What to Know About Protonix (Pantoprazole)

Proton-pump inhibitor to treat gastroesophageal reflux disease (GERD)

Table of Contents
View All
Table of Contents

Protonix (generic name pantoprazole) is a type of drug that’s called a proton pump inhibitor. This drug works by lowering the production of acid in the stomach. Protonix is used to treat certain conditions in the stomach and esophagus, such as acid reflux, gastroesophageal reflux disease (GERD), and erosive esophagitis.

Protonix is approved for use in adults and children over the age of 5 years. It is most often given orally as a pill, but there is also an oral liquid suspension form and an intravenous form that is given by infusion into a vein.

A pharmacist gives a recommendation to a customer.
Getty Images / SDI Productions / E+


Protonix is approved by the Food and Drug Administration (FDA) to treat conditions of the stomach and esophagus. It is used for the short-term treatment (usually eight weeks or less) of GERD. It may also be prescribed for a longer period of time as maintenance therapy for erosive esophagitis.

Protonix is also used as a treatment for conditions where the stomach produces too much acid, including Zollinger-Ellison syndrome.

Before Taking

Erosive Esophagitis

Erosive esophagitis is when the lining of the esophagus is inflamed and irritated. This is a problem that may occur as a complication of GERD.

GERD is a condition that may cause signs and symptoms such as heartburn (a burning feeling in the chest), regurgitation, and nausea that may be more severe after a meal and when lying down. Other symptoms can include sore throat, hoarseness, chronic cough, wheezing, bad breath, chest pain, and a feeling like there is something in the throat.

Erosive esophagitis may cause symptoms of burning in the throat, difficulty swallowing, a sour or bitter taste in the mouth, feeling like something is stuck in the throat, and blood either in vomit or in the stool (which may be black and look like tar). Erosive esophagitis may be suspected when some of the symptoms are present.

This condition is usually diagnosed with the use of an endoscopy procedure. During an endoscopy, an instrument is passed into the mouth and down through the esophagus. A healthcare provider can see the inside of the esophagus and if there is any inflammation as well as take biopsies (small pieces of tissue) for analysis.

Erosive esophagitis can be a serious condition which, in rare cases, may lead to the development of cancer. Treatment for erosive esophagitis may include a proton pump inhibitor, such as Protonix, either for a short course (eight weeks) or longer if needed.

Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome is a rare condition that causes the growth of tumors in the pancreas or the duodenum (the first part of the small intestine). These tumors produce a hormone, which, in turn, causes the stomach to overproduce acid. The excess stomach acid can lead to the development of ulcers.

A diagnosis may be made with endoscopy and ultrasound or other imaging tests. Surgery will be needed to remove the tumors. A proton pump inhibitor is also used to decrease the amount of acid being produced.

Precautions and Contraindications

It’s not recommended that Protonix be taken with certain HIV medications. Protonix may lower the amount of antiretroviral medications, such as atazanavir and nelfinavir, in the body. This might result in HIV being less well controlled and it’s recommended that Protonix be avoided if these drugs are being taken.

Use with rilpivirine is contraindicated. For other retroviral medications, check the prescribing information and consult a healthcare provider.

Proton pump inhibitors such as Protonix may cause a serum increase of methotrexate. That means that for those who are taking higher doses of methotrexate, a proton pump inhibitor may increase the risk of methotrexate toxicity.

Studies have shown that proton pump inhibitors may cause an increased international normalised ratio (INR) and prothrombin time in people who are also receiving the anticoagulant warfarin. This means that it may take longer for blood to clot, which increases the risk of severe bleeding.

It may be necessary to change the dosage of warfarin and/or for a healthcare provider to monitor INR and prothrombin time if Protonix is prescribed.

Talk to your healthcare provider about all medications, supplements, and vitamins that you currently take. While some drugs pose minor interaction risks, others may outright contraindicate use or prompt careful consideration as to whether the pros of treatment outweigh the cons in your case.

Other Proton Pump Inhibitors

Other brands of proton pump inhibitors include:


The manufacturer has a recommended dosage for adults and children. However, the healthcare provider that prescribes the drug will specify the dosage, while taking into account age, general health, and the condition for which Protonix is being prescribed. 

Protonix is a tablet that’s taken orally. It comes in dosages of 20 milligrams (mg) and 40 mg. Dosages are defined for the treatment of GERD and overactive acid production in adults. However, for children, a safe dosage is only outlined for treating GERD, because a safe dosage for overactive acid production is not established.

