What the label lists and what reports show
Pantoprazole side effects
Pantoprazole's FDA label: “Most common adverse reactions are: • For adult use (>2%): headache, diarrhea, nausea, abdominal pain, vomiting, flatulence, dizziness, and arthralgia.” FAERS holds 330,183 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is chronic kidney disease (29,250 reports).
- Generic listed
Check it at the source: the pantoprazole FDA label on DailyMed (effective May 18, 2026, Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of PROTONIX?PROTONIX can cause serious side effects, including: • See " What is the most important information I should know about PROTONIX? " • Low vitamin B-12 levels in your body can happen in people who have taken PROTONIX for a long time (more than 3 years). Tell your doctor if you have symptoms of low vitamin B-12 levels, including shortness of breath, lightheadedness, irregular heartbeat, muscle weakness, pale skin, feeling tired, mood changes, and tingling or numbness in the arms and legs. • Stomach growths (fundic gland polyps). People who take PPI medicines for a long time have an increased risk of developing a certain type of stomach growths called fundic gland polyps, especially after taking PPI medicines for more than 1 year. • Severe skin reactions. PROTONIX can cause rare but severe skin reactions that may affect any part of your body. […]
Source: FDA drug label, Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., effective May 18, 2026 (SPL set 08098cb2-c048-4640-f387-6beec4a38936), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions are: • For adult use (>2%): headache, diarrhea, nausea, abdominal pain, vomiting, flatulence, dizziness, and arthralgia.
Table 3: Adverse Reactions Reported in Clinical Trials of Adult Patients with GERD at a Frequency of >2%
| Reaction | PROTONIX (n=1473) % | Comparators (n=345) % | Placebo (n=82) % |
|---|---|---|---|
| Headache | 12.2 | 12.8 | 8.5 |
| Diarrhea | 8.8 | 9.6 | 4.9 |
| Nausea | 7.0 | 5.2 | 9.8 |
| Abdominal pain | 6.2 | 4.1 | 6.1 |
| Vomiting | 4.3 | 3.5 | 2.4 |
| Flatulence | 3.9 | 2.9 | 3.7 |
| Dizziness | 3.0 | 2.9 | 1.2 |
| Arthralgia | 2.8 | 1.4 | 1.2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are described below and elsewhere in labeling: • Acute Tubulointerstitial Nephritis [see Warnings and Precautions (5.2) ] • Clostridium difficile- Associated Diarrhea [see Warnings and Precautions (5.3) ] • Bone Fracture [see Warnings and Precautions (5.4) ] • Severe Cutaneous Adverse Reactions [see Warnings and Precautions (5.5) ] • Cutaneous and Systemic Lupus Erythematosus [see Warnings and Precautions (5.6) ] • Cyanocobalamin (Vitamin B-12) Deficiency [see Warnings and Precautions (5.7) ] • Hypomagnesemia and Mineral Metabolism [see Warnings and Precautions (5.8) ] • Fundic Gland Polyps [see Warnings and Precautions (5.10) ] Most common adverse reactions are: • For adult use (>2%): headache, diarrhea, nausea, abdominal pain, vomiting, flatulence, dizziness, and arthralgia. ( 6.1 ) • For pediatric use (>4%): URI, headache, fever, diarrhea, vomiting, rash, and abdominal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience The adverse reaction profiles for PROTONIX (pantoprazole sodium) For Delayed-Release Oral Suspension and PROTONIX (pantoprazole sodium) Delayed-Release Tablets are similar. …
Source: FDA drug label, Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., effective May 18, 2026 (SPL set 08098cb2-c048-4640-f387-6beec4a38936), via openFDA; the full label on DailyMed
What do FAERS reports show?
330,183 reports list pantoprazole among the medicines taken, each a report of something that happened, not proof the medicine caused it; 36,440 are coded as a death and 139,578 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 13 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Pantoprazole: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions