Omeprazole 20 Mg Capsules
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Omeprazole 20 mg Capsules
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each capsule contains omeprazole 20 mg.
Excipient with known effect:
Sucrose
For full list of excipients see section 6.1.
3 PHARMACEUTICAL FORM
Capsule, hard containing gastro-resistant granules
Each capsule consists of an orange body and blue cap and contains white to beige granules marked with O20.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
1. Treatment of reflux oesophagitis disease. In reflux oesophagitis the majority of patients are healed after 4 weeks. Symptom relief is rapid.
2. Treatment of duodenal and benign gastric ulcers including complicating NSAID therapy.
3. Relief of reflux-like symptoms (e.g. heartburn) and/or ulcer-like symptoms (e.g. epigastric pain) associated with acid-related dyspepsia.
4. Treatment and prophylaxis of NSAID-associated benign gastric ulcers, duodenal ulcers and gastroduodenal erosions in patients with a previous history of gastroduodenal lesions who require continued NSAID treatment.
5. Relief of associated dyspeptic symptoms.
6. Helicobacter pylori eradication: When used with in combination with antibiotics, Omeprazole proves effective in the eradication of Helicobacter pylori (Hp) in peptic ulcer disease.
7. Prophylaxis of acid aspiration.
8. Zollinger-Ellison syndrome.
4.2 Posology and method of administration
Oesophageal reflux disease including reflux oesophagitis:
The usual starting dose is 20 mg omeprazole taken once a day for 4 weeks. For those patients not fully healed after the initial 4 week course, healing usually occurs during a further 4-8 weeks treatment.
Omeprazole has also been used in a dose of 40mg once a day in patients with reflux oesophagitis refractory to other therapy. Healing usually occurred within 8 weeks. Continuation of therapy can be considered at a dosage of 20 mg once daily.
Acid reflux disease:
For long-term management, a dose of 10 mg once daily is recommended, increasing to 20 mg if symptoms return.
Duodenal and benign gastric ulcers:
The usual dose is 20 mg omeprazole once daily. With duodenal ulcers, the majority of patients usually are healed after 4 weeks of treatment. The majority of patients with benign gastric ulcer are healed after 8 weeks. In severe or recurrent cases the dose may be increased to 40 mg omeprazole daily. For patients with a history of recurrent duodenal ulcer, long term therapy is recommended at a dosage of 20 mg omeprazole once daily.
To prevent recurrence, in patients with duodenal ulcer, the recommended dose is omeprazole 10 mg, once daily, increasing to 20 mg, once daily if symptoms return.
The following groups of patients are at risk from recurrent ulcer relapse: those with Helicobacter pylori infection, younger patients (<60 years), those whose symptoms persist for more than one year and smokers. These patients will require initial longterm therapy with omeprazole 20 mg once daily, reducing to 10 mg once daily, if necessary.
Acid-related dyspepsia:
Usual dosage is 10 mg or 20 mg omeprazole once daily for 2 - 4 weeks depending on the severity and persistence of symptoms.
If the patient does not respond to treatment after 4 weeks or who relapse shortly after treatment, then the patient should be investigated.
For the treatment of NSAID-associated gastric ulcers, duodenal ulcers or gastroduodenal erosions:
The recommended dosage of omeprazole is 20 mg once daily. Symptom resolution is rapid and in most patients healing occurs within 4 weeks. For those patients who may not be fully healed after the initial course, healing usually occurs during a further 4 weeks treatment.
For the prophylaxis of NSAID-associated gastric ulcers, duodenal ulcers, gastroduodenal erosions and dyspeptic symptoms in patients with a previous history of gastroduodenal lesions who require continued NSAID treatment:
The recommended dosage is 20 mg omeprazole taken once a day.
Helicobacter pylori (Hp) eradication regimens in peptic ulcer disease:
Omeprazole is recommended at a dose of 40 mg once daily or 20 mg twice daily concomitant with antimicrobial agents as detailed below:
Triple therapy regimens in duodenal ulcer disease:
Omeprazole and the following antimicrobial combinations;
Amoxicillin 500 mg and metronidazole 400 mg both three times a day for one week.
or
Clarithromycin 250 mg and metronidazole 400 mg (or tinidazole 500 mg) both twice a day for one week.
or
Amoxicillin 1 g and clarithromycin 500 mg both twice a day for one week.