The usual dosage in adults aged 18 and older:

  • For GERD is 40 mg once a day
  • For overactive acid production (including Zollinger-Ellison syndrome) is 40 mg twice a day

The usual dosage in children between the ages of 5 and 17 years:

  • For GERD, in children weighing between 15 and 40 kg, is 20 mg once a day
  • For GERD, in children weighing 40 kg and over, is 40 mg once a day

All listed dosages are according to the drug manufacturer. Check your prescription and talk to your healthcare provider to make sure you are taking the right dose for you.

How to Take and Store

Protonix can be taken with or without food. It’s recommended that it be taken at approximately the same time every day. It shouldn’t be crushed, cut, or chewed. People who are taking Protonix may also take over the counter antacids.

If you miss a dose, take it as soon as you remember. However, if it’s almost time for the next dose, take the next dose at the usual time. Don’t double up doses or take more than one dose at a time. 

Protonix should be stored at 20 to 25 C (68 to 77 F). It may be stored for a brief period to a lower temperature of 15 C (59 F) or a high of 30 C (86 F).

In the case of GERD, Protonix is only prescribed for eight weeks or less to start, so refills, for this reason, are not common. If this medication is needed for a longer time in order to treat GERD or erosive esophagitis, check with a healthcare provider for refills.


The use of Protonix in pregnant people has not been extensively studied. The FDA has not assigned a pregnancy category to Protonix. Studies on pregnant rats receiving Protonix haven’t shown any increase in the risk of birth defects.

In humans, there is some data from one observational study done on 53 pregnant people in Europe, which didn’t show any increase in the rate of major birth defects. The manufacturer does indicate the Protonix may “harm” the fetus and therefore, people who are pregnant or plan to become pregnant should talk to a healthcare provider about the potential risks.

Protonix does pass into breast milk, and a small amount has been found in the breast milk of a nursing person after taking one 40 mg dose. There weren't any reports of adverse effects on the baby, but there are no studies on the long-term effects of Protonix on nursing parents and babies.

The benefits of Protonix should be weighed against the risks in the case of people who are nursing a baby.

In children under the age of 18 years, there is no safety data on the use of Protonix for more than eight weeks. Erosive esophagitis is uncommon in children, so studying the safety of a proton pump inhibitor for longer periods of time in this age group is challenging.

There is no dosage form of Protonix in tablet form that is appropriate for children under the age of 5 years. Protonix was not found to be effective to treat GERD in infants, and therefore is not recommended for children under the age of 1 year.

Side Effects


Some of the common side effects of Protonix in adults include:

  • Diarrhea
  • Dizziness
  • Gas
  • Headache
  • Joint pain
  • Nausea
  • Stomach-area (abdominal) pain
  • Vomiting

The common side effects of Protonix in children include:

  • Diarrhea
  • Fever
  • Headache
  • Rash
  • Stomach-area (abdominal) pain
  • Vomiting
  • Upper respiratory infection 

Warnings and Interactions

Protonix is associated with certain types of severe adverse effects and events. People who are taking Protonix should let their healthcare provider know if they’ve experienced any of the signs and symptoms associated with these serious side effects.

Acute Interstitial Nephritis

Proton pump inhibitors are associated with the risk of developing chronic kidney disease. Acute interstitial nephritis can occur at any point after starting Protonix. Signs and symptoms of kidney disease include urinating (peeing) less and blood in the urine. If these symptoms start, they should be reported to a healthcare provider right away.

Clostridioides difficile (C. diff) Infection

Taking proton pump inhibitors has been shown to be a risk factor of developing an infection with a type of bacteria called C. difficile.

This bacteria is normally found in the human intestines but when it overgrows it can cause symptoms of diarrhea, fever, nausea, loss of appetite and abdominal pain. If these symptoms occur they should be reported to a healthcare provider right away.


A risk of bone fractures in the hip, wrist, or spine has been shown to be increased in people who take proton pump inhibitors for a year or more. The risk is multi-factorial and may be related to the lowered absorption of certain vitamins and minerals in the setting of a proton pump inhibitor.

It’s important that the use of Protonix be discussed with a healthcare provider if a fracture occurs.

Lupus Erythematosus

Lupus is an autoimmune condition that causes a person’s own immune cells to attack the body. Certain types of lupus have been associated with the use of a proton pump inhibitor. People who have lupus have also reported a worsening of their condition after receiving a proton pump inhibitor.

Symptoms of joint pain or a rash that worsens in the sun that is new (or in the case of lupus that’s already established getting worse) should be discussed with a healthcare provider right away.

