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Protonix Side Effects

Generic name: pantoprazole

Medically reviewed by Last updated on Mar 18, 2023.

Note: This document contains side effect information about pantoprazole. Some dosage forms listed on this page may not apply to the brand name Protonix.


More frequent side effects include: diarrhea and nausea. Continue reading for a comprehensive list of adverse effects.

Applies to pantoprazole: oral packet, oral tablet delayed release, oral tablet enteric coated. Other dosage forms:

Serious side effects of Protonix

Along with its needed effects, pantoprazole (the active ingredient contained in Protonix) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking pantoprazole:

Less common

Incidence not known

  • Absence of or decrease in body movements
  • black, tarry stools
  • blindness
  • blistering, peeling, or loosening of the skin
  • bloating
  • bloody or cloudy urine
  • bloody, black, or tarry stools
  • blurred vision
  • chest pain or tightness
  • chills
  • clay-colored stools
  • confusion
  • constipation
  • continuous ringing or buzzing or other unexplained noise in the ears
  • cough
  • dark urine
  • decreased vision
  • diarrhea
  • difficulty with speaking
  • difficulty with swallowing
  • dizziness or lightheadedness
  • drowsiness
  • fast heartbeat
  • feeling of constant movement of self or surroundings
  • fever
  • greatly decreased frequency of urination or amount of urine
  • headache
  • hearing loss
  • high fever
  • hives, itching, or skin rash
  • indigestion
  • joint pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
  • light-colored stools
  • loss of appetite
  • mood or mental changes
  • muscle cramp, pain, stiffness, spasms, or twitching
  • muscle cramps in the hands, arms, feet, legs, or face
  • numbness and tingling around the mouth, fingertips, or feet
  • painful or difficult urination
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pale skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • seizures
  • sensation of spinning
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stomach pain, continuing
  • swelling of the feet or lower legs
  • swollen glands
  • trembling
  • unexplained bleeding or bruising
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin

Other side effects of Protonix

Some side effects of pantoprazole may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Belching
  • bloated or full feeling
  • excess air or gas in the stomach or bowels
  • passing gas
  • trouble sleeping

Incidence not known

  • Increased watering of the mouth

For Healthcare Professionals

Applies to pantoprazole: intravenous powder for injection, oral delayed release tablet, oral granule enteric coated.


The most commonly reported side effects were headache, diarrhea, and injection site thrombophlebitis (in IV formulations).[Ref]

Nervous system

Very common (10% or more): Headache (Up to 26.4%), taste pervasion (Up to 18.2%)

Common (1% to 10%): Dizziness, metallic/bitter taste, somnolence

Rare (0.01% to 0.1%): Taste disorders

Very rare (less than 0.01%): Change to the sense of taste, reduced movement, speech disorder

Frequency not reported: Paresthesia, vertigo

Postmarketing reports: Ageusia, dysgeusia[Ref]

Headache was a very commonly reported side effect in pediatric patients 2 to 16 years of age. In adults, headache occurred most frequently in patients given quadruple therapy (pantoprazole, bismuth, metronidazole, tetracycline) for H pylori infections, but was also very common in triple therapy (pantoprazole, amoxicillin, clarithromycin).

Taste pervasion most frequently occurred in patients given triple therapy, but it was also very common in patients given quadruple therapy.[Ref]


Nasopharyngitis and pharyngolaryngeal pain occurred in pediatric patients between the ages of 2 to 16 years.[Ref]

Very common (10% or more): Nasopharyngitis (up to 13.6%), pharyngolaryngeal pain (up to 13.2%)

Common (1% to 10%): Cough, nasal congestion, pharyngitis

Very rare (less than 0.01%): Change to the sense of smell, dyspnea

Frequency not reported: Upper respiratory tract infection[Ref]


Diarrhea occurred most frequently in patients given quadruple therapy (pantoprazole (the active ingredient contained in Protonix) bismuth, metronidazole, tetracycline) for Helicobacter pylori infections, but was also very common in triple therapy (pantoprazole, amoxicillin, clarithromycin).

Nausea, vomiting, abdominal pain, dry mouth, and constipation were more commonly reported in patients given triple therapy, compared to patients given quadruple therapy.

