This medication is used to treat disorders caused by decreased movement of the stomach and upper intestines (such as diabetic gastroparesis, gastritis). It works by increasing stomach emptying and movement of the upper intestines. Treating these disorders can help decrease symptoms such as nausea, vomiting, heartburn, and constant feeling of stomach fullness.

This medication is also used to prevent side effects (such as nausea, vomiting) from certain medications used to treat Parkinson's disease (including levodopa, dopamine agonists such as pergolide).

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.

This drug may also be used for nausea and vomiting from other causes (such as chemotherapy, migraine headaches).

Take this medication by mouth as directed by your doctor, usually 3 times daily (15 to 30 minutes before meals).

The dosage is based on your medical condition and response to treatment.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of serious side effects (such as irregular heartbeat, tardive dyskinesia) will increase. See also Side Effects and Warning section.

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.

Tell your doctor if your condition lasts or gets worse.

See also Warning section.

Headache, dry mouth, diarrhea, or abdominal cramping may occur. If any of these effects last or get 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.

Tell your doctor right away if you have any serious side effects, including:

• swelling of the ankles/feet
• unusual tiredness
• mental/mood changes (such as nervousness, irritability, restlessness)
• hot flashes
• breast swelling/pain
• unusual leakage of milk from the breast
• changes in menstrual periods
• decreased sexual ability
• drooling/trouble swallowing
• shaking (tremor)
• muscle spasm/stiffness
• mask-like expression of the face

Rarely, domperidone may cause face/muscle twitching and uncontrollable movements (tardive dyskinesia). In some cases, this condition may be permanent. Tell your doctor right away if you develop any uncontrollable movements such as lip smacking, mouth puckering, or other unusual movements.

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 domperidone, 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:

• recent stomach/intestinal surgery
• bleeding/blockage/hole in the intestines/stomach
• a certain tumor of the pituitary gland (prolactinoma)
• breast cancer
• liver disease
• kidney disease
• decreased or no stomach acid (achlorhydria)

Domperidone may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using domperidone, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions:

• certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG)
• family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death)

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using domperidone safely.

Older adults may be at greater risk for very serious irregular heartbeats (arrhythmias) and QT prolongation (see above).

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

Domperidone passes into breast milk in small amounts. Consult your doctor before breastfeeding.

See also How to Use section.

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.

A product that may interact with this drug is:

• pramlintide

Many drugs besides domperidone may affect the heart rhythm (QT prolongation), such as amiodarone, bepridil, disopyramide, dofetilide, droperidol, halofantrine, levomethadyl, mesoridazine, pimozide, procainamide, quinidine, ranolazine, sotalol, sparfloxacin, thioridazine, ziprasidone, among others.

Other medications can affect the removal of domperidone from your body, which may affect how domperidone works. Examples include certain azole antifungals (such as ketoconazole, voriconazole), cimetidine, cobicistat, certain macrolide antibiotics (such as clarithromycin, erythromycin), HIV protease inhibitors (such as nelfinavir), nefazodone, rifamycins (such as rifabutin), ritonavir, certain drugs used to treat seizures (such as carbamazepine), telithromycin, among others.

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. Symptoms of overdose may include: fast/slow/irregular heartbeat, severe dizziness, drowsiness, muscle stiffness/spasm/twitching.

Do not share this medication with others.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. 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.