Vitamin B12 Levels

Taking Protonix for more than three years has resulted in low levels of vitamin B-12. This is because proton pump inhibitors may prevent vitamin B12 from being absorbed.

Complications of low levels of vitamin B12 can include anemia (which causes shortness of breath, lightheadedness, irregular heartbeat, muscle weakness, pale skin, feeling tired), nerve problems (which causes tingling or numbness in the arms and legs), myelopathy (a spinal cord condition that causes numbness and tingling) and dementia (which causes mood changes and cognitive problems).

Magnesium Levels

Proton pump inhibitors have been shown to cause low magnesium levels, though the reason for this is not completely understood. Taking Protonix for three months has resulted in lowered levels of magnesium in the body.

Low magnesium can cause signs and symptoms including seizures, dizziness, irregular heartbeat, jitteriness, muscle aches or weakness, and spasms of the hands, feet, or voice.

Fundic Gland Polyps

The upper portion of the stomach is called the fundus. A polyp is a type of abnormal growth. The use of proton pump inhibitors for more than one year is associated with the growth of these polyps, which look like flat bumps.

Fundic polyps are rarely associated with the risk of cancer. However, if they do develop, it may be recommended that the proton pump inhibitor be stopped. 

Drug Interactions

In addition to the precautions about HIV medications, warfarin, and methotrexate listed above, Protonix may also interact with Cellcept (mycophenolate mofetil). Cellcept is an immunosuppressant drug that is used to help prevent rejection after an organ transplant, or to treat certain immune-mediated conditions, such as Crohn’s disease.

Protonix may decrease the effectiveness of this Cellcept, but the level of this effect has not been established. The recommendation from the manufacturer of Protonix is that it be used in caution in those also receiving Cellcept.

Diagnostic Testing

There are two potential effects of proton pump inhibitors on a blood test and a urine test. 

The first is that proton pump inhibitors may lead to a false-positive in tests for chromogranin A (CgA) levels which are used to look for neuroendocrine tumors (which are a rare type of tumor). It’s recommended that a proton pump inhibitor be stopped for two weeks before a CgA level test.

The second is in urine screening for tetrahydrocannabinol (THC), which is the substance in marijuana that gives the “high.” The use of proton pump inhibitors may cause a false positive in a test for THC. Another type of test might be needed to verify a positive result for THC. 

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wyeth Pharmaceuticals, LLC. PROTONIX (pantoprazole sodium). Prescribing information.

  2. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of GER & GERD.

  3. DeVault KR, Castell DO; American College of Gastroenterology. Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease. Am J Gastroenterol. 2005;100:190-200. doi:10.1111/j.1572-0241.2005.41217.x

  4. Lazarus B, Chen Y, Wilson FP, Sang Y, Chang AR, Coresh J, Grams ME. Proton pump inhibitor use and the risk of chronic kidney disease. JAMA Intern Med. 2016;176:238-46. doi:10.1001/jamainternmed.2015.7193 

  5. Thong BKS, Ima-Nirwana S, Chin KY. Proton pump inhibitors and fracture risk: A review of current evidence and mechanisms involved. Int J Environ Res Public Health. 2019;16:1571. doi:10.3390/ijerph16091571 

  6. Aggarwal N. Drug-induced subacute cutaneous lupus erythematosus associated with proton pump inhibitors. Drugs Real World Outcomes. 2016;3:145-154. doi:10.1007/s40801-016-0067-4 

  7. Miller JW. Proton pump inhibitors, H2-receptor antagonists, metformin, and vitamin B-12 deficiency: clinical implications. Adv Nutr. 2018;9:511S-518S. doi:10.1093/advances/nmy023 

  8. Danziger J, William JH, Scott DJ, et al. Proton-pump inhibitor use is associated with low serum magnesium concentrations. Kidney Int. 2013;83:692-699. doi:10.1038/ki.2012.452 

  9. Martin FC, Chenevix-Trench G, Yeomans ND. Systematic review with meta-analysis: fundic gland polyps and proton pump inhibitors. Aliment Pharmacol Ther. 2016;44:915-925. doi:10.1111/apt.13800 

  10. Mosli HH, Dennis A, Kocha W, Asher LJ, Van Uum SH. Effect of short-term proton pump inhibitor treatment and its discontinuation on chromogranin A in healthy subjects. J Clin Endocrinol Metab. 2012;97:E1731-5. doi:10.1210/jc.2012-1548 

Additional Reading

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.