Omeprazole
Indications for use
- Short-term treatment of reflux symptoms (such as heartburn and acid regurgitation) in adults
Age
- 18 years +
Dose/Directions
- One 20 mg tablet once a day
- Swallow whole with half a glass of water; do not chew or crush. May be taken with food or on an empty stomach
Duration
- It might be necessary to take the tablets for 2–3 consecutive days to achieve improvement of symptoms
- Discontinue once complete relief of symptoms has occurred; treatment should not exceed 2 weeks without consulting a doctor
- If no symptom relief is obtained within 2 weeks of continuous treatment, the patient should seek medical advice
Contra-indications/referral criteria
- Hypersensitivity to omeprazole, substituted benzimidazoles or any of the excipients
- Co-administration with nelfinavir is contra-indicated
- Unintentional weight loss, anaemia, gastrointestinal bleeding, dysphagia, persistent vomiting or vomiting with blood (diagnosis of a serious condition may be delayed or masked)
- Previous gastric ulcer or gastrointestinal surgery
- Jaundice, hepatic impairment or liver disease (or any other serious disease affecting general well-being)
- Aged over 55 years with new or recently changed symptoms
- Already taking a PPI or H2-receptor antagonist prescribed by a doctor
- On continuous NSAID treatment
Examples of drug interactions
- Co-administration with atazanavir or nelfinavir is not recommended (reduced antiretroviral plasma levels)
- Clopidogrel: concomitant use is discouraged; omeprazole may reduce the antiplatelet effect
- Warfarin and other coumarin anticoagulants: monitoring of INR is recommended when initiating or stopping concomitant omeprazole
- Methotrexate: increased levels of methotrexate when co-administered with PPIs have been reported
- Phenytoin: monitor plasma concentrations when treatment with omeprazole is introduced or withdrawn
- Gastric acid suppression may decrease or increase the absorption of medicines with a gastric pH dependent absorption (e.g. ketoconazole, itraconazole, erlotinib)
Side-effects
- Among the most common: headache, abdominal pain, diarrhoea, constipation, nausea, vomiting, flatulence
Other pertinent information
- Not intended to provide immediate symptom relief
- Available OTC as omeprazole 20 mg gastro-resistant tablets in packs of up to 14 tablets (GSL, e.g. Pyrocalm Control)
- OTC omeprazole 10 mg (Zanprol 10 mg, P) has been discontinued; current OTC omeprazole is the 20 mg strength
- Reclassified POM→P: 2004 (10 mg), 2013 (20 mg); P→GSL: 2019 (20 mg)