Dual therapy regimens in duodenal ulcer disease
Omeprazole and amoxicillin 750 mg to 1 g twice daily for two weeks. Alternatively, omeprazole and clarithromycin 500 mg three times a day for two weeks.
Dual therapy regimens in gastric ulcer disease:
In each regimen if symptoms return and the patient tests positive for Hp, therapy may be repeated or one of the alternative regimens can be used; if the patient is Hp negative then see dosage instructions for acid reflux disease.
To ensure healing in patients with active peptic ulcer disease, see further dosage recommendations for duodenal and benign gastric ulcer.
Prophylaxis of acid aspiration:
For patients considered to be at risk of aspiration of the gastric contents during general anaesthesia, the recommended dosage is omeprazole 40 mg on the evening before surgery followed by a further 40 mg 2 - 6 hours prior to surgery.
Zollinger-Ellison syndrome:
The initial starting dose is omeprazole 60 mg once a day. The dosage should be adjusted individually and treatment continued as long as clinically indicated. More than 90% of patients with severe disease and inadequate response to other therapies have been effectively controlled on doses of 20 - 120 mg daily. With doses above 80 mg daily, the dose should be divided and given twice daily.
Elderly:
Dose adjustment is not required in the elderly.
Children:
There is limited experience of the use of Omeprazole in children. In children over 2 years who present with severe ulcerating reflux oesophagitis, Omeprazole Capsules are recommended for symptomatic relief within the dose range of 0.7 - 1.4 mg/kg daily, to a maximum of 40 mg/day, for 4 - 12 weeks. Data suggest that approximately 65% of children will experience pain relief with this dose regimen.
Treatment should be initiated by a hospital based paediatrician.
For children aged 2 - 6 years, the capsule may be opened, see section: “Patients with Swallowing Difficulties.”
Impaired renal function:
Dose adjustment is not required in patients with impaired renal function.
Impaired hepatic function:
As bioavailability and half-life can increase in patients with impaired hepatic function, the dose requires adjustment with a maximum daily dose of 20 mg.
Patients with swallowing difficulties:
The capsules may be opened and the contents either swallowed alone or suspended in a small amount of fruit juice or yoghurt after gentle mixing. The dispersion should be taken immediately or within 30 minutes. Actual capsules may be sucked and then swallowed. It is important that the contents of the capsules should not be crushed or chewed.
4.3 Contraindications
Hypersensitivity to omeprazole, substituted benzimidazoles, or to any of the other excipients listed in section 6.1
Omeprazole like other proton pump inhibitors (PPIs) must not be used concomitantly with nelfinavir (see section 4.5).
4.4 Special warnings and precautions for use
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.
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.
Omeprazole, as all acid-blocking medicines, may reduce the absorption of vitamin B12 (cyanocobalamin) due to hypo- or achlorhydria. This should be considered in patients with reduced body stores or risk factors for reduced vitamin B12 absorption on long-term therapy.
Omeprazole is a CYP2C19 inhibitor. When starting or ending treatment with omeprazole, the potential for interactions with drugs metabolised through CYP2C19 should be considered. An
interaction is observed between clopidogrel and omeprazole (see section 4.5). The clinical relevance of this interaction is uncertain. As a precaution, concomitant use of omeprazole and clopidogrel should be discouraged.
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. Serious manifestations of hypomagnesaemia such as fatigue, tetany, delirium, convulsions, dizziness and ventricular arrhythmia can occur but they may begin insidiously and be overlooked. In most affected patients, hypomagnesaemia improved after magnesium replacement and discontinuation of the PPI.
For patients expected to be on prolonged treatment or who take PPIs with digoxin or drugs that may cause hypomagnesaemia (e.g. diuretics), health care professionals should consider measuring magnesium levels before starting PPI treatment and periodically during treatment.
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 10-40%. Some of this increase may be due to other risk factors. Patients at risk of osteoporosis should receive care according to current clinical guidelines and they should have an adequate intake of vitamin D and calcium.
