ask your doctor if you should keep using your usual medications for constipation. This medication is used only for constipation caused by opioids. Stop taking naldemedine when you stop using opioid pain medication unless otherwise directed by your doctor.

Tell your doctor if your condition lasts or gets worse.