Lansoprazole is used to treat certain stomach and esophagus problems (such as acid reflux, ulcers). It works by decreasing the amount of acid your stomach makes. It relieves symptoms such as heartburn, difficulty swallowing, and cough. This medication helps heal acid damage to the stomach and esophagus, helps prevent ulcers, and may help prevent cancer of the esophagus. Lansoprazole belongs to a class of drugs known as proton pump inhibitors (PPIs).

Lansoprazole is not recommended for use in children younger than 1 year due to an increased risk of serious side effects. Ask the doctor or pharmacist for details.

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

Take this medication by mouth before a meal as directed by your doctor, usually once daily. The dosage and length of treatment are based on your medical condition and response to treatment. Children's dosage is also based on age and weight.

Handle the tablet with dry hands. Place the tablet on your tongue and let it disintegrate. This takes less than 1 minute. Swallow the remaining particles with or without water. Do not crush, chew, or break the tablet or particles.

If you have trouble swallowing the tablet, you may dissolve it in water and take the mixture by mouth through an oral syringe. Place a tablet in an oral syringe and draw up the correct amount of water for your dose (4 milliliters for a 15-milligram tablet, or 10 milliliters for a 30-milligram tablet) into the syringe. Shake the syringe gently to break apart the tablet, then swallow the liquid within 15 minutes. To make sure that you have taken the entire dose, refill the syringe with water (2 milliliters for the 15-milligram tablet, or 5 milliliters for the 30-milligram tablet), shake again, and swallow all of the liquid. Do not prepare the liquid mixture ahead of time for later use. Doing so may destroy the drug.

If you are giving this medication through a tube into the stomach (nasogastric tube), ask your health care professional for detailed instructions on how to properly mix and give it.

If needed, antacids may be taken along with this medication. If you are also taking sucralfate, take lansoprazole at least 30 minutes before sucralfate.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. Continue to take this medication for the prescribed length of treatment even if you are feeling better.

Tell your doctor if your condition lasts or gets worse. The risk of side effects goes up over time. Ask your doctor how long you should take this medication.

Diarrhea, abdominal pain, or headache 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:

• symptoms of a low magnesium blood level (such as muscle spasms, irregular heartbeat, seizures)
• signs of lupus (such as rash on nose and cheeks, new or worsening joint pain)
• signs of kidney problems (such as change in the amount of urine, pink/bloody urine)

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:

• diarrhea that doesn't stop
• abdominal or stomach pain/cramping
• blood/mucus in your stool

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

Rarely, proton pump inhibitors (such as lansoprazole) have caused vitamin B-12 deficiency. The risk is increased if they are taken every day for a long time (3 years or longer). Tell your doctor right away if you develop symptoms of vitamin B-12 deficiency (such as unusual weakness, sore tongue, or numbness/tingling of the hands/feet).

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:

• fever
• swollen lymph nodes
• 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 lansoprazole, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as dexlansoprazole, omeprazole, pantoprazole); 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:

• liver disease
• lupus

Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have:

• heartburn with lightheadedness/sweating/dizziness
• chest/jaw/arm/shoulder pain (especially with shortness of breath, unusual sweating)
• unexplained weight loss

This medicine may contain aspartame. If you have phenylketonuria (PKU) or any other condition that requires you to restrict your intake of aspartame (or phenylalanine), ask your doctor or pharmacist about using this drug safely.

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

Proton pump inhibitors (such as lansoprazole) may increase your risk for bone fractures, especially with longer use, higher doses, and in older adults. Talk with your doctor or pharmacist about ways to prevent bone loss/fracture, such as by taking calcium (such as calcium citrate) and vitamin D supplements.

Older adults may be more sensitive to the side effects of this drug, especially bone loss and fractures (see above), and C. difficile infection (see Side Effects section).

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. However, similar drugs pass into breast milk. The effects on a nursing infant are unknown. 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:

• methotrexate (especially high-dose treatment)

Some products need stomach acid so that the body can absorb them properly. Lansoprazole decreases stomach acid, so it may change how well these products work. Some affected products include ampicillin, atazanavir, erlotinib, levoketoconazole, nelfinavir, pazopanib, rilpivirine, sparsentan, certain azole antifungals (itraconazole, ketoconazole, posaconazole), among others.

Lansoprazole is very similar to dexlansoprazole. Do not use medications containing dexlansoprazole while using lansoprazole.

This medication may interfere with certain lab tests, possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

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 your doctor instructs you to use this medication regularly for a long time, lab and/or medical tests (such as a magnesium blood test, vitamin B-12 levels) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

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.