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Proton pump inhibitors · Gastrointestinal

Pantoprazole

Pantoloc® · Protonix®(brand names vary by market)

The proton pump inhibitor that stays out of other drugs' way.

Illustration of Pantoprazole as a tabletPAN

Also: modified release, injection, infusion

Mechanism

Irreversibly inhibits the gastric H+/K+ ATPase. Acid secretion resumes only as new pumps are made, which is why the effect outlasts the drug by days.

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Indications

  • Gastro-oesophageal reflux disease
  • Peptic ulcer disease
  • Upper gastrointestinal bleeding
  • Gastroprotection alongside NSAIDs or dual antiplatelet therapy
  • H. pylori eradication regimens

Formulations

TabletModified releaseInjectionInfusion

Dosing concepts

Timing

Taken 30 to 60 minutes before a meal, because it only inhibits pumps that are actively secreting. A dose taken with no meal to follow does much less.

Duration

Most indications are time-limited. An open-ended prescription with no review date is the commonest problem with this class.

Concepts, not prescribing instructions. Practice numbers live in current references and local protocols.

Pharmacokinetics

Bioavailability
~77%
Half-life
~1 h, with acid suppression lasting far longer
Elimination
hepatic: CYP2C19 and CYP3A4, but a much weaker CYP2C19 inhibitor than omeprazole
Protein binding
~98%
Play with these concepts in the PK Lab

Adverse effects

  • Headache and diarrhoeacommon
  • HypomagnesemiaseriousWith prolonged use; can cause tetany, arrhythmia and refractory hypokalemia.
  • C. difficile and enteric infectionserious
  • Vitamin B12 and iron malabsorption with long-term useserious
  • Fracture risk with prolonged high-dose useserious
  • Acute interstitial nephritisseriousIdiosyncratic and easily missed as a cause of unexplained AKI.

Contraindications & precautions

Contraindications

  • Known hypersensitivity

Precautions

  • Long-term use without review
  • Concurrent methotrexate at high dose
  • Masking of gastric malignancy in an undiagnosed patient

Interactions

Monitoring

Whether the indication still applies

The main harm of this class is duration, not dose · At every medication review

Magnesium on prolonged therapy

Under-recognised and occasionally dramatic

B12 and iron in long-term users

Absorption of both depends on acid

Counselling points

  • Take it 30 to 60 minutes before your first meal of the day.
  • Swallow the tablet whole.
  • This is not usually a lifelong medicine; we will review whether you still need it.
  • Tell us about persistent diarrhoea, muscle cramps or palpitations.

Clinical pearls

  • It is the proton pump inhibitor of choice alongside clopidogrel, because its CYP2C19 inhibition is minimal where omeprazole's is not.
  • A patient on long-term therapy with refractory hypokalemia often has hypomagnesemia driving it, and the magnesium has to be replaced before the potassium will hold.

References & review

  • Pantoprazole product monograph (consult the current version for your market) (monograph)
  • Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed. (reference-work)

Last reviewed 2026-08-16 · jurisdiction: global · drug information changes; verify against current references before practice use.