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Proton Pump Inhibitor Pregnancy: §4.6, verbatim: 'Pregnancy — Results from three prospective epidemiological studies (more than 1 000 exposed outcomes) indicate no adverse effects of omeprazole on pregnancy or on the health of the foetus/newborn child. Omeprazole can be used during pregnancy. Breast-feeding — Omeprazole is excreted in breast milk but is not likely to influence the child when therapeutic doses are used. Fertility — Animal studies with the racemic mixture omeprazole, given by oral administration do not indicate effects with respect to fertility.'

Omeprazole (Elderly)

Brand names: Losec, Prilosec

Used in: Gastrointestinal Bleeding

Omeprazole (in older people) is a proton pump inhibitor used for acid-related disorders such as reflux, peptic ulcer and gastroprotection; this page focuses on PPI use in the elderly.

Adult dose

Dose: 20 mg once daily by mouth for most indications, with no dose change for age — §4.2 Special populations, 'Elderly': 'Dose adjustment is not needed in the elderly (see section 5.2).' Per-indication, verbatim from §4.2 — Reflux oesophagitis: 'The recommended dose is Losec 20 mg once daily' (severe oesophagitis: 'Losec 40 mg once daily is recommended'). Symptomatic gastro-oesophageal reflux disease: 'The recommended dose is Losec 20 mg daily. Patients may respond adequately to 10 mg daily, and therefore individual dose adjustment should be considered.' Long-term management of healed reflux oesophagitis: 'the recommended dose is Losec 10 mg once daily. If needed, the dose can be increased to Losec 20 mg to 40 mg once daily.' Duodenal ulcer: 'Losec 20 mg once daily' ('In patients with poorly responsive duodenal ulcer Losec 40 mg once daily is recommended'). Gastric ulcer: 'The recommended dose is Losec 20 mg once daily' ('In patients with poorly responsive gastric ulcer Losec 40 mg once daily is recommended'). Prevention of relapse of duodenal ulcer: 'the recommended dose is Losec 20 mg once daily. In some patients a daily dose of 10 mg may be sufficient. In case of therapy failure, the dose can be increased to 40 mg.' Prevention of relapse of gastric ulcer: 'the recommended dose is Losec 20 mg once daily. If needed the dose can be increased to Losec 40 mg once daily.' Treatment of NSAID-associated gastric and duodenal ulcers: 'the recommended dose is Losec 20 mg once daily.' Prevention of NSAID-associated ulcers in patients at risk — the group this page's population usually falls into, verbatim: 'For the prevention of NSAID - associated gastric ulcers or duodenal ulcers in patients at risk (age > 60, previous history of gastric and duodenal ulcers, previous history of upper GI bleeding) the recommended dose is Losec 20 mg once daily.' Zollinger-Ellison syndrome and H. pylori eradication use different regimens — see notes.
Route: Oral — Losec 10 mg enteric-coated capsules. §4.2 Method of administration, verbatim: 'It is recommended to take Losec capsules in the morning, swallowed whole with half a glass of water. The capsules must not be chewed or crushed.' For swallowing difficulties, verbatim: 'Patients can open the capsule and swallow the contents with half a glass of water or after mixing the contents in a slightly acidic fluid e.g. fruit juice or applesauce, or in non-carbonated water. Patients should be advised that the dispersion should be taken immediately (or within 30 minutes) and always be stirred just before drinking and rinsed down with half a glass of water. Alternatively, patients can suck the capsule and swallow the pellets with half a glass of water. The enteric-coated pellets must not be chewed.' SCOPE: no intravenous omeprazole label was fetched in this bundle, so the page's 'or IV' route is not sourced and no IV dose is published.
Frequency: Once daily for every indication listed above. (Exceptions within the same SPC: H. pylori eradication regimens are given twice daily for one week — see notes; and in Zollinger-Ellison syndrome, 'When dose exceed Losec 80 mg daily, the dose should be divided and given twice daily.')
SCOPE: oral capsules only, for the acid-related indications listed in the dose field; the page's 'or IV' route is not sourced in this bundle and no intravenous dose is published. || ELDERLY, §4.2 verbatim: 'Dose adjustment is not needed in the elderly (see section 5.2).' || WHY maxDose IS EMPTY: this SPC states no maximum daily dose for any of the indications published above. The only high figures in §4.2 belong to a DIFFERENT indication — Zollinger-Ellison syndrome, verbatim: 'In patients with Zollinger-Ellison syndrome the dose should be individually adjusted and treatment continued as long as clinically indicated. The recommended initial dose is Losec 60 mg daily. All patients with severe disease and inadequate response to other therapies have been effectively controlled and more than 90% of the patients maintained on doses of Losec 20 mg to 120 mg daily. When dose exceed Losec 80 mg daily, the dose should be divided and given twice daily.' Those figures are deliberately NOT used as this page's ceiling. || A separate interaction-specific cap (an eligibility rule, not this dose's ceiling), §4.4 verbatim: if atazanavir plus a PPI is judged unavoidable, 'omeprazole 20 mg should not be exceeded.' || H. PYLORI ERADICATION, §4.2 verbatim: 'Losec 20 mg + clarithromycin 500 mg + amoxicillin 1 000 mg, each twice daily for one week, or Losec 20 mg + clarithromycin 250 mg (alternatively 500 mg) + metronidazole 400 mg (or 500 mg or tinidazole 500 mg), each twice daily for one week or Losec 40 mg once daily with amoxicillin 500 mg and metronidazole 400 mg (or 500 mg or tinidazole 500 mg), both three times a day for one week.' Antibiotic selection 'should consider the individual patient's drug tolerance, and should be undertaken in accordance with national, regional and local resistance patterns and treatment guidelines.' || HEALING TIMES, §4.2: duodenal ulcer usually 2 weeks (a further 2 weeks if not fully healed; 4 weeks for poorly responsive on 40 mg); gastric ulcer usually 4 weeks (a further 4 weeks; 8 weeks for poorly responsive on 40 mg); reflux oesophagitis usually 4 weeks (a further 4 weeks; 8 weeks for severe on 40 mg). Symptomatic GORD: 'If symptom control has not been achieved after four weeks treatment with Losec 20 mg daily, further investigation is recommended.' || This SPC says only to take the capsules in the morning, swallowed whole.