Fecal and/or tongue discoloration occurred more commonly in patients given quadruple therapy versus patients given triple therapy.[Ref]

Very common (10% or more): Diarrhea (Up to 11.6%)

Common (1% to 10%): Abdominal pain, benign fundic gland polyps/fundic gland polyps, buccal inflammation, constipation, dry mouth, dyspepsia, fecal discoloration, flatulence, heartburn, nausea, oral moniliasis, pruritus ani, tongue discoloration, tongue pain, upper abdominal pain, vomiting

Uncommon (0.1% to 1%): Abdominal discomfort/distention, bloating, loose stools

Rare (0.01% to 0.1%): Colon polyp, rectal disorder

Very rare (less than 0.01%): Increased saliva

Frequency not reported: Clostridium difficile-associated diarrhea, severe eructation[Ref]


Common (1% to 10%): Tiredness

Uncommon (0.1% to 1%): Asthenia, fatigue, malaise

Rare (0.01% to 0.1%): Body temperature increased, fever

Very rare (less than 0.01%): Pain, tinnitus

Frequency not reported: Facial edema[Ref]


Confusion, depression, hallucinations, and disorientation, especially in predisposed patients, occurred with use, and was aggravated in patients with preexisting conditions.[Ref]

Common (1% to 10%): Depression (and all aggravations)

Uncommon (0.1% to 1%): Sleep disorders

Rare (0.01% to 0.1%): Confusion (and all aggravations), disorientation (and all aggravations), hallucination (and all aggravations)

Very rare (less than 0.01%): Anxiety

Postmarketing reports: Insomnia[Ref]


Common (1% to 10%): Increased liver enzymes (transaminases, GGT)

Rare (0.01% to 0.1%): Increased bilirubin

Very rare (less than 0.01%): Cholestatic hepatitis, hepatitis, hepatocellular failure, jaundice

Frequency not reported: Hepatic effects, hepatocellular injury, liver function tests abnormal

Postmarketing reports: Hepatocellular damage[Ref]

Severe hepatocellular damage leading to jaundice/hepatic failure is predicted to have a frequency of 1 in 1,000,000 patients.[Ref]


Common (1% to 10%): Exanthema/exanthemata, rash

Uncommon (0.1% to 1%): Eruption, increased sweating, pruritus

Rare (0.01% to 0.1%): Urticaria

Very rare (less than 0.01%): Erythema multiforme, flushing, Lyell syndrome, photosensitivity/photosensitivity reaction, severe skin reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN)

Frequency not reported: Cutaneous lupus erythematosus, facial edema, fatal skin reactions, fatal TEN, subacute cutaneous lupus erythematosus[Ref]


Common (1% to 10%): Chest pain

Rare (0.01% to 0.1%): Hypertension, peripheral edema, thrombophlebitis

Very rare (less than 0.01%): Circulatory collapse, flushing, hot flushes, substernal chest pain

Frequency not reported: Generalized edema[Ref]


Muscle spasm occurred as a consequence of electrolyte disturbances.[Ref]

Common (1% to 10%): Arthralgia

Uncommon (0.1% to 1%): Fracture of the hip/wrist/spine

Rare (0.01% to 0.1%): Myalgia

Very rare (less than 0.01%): Skeletal pain

Frequency not reported: Bone fracture, elevated creatine phosphokinase (CPK)/elevated creatine kinase (CK), muscle spasm, systemic lupus erythematosus

Postmarketing reports: Rhabdomyolysis[Ref]


Common (1% to 10%): Anorexia

Rare (0.01% to 0.1%): Hyperlipidemia, increased cholesterol, increased triglycerides, lipid increases, weight changes

Frequency not reported: Cyanocobalamin (vitamin B12) deficiency), electrolyte disturbances, hypocalcemia, hypokalemia, hypomagnesemia, hyponatremia, potential for exacerbation of zinc deficiency[Ref]

Hypocalcemia occurred in association with hypomagnesemia.

Anorexia commonly occurred in patients with H pylori.[Ref]


Common (1% to 10%): Injection site thrombophlebitis

Frequency not reported: Injection site reactions[Ref]


Common (1% to 10%): Influenza-like symptoms, moniliasis

Rare (0.01% to 0.1%): Sepsis[Ref]


Rare (0.01% to 0.1%): Anaphylactic reactions, anaphylactic shock, angioedema/Quincke's edema, hypersensitivity, hypersensitivity reactions

Frequency not reported: Allergic reactions

Postmarketing reports: Anaphylaxis[Ref]


Rare (0.01% to 0.1%): Agranulocytosis, anemia

Very rare (less than 0.01%): Increased coagulation time, leukopenia, pancytopenia, thrombocytopenia[Ref]


Uncommon (0.1% to 1%): Blurred vision, visual disturbances

Very rare (less than 0.01%): Conjunctivitis[Ref]


Rare (0.01% to 0.1%): Gynecomastia[Ref]


Very rare (less than 0.01%): Interstitial nephritis (with possible progression to renal failure)

Frequency not reported: Acute interstitial nephritis[Ref]

Frequently asked questions


1. "Product Information. Protonix (pantoprazole)." Wyeth-Ayerst Laboratories (2001):

2. "Product Information. Protonix IV (pantoprazole)." Wyeth-Ayerst Laboratories

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

4. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

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

Some side effects may not be reported. You may report them to the FDA.