Subacute cutaneous lupus erythematosus (SCLE)
Proton pump inhibitors are associated with very infrequent cases of SCLE. If lesions occur, especially in sun-exposed areas of the skin, and if accompanied by arthralgia, the patient should seek medical help promptly and the health care professional should consider stopping Omeprazole. SCLE after previous treatment with a proton pump inhibitor may increase the risk of SCLE with other proton pump inhibitors.
Interference with laboratory tests
Increased Chromogranin A (CgA) level may interfere with investigations for neuroendocrine tumours. To avoid this interference, omeprazole treatment should be stopped for at least 5 days before CgA measurements (see section
5.1) . If CgA and gastrin levels have not returned to reference range after initial measurement, measurements should be repeated 14 days after cessation of proton pump inhibitor treatment.
Some children with chronic illnesses may require long-term treatment although it is not recommended.
This product contains sucrose and therefore patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucraseisomaltase insufficiency should not take this medicine.
Treatment with proton pump inhibitors may lead to slightly increased risk of gastrointestinal infections such as Salmonella and Campylobacter (see section
5.1) .
As in all long-term treatments, especially when exceeding a treatment period of 1 year, patients should be kept under regular surveillance.
4.5 Interaction with other medicinal products and other forms of interaction
Effects of omeprazole on the pharmacokinetics of other active substances
The decreased intragastric acidity during treatment with omeprazole might increase or decrease the absorption of active substances with a gastric pH dependent absorption.
Nelfinavir, atazanavir
The plasma levels of nelfinavir and atazanavir are decreased in case of coadministration with omeprazole.
Concomitant administration of omeprazole with nelfinavir is contraindicated (see section 4.3). Co-administration of omeprazole (40 mg once daily) reduced mean nelvinavir exposure by ca. 40% and the mean exposure of the pharmacologically active metabolite M8 was reduced by ca. 75 -90%. The interaction may also involve CYP2C19 inhibition.
Concomitant administration of omeprazole with atazanavir is not recommended (see section 4.4). Concomitant administration of omeprazole (40 mg once daily) and atazanavir 300 mg/ritonavir 100 mg to healthy volunteers resulted in a 75% decrease of the atazanavir exposure. Increasing the atazanavir dose to 400 mg did not compensate for the impact of omeprazole on atazanavir exposure. The co-administration of omeprazole (20 mg once daily) with atazanavir 400 mg/ritonavir 100 mg to healthy volunteers resulted in a decrease of approximately 30% in the atazanavir exposure as compared to atazanavir 300 mg/ritonavir 100 mg once daily.
Digoxin
Simultaneous treatment with omeprazole and digoxin in healthy subjects lead to a 10% increase in the bioavailability of digoxin as a consequence of the increased intragastric pH. Digoxin toxicity has been rarely reported. However caution should be exercised when omeprazole is given at high doses in elderly patients. Therapeutic drug monitoring of digoxin should be then be reinforced.
Clopidogrel
Results from studies in healthy subjects have shown a pharmacokinetic (PK)/pharmacodynamic (PD) interaction between clopidogrel (300 mg loading dose/75 mg daily maintenance dose) and omeprazole (80 mg p.o. daily) resulting in a decreased exposure to the active metabolite of clopidogrel by an average of 46% and a decreased maximum inhibition of (ADP induced) platelet aggregation by an average of 16%.
Inconsistent data on the clinical implications of a PK/PD interaction of omeprazole in terms of major cardiovascular events have been reported from both observational and clinical studies. As a precaution, concomitant use of omeprazole and clopidogrel should be discouraged (see section 4.4).
Other active substances
The absorption of posaconazole, erlotinib, ketoconazole and itraconazole is significantly reduced and thus clinical efficacy may be impaired. For posaconazole and erlotinib concomitant use should be avoided.
Active substances metabolised by CYP2C19
Omeprazole is a moderate inhibitor of CYP2C19, the major omeprazole metabolising enzyme. Thus, the metabolism of concomitant active substances also metabolised by CYP2C19, may be decreased and the systemic exposure to these substances increased. Examples of such drugs are R-warfarin and other vitamin K antagonists, cilostazol, diazepam and phenytoin.
