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Generic Name

lansoprazole (lan SOAP ra zol)


Trade Name

Prevacid(15 mg, 30 mg)
This drug is not available in a generic form.


What is lansoprazole?

This medicine belongs to a group of drugs called proton pump inhibitors (PPI). The proton pump is the site within the stomach cell where hydrochloric acid is actually made and pumped out into the stomach. The PPIs, therefore, block the formation of acid in the stomach from 80% to almost 90% if enough of the drug is taken.


What is it used for?

The drug is used for almost any condition where stomach acid is causing a problem or tissue injury. These include peptic ulcers in the stomach and duodenum and gastroesophageal reflux disease where acid splashes back into the food pipe and causes injury. An uncommon disease called Zollinger-Ellison Syndrome is where huge amounts of stomach acid and injury occur because of uncontrolled stimulation of the stomach by a hormone called gastrin. It is also used along with antibiotics to cure or eradicate a stomach bacteria infection called Helicobacter pylori which has been shown to cause peptic ulcers. Finally, some physicians will use the drug for simple hyperacidity although the FDA has not approved it for this purpose.


How do I take it?

Follow your physician’s instructions carefully. Lansoprazole is usually taken once or twice a day before a meal. The capsule can be opened and the pellets sprinkled on a tablespoon of applesauce or similar food. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

If you miss a dose in the morning but remember in the afternoon, take it for that day. Otherwise, continue the next day as before and don’t double up.


Are there interactions with food or beverages?

There are no known interactions. However, nicotine, caffeine and alcohol can stimulate stomach acid production or delay ulcer healing. In all honesty, this drug is so potent that many of the previous recommendations about dietary precautions with ulcers are no longer as important.


Are there interactions with other drugs?

An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.

Interactions with this drug may occur with the following:

  • theophylline (Theo-Dur)
  • sucralfate (Carafate)

Certain other drugs require stomach acid to be changed into their active form or to be absorbed. Since lansoprazole eliminates stomach acid so effectively, the absorption of the following drugs may be affected:

  • certain iron pills
  • ketoconazole (Nizoral)
  • ampicillin (Polycillin, Omnipen)
  • digoxin (Lanoxin)
  • If you take any of the above medications, ask your physician. It is okay to take antacids at the same time as lansoprazole.


Is there a problem if I have another disorder or disease?

At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease. Severe advanced liver disease may result in higher blood levels of the drug since the liver helps to metabolize it. Again, discuss with your physician. A disease to be concerned about is H. pylori bacteria infection of the stomach. By itself, the drug reduces the number of bacteria in the stomach but does not cure it. It is possible that the use of the drug long-term, while this infection is present, could seriously damage the stomach. There is a simple blood test available to see if you have ever been infected with this bacteria. Ask your physician.


What about allergies?

People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives and itching. Of course, a person should not take lansoprazole if there has been a previous reaction to this or a similar drug.


What if I’m pregnant, considering pregnancy or breast-feeding?

Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Lansoprazole is ranked B. Always consult the physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

There are no known adverse effects of lansoprazole on sexual function.


Are there other precautions?

There are only a few precautions. The safety in children has not been established. Persons of Asian descent may need a lower dose. And, of course, this and all medicines should be stored in a tight container and away from children.


How long is it safe to take lansoprazole?

The FDA has now approved it for a year. However, physicians from around the world have been prescribing it for much longer and no serious side effects have been noted. It looks like it is a very safe drug even though some minor changes in the stomach cells can be seen when biopsies are reviewed under the microscope.


How about side effects?

Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild, such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately.

For lansoprazole, the following are the observed side effects:


  • diarrhea
  • headache
  • change in taste
  • abdominal pain
  • dizziness
  • nausea
  • rash


A physician’s comment…

Lansoprazole and similar drugs have revolutionized the treatment of acid disorders. Patients often say “it’s like a miracle” and “I can eat anything now”. Not only can ulcer and acid pain be quickly controlled, but the ulcer heals quickly, especially if aspirin and arthritis medications are not taken. A major and certainly welcomed finding is that the drug appears to be safe long-term. However, we still do not have complete long-term data on its safety. So patients should stay in touch with their physician.