Generic name: lansoprazole [ lan-SOE-pra-zol ]
Brand names: FIRST Lansoprazole, Prevacid
Drug class: Proton pump inhibitors

Medically reviewed by Melisa Puckey, BPharm. Last updated on Feb 29, 2024.

What is lansoprazole?

Lansoprazole is a proton pump inhibitor. Lansoprazole decreases the amount of acid produced in the stomach.

Lansoprazole is used to treat and prevent stomach and intestinal ulcers, erosive esophagitis (damage to the esophagus from stomach acid), and other conditions involving excessive stomach acid such as Zollinger-Ellison syndrome.

Over-the-counter lansoprazole (Prevacid OTC) is used to treat frequent heartburn that happens 2 or more days per week. This medicine is not for the immediate relief of heartburn symptoms.

Warnings

Lansoprazole can cause kidney problems. Tell your doctor if you are urinating less than usual, or if you have blood in your urine.

This medicine can cause diarrhea, which may be a sign of a new infection. Call your doctor if you have diarrhea that is watery or has blood in it.

Lansoprazole may cause new or worsening symptoms of lupus. Tell your doctor if you have joint pain and a skin rash on your cheeks or arms that worsens in sunlight.

You may be more likely to have a broken bone while taking this medicine long term or more than once per day.

If you also take sucralfate (Carafate), avoid taking it at the same time you take this medicine. Sucralfate can make it harder for your body to absorb lansoprazole. Wait at least 30 minutes after taking this medicine before you take sucralfate.

Before taking this medicine

You should not use lansoprazole if you are allergic to it, or if you take any medicine that contains rilpivirine (Edurant, Complera, Odefsey).

Heartburn can mimic early symptoms of a heart attack. Get emergency medical help if you have chest pain that spreads to your jaw or shoulder and you feel anxious or light-headed.

Tell your doctor if you have ever had:

• liver disease;

• lupus;

• low levels of magnesium in your blood; or

• osteoporosis or low bone mineral density (osteopenia).

Do not use over-the-counter lansoprazole (Prevacid OTC) without the advice of a doctor if you have:

• trouble or pain with swallowing;

• bloody or black stools; vomit that looks like blood or coffee grounds;

• heartburn that has lasted for over 3 months;

• frequent chest pain, heartburn with wheezing;

• unexplained weight loss;

• nausea or vomiting, stomach pain; or

• an electrolyte imbalance or metabolic disorder.

Some forms of lansoprazole may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

You may be more likely to have a broken bone in your hip, wrist, or spine while taking a proton pump inhibitor long-term or more than once per day. Talk with your doctor about ways to keep your bones healthy.

Some conditions are treated with a combination of lansoprazole and antibiotics. Use all medications as directed by your doctor

Do not give lansoprazole to a child younger than 1 year old. Prevacid OTC is not approved for use by anyone younger than 18 years old.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

How should I take lansoprazole?

Use lansoprazole exactly as directed on the label, or as prescribed by your doctor and read all medication guides or instruction sheets.

Lansoprazole is usually taken before eating. Prevacid OTC should be taken in the morning before you eat breakfast.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Shake the lansoprazole oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Swallow the lansoprazole capsule whole and do not crush, chew, break, or open it.

Remove an orally disintegrating tablet from the package only when you are ready to take the medicine. Place the tablet in your mouth and allow it to dissolve, without chewing. Swallow several times as the tablet dissolves.

Use lansoprazole for the full prescribed length of time, even if your symptoms quickly improve.

Prevacid OTC should be taken only once daily for 14 days. It may take up to 4 days for full effect. Allow at least 4 months to pass before you start another 14-day treatment with Prevacid OTC.

Call your doctor if your symptoms do not improve or if they get worse while you are taking lansoprazole. If you take Prevacid OTC, call your doctor if your heartburn gets worse over the 14-day treatment, or if you need treatment more than once every 4 months.

Some conditions are treated with a combination of lansoprazole and antibiotics. Use all medications as directed.

If you use lansoprazole for longer than 3 years, you could develop a vitamin B-12 deficiency. Talk to your doctor about how to manage this condition if you develop it.

Store at room temperature away from moisture, heat, and light. Do not freeze the liquid medicine.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

This medicine can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Lansoprazole side effects

Get emergency medical help if you have signs of an allergic reaction ro lansoprazole: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody;

• new or unusual pain in your wrist, back, hip, or thigh;

• a seizure (convulsions);

• kidney problems - fever, nausea, little or no urination, blood in your urine, swelling, rapid weight gain;

• low magnesium - dizziness, fast or irregular heart rate, tremors (shaking) or jerking muscle movements, feeling jittery, muscle cramps, muscle spasms in your hands and feet, cough or choking feeling; or

• new or worsening symptoms of lupus - joint pain, and a skin rash on your cheeks or arms that worsens in sunlight.

Taking lansoprazole long-term may cause you to develop stomach growths called fundic gland polyps. Talk with your doctor about this risk.

If you use lansoprazole for longer than 3 years, you could develop a vitamin B-12 deficiency. Talk to your doctor about how to manage this condition if you develop it.

Common lansoprazole side effects may include:

• nausea, stomach pain;

• diarrhea, constipation; or

• headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

What other drugs will affect lansoprazole?

Sucralfate (Carafate) can make it harder for your body to absorb lansoprazole. Wait at least 30 minutes after taking lansoprazole before you take sucralfate.

Tell your doctor if you use methotrexate.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect lansoprazole, and some drugs should not be used at the same time. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use lansoprazole only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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