Cilostazol
Omeprazole, given in doses of 40 mg to healthy subjects in a cross-over study, increased Cmax and AUC for cilostazol by 18% and 26% respectively, and one of its active metabolites by 29% and 69% respectively.
Phenytoin
Monitoring phenytoin plasma concentration is recommended during the first two weeks after initiating omeprazole treatment and, if a phenytoin dose adjustment is made, monitoring and a further dose adjustment should occur upon ending omeprazole treatment.
Unknown mechanism
Saquinavir
Concomitant administration of omeprazole with saquinavir/ritonavir resulted in increased plasma levels up to approximately 70% for saquinavir associated with good tolerability in HIV-infected patients.
Tacrolimus
Concomitant administration of omeprazole has been reported to increase the serum levels of tacrolimus. A reinforced monitoring of tacrolimus concentrations as well as renal function (creatinine clearance) should be performed, and dosage of tacrolimus adjusted if needed.
Methotrexate
When given together with proton-pump inhibitors, methotrexate levels have been reported to increase in some patients. In high-dose methotrexate administration a temporary withdrawal of omeprazole may need to be considered.
Effects of other active substances on the pharmacokinetics of omeprazole Inhibitors CYP2C19 and/or CYP3A4
Since omeprazole is metabolised by CYP2C19 and CYP3A4, active substances known to inhibit CYP2C19 or CYP3A4 (such as clarithromycin and voriconazole) may lead to increased omeprazole serum levels by decreasing omeprazole’s rate of metabolism.-Concomitant voriconazole treatment resulted in more than doubling of the omeprazole exposure. As high doses of omeprazole have been well-tolerated adjustment of the omeprazole dose is not generally required. However, dose adjustment should be considered in patients with severe hepatic impairment and if long-term treatment is indicated.
Inducers of CYP2C19 and/or CYP3A4
Active substances known to induce CYP2C19 or CYP3A4 or both (such as rifampicin and St John’s wort) may lead to decreased omeprazole serum levels by increasing omeprazole’s rate of metabolism.
4.6 Fertility, Pregnancy and lactation
Pregnancy
Results from three prospective epidemiological studies (more than 1000 exposed outcomes) have revealed no evidence of adverse events of omeprazole on pregnancy or on the health of the foetus / newborn child. Omeprazole 20 mg can be used during pregnancy.
Breastfeeding
Omeprazole is excreted into breast milk but is unlikely to influence the child when used in therapeutic doses.
Fertility
Animal studies with the racemic mixture omeprazole, given by oral administration do not indicate effects with respect to fertility.
4.7 Effects on ability to drive and use machines
Omeprazole is not likely to affect the ability to drive or use machines. Adverse drug reactions such as dizziness and visual disturbances may occur (see section 4.8). If affected, patients should not drive or operate machinery.
4.8 Undesirable effects
Summary of the safety profile
The most common side effects (1-10% of patients) are headache, abdominal pain, constipation, diarrhoea, flatulence and nausea/vomiting.
Tabulated list of adverse reactions
The following adverse drug reactions have been identified or suspected in the clinical trials programme for omeprazole and post-marketing. None was found to be dose-related. Adverse reactions listed below are classified according to frequency and System Organ Class (SOC). Frequency categories are defined according to the following convention:
Very common (> 1/10)
Common >1/100 and < 1/10)
Uncommon > 1/1000 and < 1/100 Rare > 1/10,000 and < 1/1000 Very rare (< 1/10,000)
Not known (cannot be estimated from the available data).
