← All drugs
Proton pump inhibitorGERD · Ulcers · Acid reflux

Pantoprazole (Protonix)

A proton pump inhibitor (PPI) that powerfully reduces stomach acid production. Very effective for GERD and ulcer healing, but long-term use carries risks that are worth discussing with your doctor.

What it's used for

Gastroesophageal reflux disease (GERD), erosive esophagitis (healing and maintenance), Zollinger-Ellison syndrome, and as part of H. pylori eradication therapy. Often used short-term for stomach protection when taking NSAIDs or corticosteroids.

Typical dosing (adults)

  • GERD / erosive esophagitis: 40 mg once daily for 4–8 weeks.
  • Maintenance: 20–40 mg once daily (reassess periodically).
  • Zollinger-Ellison: 40 mg twice daily (may need higher doses).
  • Take 30–60 minutes before a meal (typically before breakfast). Swallow tablets whole — do not crush or chew.

Key interactions

  • Clopidogrel (Plavix): moderate — pantoprazole has less interaction than omeprazole, but some caution is still advised; discuss with your doctor.
  • Methotrexate: major — PPIs can increase methotrexate blood levels, raising toxicity risk.
  • HIV medications (atazanavir, rilpivirine): major — reduced absorption due to increased stomach pH; avoid combination.
  • Iron, calcium, and magnesium supplements: moderate — reduced absorption with long-term acid suppression.
  • Levothyroxine: moderate — reduced thyroid hormone absorption; may need dose adjustment.

Common side effects

Headache, diarrhea, nausea, abdominal pain, and flatulence. Generally well tolerated short-term. Long-term concerns (months to years): low magnesium, vitamin B12 deficiency, increased risk of C. difficile infection, possible increased fracture risk (hip, wrist, spine), and rebound acid hypersecretion when stopping after prolonged use.

Who should be cautious

  • Long-term users (reassess need regularly; use the lowest effective dose).
  • Osteoporosis risk (long-term PPIs may increase fracture risk).
  • Low magnesium (get levels checked if on PPI for extended periods).
  • Liver disease (dose may need reduction in severe cases).
  • Patients on HIV medications that require stomach acid for absorption.

What to ask your pharmacist

  • Do I still need to be on a PPI, or can I try stepping down?
  • Should I take my iron or calcium supplement at a different time?
  • I've been on pantoprazole for over a year — should I get my B12 and magnesium checked?
  • What's the best way to wean off a PPI to avoid rebound acid?