Summary of Product Characteristics (SmPC) - Sodium Bicarbonate 500 mg capsules, hard
1 NAME OF THE MEDICINAL PRODUCT
Sodium Bicarbonate 500 mg Capsules, Hard
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each capsule contains 500 mg of Sodium Bicarbonate (equivalent to 137mg of sodium).
For the full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
Capsule, hard. (Capsule)
Empty hard gelatin capsule shell, size “1”, clear transparent cap and body, imprinted with SB on Cap and 500 on body, containing white to off-white granular powder or powder plug.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Sodium Bicarbonate is intended for the treatment of dyspepsia. It may also be used to treat metabolic acidosis arising from a variety of disorders as well as severe respiratory acidosis. The dosage must be calculated on an individual basis and is dependent on the acid-base balance and electrolyte status of the patient.
4.2 Posology and method of administration
Adults
Dyspepsia: 1g – 5g when required
Metabolic Acidosis: The dosage is dependent upon the acid-base balance and electrolyte status of the patient and must be calculated on an individual basis.
Paediatric population
Not recommended.
Method of administration
For oral administration. To be swallowed whole with a drink of water.
4.3 Contraindications
Patients with hypersensitivity to sodium bicarbonate or any ingredient of the formulation.
Contraindicated in patients with metabolic alkalosis or respiratory alkalosis, hypokalaemia, hypernatraemia, low sodium diet, hypocalcaemia, or hypochlorhydria.
Not to be taken by children under 12 years old.
4.4 Special warnings and precautions for use
Overtreatment with bicarbonate must be avoided. Frequent monitoring of serum electrolytes and acid-base status is essential. In patients with moderate and advanced chronic renal disease, the association between serum bicarbonate concentration and all-cause mortality is U-shaped. The lowest mortality rate is seen in patients with serum bicarbonate concentration in the range of 26–29 mmol/l. The highest mortality rate is observed among patients with serum bicarbonate levels of < 22 mmol/l but an increase in mortality is also seen in patients with serum bicarbonate levels of > 29 mmol/l.
Sodium bicarbonate should be given extremely cautiously to patients with heart failure, oedema, renal impairment, hypertension, eclampsia, aldosteronism, or other conditions associated with sodium retention.
Do not take if you are hypersensitive to sodium bicarbonate.
Consult your doctor or pharmacist if symptoms persist after 7 days.
This medicine can mask the symptoms of stomach cancer or ulcer.
4.5 Interaction with other medicinal products and other forms of interaction
The effects of a number of drugs may be reduced or increased by the alkalinisation of the urine (e.g. aspirin or diflunisal) and changes in gastric pH brought about by sodium bicarbonate.
In particular cases elimination of weak acids and bases may be affected by sodium hydrogen carbonate treatment via an increase of the pH in urine. This might for example apply to sympathomimetics, anticholinergics, tricyclic antidepressants, barbiturates, H2-blockers, captopril, and quinidine.
Sodium-containing preparations should be avoided by patients on lithium because sodium is preferentially absorbed by the kidney resulting in increased lithium excretion and reduced plasma levels.
As a precaution for antacids, in order to minimise the risk of interactions affecting pharmacokinetics of concomitantly administered products, drug administrations should be separated by approximately 2 to 3 hours.
Large amounts of milk or calcium containing products should not be taken whilst taking Sodium bicarbonate capsules. Such administration may result in milk-alkali syndrome.
Sodium bicarbonate reduces the absorption of a number of other drugs taken concomitantly. These include ACE inhibitors (captopril, enalapril, and fosinapril), antibacterials and antifungals (azithromycin, cefaclor, cefpodoxime, isoniazid, itraconazole, rifampicin, tetracyclines, ketoconazole and the quinolone group of antibacterials); antivirals (atazanivir, fosamprenavir, tipranavir); antihistamines (fexofenadine); bisphosponates, corticosteroids (deflazacort); digoxin, dipyridamole, antiepileptics (gabapentin and phenytoin), ulcer healing drugs (lansoprazole); levothyroxine, mycophenolate, lipid regulating drugs (rosuvastatin); antipsychotics (sulpiride, phenothiazines), chloroquine, hydrochloroquine, and penicillamine. Antacids should be avoided with nilotinib.
Functional interactions with gluco- and mineralocorticoids, androgens and diuretics associated with increased potassium excretion may occur.
Antacids possibly reduce absorption of bile acids.
4.6 Fertility, pregnancy and lactation
Pregnancy
Animal studies are insufficient with respect to effects on pregnancy, embryonal fetal development, parturition and postnatal development. The potential risk for humans is unknown. Sodium bicarbonate should not be taken during pregnancy unless advised by a doctor to do so.
Breast-feeding
The effects of sodium administration during breast-feeding are not known. Sodium bicarbonate should not be taken if breast-feeding unless advised by a doctor to do so.
Fertility
The potential risks of sodium on fertility are not known.
4.7 Effects on ability to drive and use machines
None known.