SOC/frequency |
Adverse reaction |
Blood and lymphatic system disorders | |
Rare: |
Leukopenia, thrombocytopenia |
Very rare: |
Agranulocytosis, pancytopenia |
Immune system disorders | |
Rare: |
Hypersensitivity reactions e.g. fever, angioedema and anaphylactic reaction/shock |
Metabolism and nutrition disorders | |
Rare: |
Hyponatraemia |
Not known: |
Hypomagnesaemia; severe hypomagnesaemia may result in hypocalcaemia. Hypomagnesaemia may also be associated with hypokalaemia. |
Psychiatric disorders | |
Uncommon: |
Insomnia |
Rare: |
Agitation, confusion, depression |
Very rare: |
Aggression, hallucinations |
Nervous system disorders | |
Common: |
Headache |
Uncommon: |
Dizziness, paraesthesia, somnolence |
Rare: |
Taste disturbance |
Eye disorders | |
Rare: |
Blurred vision |
Ear and labyrinth disorders | |
Uncommon: |
Vertigo |
Respiratory, thoracic and mediastinal disorders | |
Rare: |
Bronchospasm |
Gastrointestinal disorders | |
Common: |
Abdominal pain, constipation, diarrhoea, flatulence, nausea/vomiting |
Rare: |
Dry mouth, stomatitis, gastrointestinal candidiasis |
Not known: |
Microscopic colitis |
Hepatobiliary disorders | |
Uncommon: |
Increased liver enzymes |
Rare: |
Hepatitis with or without jaundice |
Very rare: |
Hepatic failure, encephalopathy in patients with preexisting liver disease |
Skin and subcutaneous tissue disorders | |
Uncommon: |
Dermatitis, pruritus, rash, urticaria |
Rare: |
Alopecia, photosensitivity |
Very rare: |
Erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN) |
Not known: |
Subacute cutaneous lupus erythematosus (see section 4.4) |
Musculoskeletal and connective tissue disorders | |
Uncommon: |
Fracture of the hip, wrist or spine |
Rare: |
Arthralgia, myalgia |
Very rare: |
Muscular weakness |
Renal and urinary disorders | |
Rare: |
Interstitial nephritis |
Reproductive system and breast disorders | |
Very rare: |
Gynaecomastia |
General disorders and administration site conditions | |
Uncommon: |
Malaise, peripheral oedema |
Rare: |
Increased sweating |
Paediatric population
The safety of omeprazole has been assessed in a total of 310 children aged 0 to 16 years with acid-related disease. There are limited long term safety data from 46 children who received maintenance therapy of omeprazole during a clinical study for severe erosive oesophagitis for up to 749 days. The adverse event profile was generally the same as for adults in short- as well as in longterm treatment. There are no long term data regarding the effects of omeprazole treatment on puberty and growth.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme website: www.mhra.gov.uk/yellowcard
4.9 Overdose
Rare reports have been received of overdosage with omeprazole. Doses of up to 560 mg have been described and occasional reports have been received when single oral doses have been reached up to 2400 mg, which is 120 times the recommended clinical dose. Overdosage of omeprazole is reported to be associated with nausea, vomiting, dizziness, abdominal pain, diarrhoea and headache. Single cases of apathy, depression and confusion have been described.
The symptoms described in connection with omeprazole overdosage have been transient and no serious outcome has been reported. The rate of elimination was unchanged (first order kinetics) with increased doses and no specific treatment is needed.
5.1 Pharmacodynamic properties
ATC code: A02B C01 - Drugs for peptic ulcers and gastro-oesophageal reflux disease
- Proton Pump inhibitors.
Mechanism of action
Omeprazole, a racemic mixture of two enantiomers reduces gastric acid secretion through a highly targeted mechanism of action. It is a specific inhibitor of the acid pump in the parietal cell. It is rapidly acting and provides control through reversible inhibition of gastric acid secretion with once daily dosing.
Omeprazole is a weak base and is concentrated and converted to the active form in the highly acidic environment of the intracellular canaliculi within the parietal cell, where it inhibits the enzyme H+ K+-ATPase - the proton pump. This effect on the final step of the gastric acid formation process is dose-dependent and provides for highly effective inhibition of both basal acid secretion and stimulated acid secretion, irrespective of stimulus. Pharmacodynamic effects
All pharmacodynamic effects observed are explained by the effect of omeprazole on acid secretion.
Effect on gastric acid secretion
Oral dosing with omeprazole once daily provides for rapid and effective inhibition of daytime and night-time gastric acid secretion with maximum effect being achieved within 4 days of treatment. With omeprazole 20 mg, a mean decrease of at least 80% in 24-hour intragastric acidity is then maintained in duodenal ulcer patients, with the mean decrease in peak acid output after pentagastrin stimulation being about 70% 24 hours after dosing. Oral dosing with omeprazole 20 mg maintains an intragastric pH of > 3 for a mean time of 17 hours of the 24-hour period in duodenal ulcer patients.