Dose adjustments

Renal

§4.2 Special populations, under the heading 'Renal impairment', verbatim: 'Dose adjustment is not needed in patients with impaired renal function (see section 5.2).'

Hepatic

§4.2 Special populations, under the heading 'Hepatic impairment', verbatim: 'In patients with impaired hepatic function a daily dose of 10 mg to 20 mg may be sufficient (see section 5.2).' Note the label frames this as a dose that 'may be sufficient', NOT as a stated maximum.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • §4.3, verbatim and complete: 'Hypersensitivity to the active substance, substituted benzimidazoles or to any of the excipients listed in section 6.1.'
  • §4.3, verbatim and complete: 'Omeprazole like other proton pump inhibitors (PPIs) must not be used concomitantly with nelfinavir (see section 4.5).'
  • Not a §4.3 contraindication but a §4.4 'not recommended': 'Co-administration of atazanavir with proton pump inhibitors is not recommended (see section 4.5). If the combination of atazanavir with a proton pump inhibitor is judged unavoidable, close clinical monitoring (e.g. virus load) is recommended in combination with an increase in the dose of atazanavir to 400 mg with 100 mg of ritonavir; omeprazole 20 mg should not be exceeded.'
  • Not a §4.3 contraindication but a §4.4 precaution: 'As a precaution, concomitant use of omeprazole and clopidogrel should be discouraged.'
  • Not a §4.3 contraindication but a §4.4 diagnostic caution: 'In the presence of any alarm symptom (e.g. significant unintentional weight loss, recurrent vomiting, dysphagia, haematemesis or melena) and when gastric ulcer is suspected or present, malignancy should be excluded, as treatment may alleviate symptoms and delay diagnosis.'
  • INCOMPLETE LIST WARNING: §4.4 was truncated at the source-fetch limit, so any further bars or precautions stated after the fracture-risk paragraph were not retrieved.