4.8 Undesirable effects
General adverse effects of sodium bicarbonate are as follows. The following adverse reactions are classified by system organ class and ranked under heading of frequency using the following convention: very common (≥ 10%), common (≥ 1% and < 10%); uncommon (≥ 0.1% and < 1%); rare (≥ 0.01% and < 0.1%), very rare (< 0.01%), not known (cannot be estimated from the available data).
| stem Organ Class | Frequency | Adverse reactions |
| Gastrointestinal disorders | Not known | Wind, Nausea, Vomiting, Abdominal Discomfort, Abdominal distension, Flatulence, Unpleasant taste |
| Metabolism & nutrition disorders | Not known | Metabolic alkalosis, Fluid retention, Loss of appetite (continuing) |
| Psychiatric disorders: | Not known | Mood or mental changes, Nervousness or restlessness |
| Vascular disorders: | Not known | Hypertension, Slow breathing, Breathing difficulties, Fluid on the lungs |
| Nervous system disorders: | Not known | Headache (continuing), Dizziness |
Skin and subcutaneous tissue disorders: | Not known | Swelling of feet of lower legs |
| Renal and urinary disorders: | Not known | Frequent urge to urinate, Promotion of renal urolithiasis (formation of calcium or magnesium phosphate calculi) upon prolonged use. |
General disorders and administration site conditions: | Not known | Extreme irritability, unusual tiredness or weakness, muscle spasms or cramps |
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 at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store
4.9 Overdose
Excessive administration of bicarbonate may lead to hypokalaemia and metabolic alkalosis, especially in patients with impaired renal function. Symptoms include mood changes, tiredness, shortness of breath, muscle weakness and irregular heartbeat. Muscle hypertonicity, twitching and tetany may develop, especially in hypocalcaemic patients. Excessive doses of sodium salts may lead to sodium overloading and hyperosmolality.
Treatment of metabolic alkalosis and hypernatraemia is by correction of fluid and electrolyte balance. Replacement of calcium, chloride, and potassium ions may be of particular importance.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
ATC code: A02AH Antacids with Sodium Bicarbonate.
Sodium bicarbonate is used as an antacid in relief of the symptoms of dyspepsia, heartburn and indigestion caused by excess gastrointestinal acid. Sodium bicarbonate causes neutralisation of gastric acid with the production of carbon dioxide. Sodium bicarbonate therapy increases plasma bicarbonate, buffers excess hydrogen ion concentration, raises blood pH and reverses clinical manifestations of metabolic acidosis.
5.2 Pharmacokinetic properties
Absorption
Sodium bicarbonate is readily absorbed from the gastro-intestinal tract.
Sodium bicarbonate exists as a sodium ion and bicarbonate ion within Sodium bicarbonate capsules. Once orally administered, the bicarbonate ion readily binds to hydrochloric acid in the stomach to form sodium chloride, carbon dioxide and water.
Bicarbonate ions which do not react with hydrochloric acid within the stomach are readily emptied into the duodenum via the pylorus. Bicarbonate ions are then readily absorbed through the small intestine where they enter general circulation. A linear dose dependent relationship between sodium bicarbonate supplementation and serum bicarbonate levels has been shown in CKD patients with metabolic acidosis.
Distribution
Sodium bicarbonate is present in all body fluids. Sodium bicarbonate causes neutralisation of gastric acid with the production of carbon dioxide.
The bicarbonate ion is freely soluble in the blood stream and readily crosses the blood brain barrier. The site of action of bicarbonate ions with respect to metabolic acidosis is the blood stream.
Biotransformation
The bicarbonate ion is a simple electrolyte and is therefore not hepatically metabolised but rather eliminated from the body via excretion.
Elimination
Any bicarbonate not involved in the gastric acid neutralisation reaction is absorbed. The bicarbonate ion is excreted through various bodily pathways. Firstly, sodium bicarbonate is excreted via the pulmonary system. This involves the bicarbonate ion binding with a free hydrogen ion to form carbonic acid which is then broken down into carbon dioxide and water in the presence of carbonic anhydrase and excreted through the lungs. Bicarbonate ions readily pass through the renal cortex and are eliminated via urine
5.3 Preclinical safety data
There are no pre-clinical data of relevance to the prescriber which are additional to that already included in other sections of the SPC.
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Microcrystalline Cellulose
Magnesium Stearate
Capsule shell:
Gelatin
Sodium laurilsulfate
Printing ink:
Shellac (E904)
Black Iron Oxide (E172)
Propylene Glycol (E1520)
6.2 Incompatibilities
Not applicable.
6.3 Shelf life
24 months
6.4 Special precautions for storage
Store in the original package in order to protect from moisture.
6.5 Nature and contents of container
This product is available in cartons containing Aluminium- PVC or Aluminium PVC/PVDC white opaque blister packs of 56 capsules.
6.6 Special precautions for disposal
No special requirements.
7 MARKETING AUTHORISATION HOLDER
Flamingo Pharma UK Ltd.
1st floor, Kirkland House,
11-15 Peterborough Road,
Harrow, Middlesex,
HA1 2AX, United Kingdom.
8 MARKETING AUTHORISATION NUMBER(S)
PL 43461/0113
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE
AUTHORISATION
07/04/2025
10 DATE OF REVISION OF THE TEXT
07/04/2025