As a consequence of reduced acid secretion and intragastric acidity, omeprazole dose-dependently reduces/normalizes acid exposure of the oesophagus in patients with gastro-oesophageal reflux disease. The inhibition of acid secretion is related to the area under the plasma concentration-time
curve (AUC) of omeprazole and not to the actual plasma concentration at a given time. No tachyphylaxis has been observed during treatment with omeprazole.
Effects on H. pylori
Hpylori is associated with peptic ulcer disease including duodenal and gastric ulcer disease. H.pylori is a major factor in the development of atrophic gastritis which is associated with an increased risk of developing gastric cancer.
Eradication of H. pylori with omeprazole and antimicrobials is associated with, high rates of healing and long-term remission of peptic ulcers.
Dual therapies have been tested and found to be less effective than triple therapies. They could, however, be considered in cases where known hypersensitivity precludes use of any triple combination.
Other effects related to acid inhibition
During long-term treatment an increased frequency of gastric glandular cysts has been reported. These changes are a physiological consequence of pronounced inhibition of acid secretion. The cysts are benign and appear to be reversible.
Decreased gastric acidity due to any means including proton pump inhibitors, increases gastric counts of bacteria normally present in the gastrointestinal tract. Treatment with acid-reducing drugs may lead to slightly increased risk of gastrointestinal infections such as Salmonella and Campylobacter.
During treatment with antisecretory medicinal products serum gastrin increases in response to the decreased acid secretion. Also CgA increases due to decreased gastric acidity. The increased CgA level may interfere with investigations for neuroendocrine tumours.
Available published evidence suggests that proton pump inhibitors should be discontinued between 5 days and 2 weeks prior to CgA measurements. This is to allow CgA levels that might be spuriously elevated following PPI treatment to return to reference range.
An increased number of ECL cells possibly related to the increased serum gastrin levels, have been observed in some patients (both children and adults) during long term treatment with omeprazole. The findings are considered to be of no clinical significance.
Paediatric population
In a non-controlled study in children (1 to 16 years of age) with severe reflux oesophagitis, omeprazole at doses of 0.7 to 1.4 mg/kg improved oesophagitis level in 90% of the cases and significantly reduced reflux symptoms. In a single-blind study, children aged 0-24 months with clinically diagnosed gastro-oesophageal reflux disease were treated with 0.5, 1.0 or 1.5 mg omeprazole/kg. The frequency of vomiting/regurgitation episodes decreased by 50% after 8 weeks of treatment irrespective of the dose.
Eradication of H. pylori in children
A randomised, double blind clinical study (Heliot study) concluded that omeprazole in combination with two antibiotics (amoxicillin and clarithromycin), was safe and effective in the treatment of H. pylori infection in children age 4 years old and above with gastritis: H. pylori eradication rate: 74.2% (23/31 patients) with omeprazole + amoxicillin + clarithromycin versus 9.4% (3/32 patients) with amoxicillin + clarithromycin. However, there was no evidence of any clinical benefit with respect to dyspeptic symptoms. This study does not support any information for children aged less than 4 years.
5.2 Pharmacokinetic properties
Absorption
Omeprazole is acid labile and is administered orally as enteric-coated granules in capsules. . Absorption of omeprazole is rapid, with peak plasma levels occurring approximately 1-2 hours after dose. Absorption takes place in the small intestine and is usually completed within 3 - 6 hours. Concomitant intake of food has no influence on the bioavailability. The systemic availability (bioavailability) of omeprazole from a single oral dose is approximately 40%. After repeated once-daily administration, the bioavailability increases to about 60%.
Distribution
The apparent volume of distribution in healthy subjects is approximately 0.3 l/kg body weight. Omeprazole is 97% plasma protein bound.