Side effects

  • §4.8 summary, verbatim: 'The most common side effects (1 to 10% of patients) are headache, abdominal pain, constipation, diarrhoea, flatulence and nausea/vomiting.'
  • Common (≥1/100 to <1/10), §4.8: headache; abdominal pain, constipation, diarrhoea, flatulence, nausea/vomiting, fundic gland polyps (benign)
  • Uncommon (≥1/1,000 to <1/100), §4.8: insomnia; dizziness, paraesthesia, somnolence; vertigo; increased liver enzymes; dermatitis, pruritus, rash, urticaria; fracture of the hip, wrist or spine
  • Rare (≥1/10,000 to <1/1,000), §4.8: leukopenia, thrombocytopenia; hypersensitivity reactions e.g. fever, angioedema and anaphylactic reaction/shock; hyponatraemia; agitation, confusion, depression; taste disturbance; blurred vision; bronchospasm; dry mouth, stomatitis, gastrointestinal candidiasis; hepatitis with or without jaundice; alopecia, photosensitivity, acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS); arthralgia, myalgia; tubulointerstitial nephritis (with possible progression to renal failure)
  • Very rare (<1/10,000), §4.8: agranulocytosis, pancytopenia; aggression, hallucinations; hepatic failure, encephalopathy in patients with pre-existing liver disease; muscular weakness; erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN)
  • Not known, §4.8: 'Hypomagnesaemia; severe hypomagnesaemia may result in hypocalcaemia. Hypomagnesaemia may also be associated with hypokalaemia.'; microscopic colitis; subacute cutaneous lupus erythematosus
  • §4.4/§4.8, verbatim: 'Severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP) have been reported in association with omeprazole treatment.'
  • INCOMPLETE LIST WARNING: §4.8 was truncated at the source-fetch limit part-way through the 'Reproductive system and...' system organ class, so the tail of the adverse-reaction table was not retrieved.

Monitoring

  • Magnesium — §4.4, verbatim: 'Severe hypomagnesaemia has been reported in patients treated with proton pump inhibitors (PPIs) like omeprazole for at least three months, and in most cases for a year... For patients expected to be on prolonged treatment or who take PPIs with digoxin or drugs that may cause hypomagnesaemia (e.g. diuretics), healthcare professionals should consider measuring magnesium levels before starting PPI treatment and periodically during treatment.'
  • Vitamin B12 — §4.4, verbatim: 'Omeprazole, as all acid-blocking medicines, may reduce the absorption of vitamin B 12 (cyanocobalamin) due to hypo- or achlorhydria. This should be considered in patients with reduced body stores or risk factors for reduced vitamin B 12 absorption on long-term therapy.'
  • Fracture risk — §4.4, verbatim: 'Proton pump inhibitors, especially if used in high doses and over long durations (> 1 year), may modestly increase the risk of hip, wrist and spine fracture, predominantly in the elderly or in presence of other recognised risk factors. Observational studies suggest that proton pump inhibitors may increase the overall risk of fracture by 10 to 40%... Patients at risk of osteoporosis should receive care according to current clinical guidelines.'
  • CYP2C19 interactions — §4.4, verbatim: 'Omeprazole is a CYP2C19 inhibitor. When starting or ending treatment with omeprazole, the potential for interactions with drugs metabolised through CYP2C19 should be considered.'
  • Exclude malignancy in the presence of alarm symptoms before attributing them to acid disease (§4.4, quoted in full under contraindications).
  • INCOMPLETE LIST WARNING: §4.4 was truncated at the source-fetch limit; any further monitoring advice beyond the fracture paragraph was not retrieved.

Clinical monograph

How it works

It irreversibly inhibits the gastric H+/K+-ATPase (proton pump) in parietal cells, profoundly reducing gastric acid secretion.

Prescribing in practice

  • In older people review the ongoing need and deprescribe when possible, as long-term PPI use is associated with hypomagnesaemia, increased fracture risk, vitamin B12 deficiency, Clostridioides difficile and other enteric infections, and hyponatraemia.
  • It inhibits CYP enzymes and reduces the antiplatelet effect of clopidogrel; review interacting medicines.
  • PPIs can mask the symptoms of gastric cancer, so investigate alarm features before attributing them to benign reflux.

Monitoring

On prolonged therapy in older patients consider checking magnesium and, where relevant, vitamin B12, and periodically reassess whether continued treatment is needed.

Counselling the patient

  • Take before food, typically before breakfast, for best effect.
  • Tell a clinician about muscle cramps, tingling or persistent diarrhoea on long-term use.

Evidence & guidelines

MHRA advice notes the risk of hypomagnesaemia and fractures with prolonged PPI use, supporting periodic review and deprescribing in older adults.

Reference: NICE NG1; SIGN 142; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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