Biotransformation
Omeprazole is completely metabolised by the cytochrome P450 system (CYP). The major part of its metabolism is dependent on the polymorphically expressed CYP2C19, responsible for the formation of hydroxyomeprazole, the major metabolite in plasma. The remaining part is dependent on another specific isoform, CYP3A4, responsible for the formation of omeprazole sulfone. As a consequence of high affinity of omeprazole to CYP2C19, there is a potential for competitive inhibition and metabolic drug-drug interactions with other substrates for CYP2C19. However, due to low affinity to CYP3A4, omeprazole has no potential to inhibit the metabolism of other CYP3A4 substrates. In addition, omeprazole lacks an inhibitory effect on the main CYP enzymes.
Approximately 3% of the Caucasian population and 15-20% of Asian populations lack a functional CYP2C19 enzyme and are called poor metabolisers. In such individuals the metabolism of omeprazole is probably mainly catalysed by CYP3A4. After repeated once-daily administration of 20 mg omeprazole, the mean AUC was 5 to 10 times higher in poor metabolisers than in subjects having a functional CYP2C19 enzyme (extensive metabolisers). Mean peak plasma concentrations were also higher, by 3 to 5 times. These findings have no implications for the posology of omeprazole.
Elimination
The plasma elimination half-life of omeprazole is usually shorter than one hour both after single and repeated oral once-daily dosing. Omeprazole is completely eliminated from plasma between doses with no tendency for accumulation during once-daily administration. Almost 80% of an oral dose of omeprazole is excreted as metabolites in the urine, the remainder in the faeces, primarily originating from bile secretion.
Linearity/non-linearity
The AUC of omeprazole increases with repeated administration. This increase is dose-dependent and results in a non-linear dose-AUC relationship after repeated administration. This time- and dose-dependency is due to a decrease of first pass metabolism and systemic clearance probably caused by an inhibition of the CYP2C19 enzyme by omeprazole and/or its metabolites (e.g. the sulfone).
No metabolite has been found to have any effect on gastric acid secretion.
Special populations Hepatic impairment
The metabolism of omeprazole in patients with liver dysfunction is impaired, resulting in an increased AUC. Omeprazole has not shown any tendency to accumulate with once daily dosing.
Renal impairment
The pharmacokinetics of omeprazole, including systemic bioavailability and elimination rate, are unchanged in patients with reduced renal function. Elderly
The metabolism rate of omeprazole is somewhat reduced in elderly subjects (75-79 years of age).
Paediatric population
During treatment with the recommended doses to children from the age of 1 year, similar plasma concentrations were obtained as compared to adults. In children younger than 6 months, clearance of omeprazole is low due to low capacity to metabolise omeprazole
5.3 Preclinical safety data
Gastric ECL-cell hyperplasia and carcinoids, have been observed in life-long studies in rats treated with omeprazole. These changes are the result of sustained hypergastrinaemia secondary to acid inhibition, Similar findings have been made after treatment with H2-receptor antagonists, proton pump inhibitors and after partial fundectomy. Thus, these changes are not from a direct effect of any individual active substance.
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Sugar spheres Sodium starch glycolate Sodium laurilsulfate Povidone Potassium oleate Oleic Acid
Hypromellose
Methacrylic acid - ethyl acrylate (1:1) Triethyl citrate Titanium dioxide Talc
Capsule
Gelatin
Titanium dioxide (E171)
Quinoline yellow (E104)
Indigo carmine (E132)
Erythrosine (E127)
Printing Ink Shellac
Polyvinylpyrrolidone Propylene glycol Sodium Hydroxide Titanium Dioxide (E171)
Propylene Glycol
6.2 Incompatibilities
Not applicable.
6.3 Shelf life
3 years
6.4 Special precautions for storage
Do not store above 30°C. Store in the original package. Keep the bottle tightly closed.
Nature and contents of container
6.5
HDPE bottle and polypropylene cap with integral silica gel dessicant
HDPE bottle and child-resistant polypropylene cap with integral silica gel dessicant
Each pack contains 28 capsules.
6.6 Special precautions for disposal
No special instructions.
7 MARKETING AUTHORISATION HOLDER
Medley Pharma Limited Unit 2A,
Olympic Way Sefton Business Park Liverpool L30 1RD UK
8 MARKETING AUTHORISATION NUMBER(S)
PL 43870/0014
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION 4 August 2010
10 DATE OF REVISION OF THE TEXT
02/11/2016