This information is intended for use by health professionals

1. Name of the medicinal product

Thamicarb™ 84mg/ml Oral Solution

2. Qualitative and quantitative composition

Each 1 ml of solution contains 84mg of sodium bicarbonate (equivalent to 1mmol/ml sodium and bicarbonate).

For the full list of excipients, see section 6.1.

3. Pharmaceutical form

Oral solution.

A clear, colourless solution.

4. Clinical particulars
4.1 Therapeutic indications

Thamicarb is used to treat hyperacidity, dyspepsia and symptomatic relief of heartburn and peptic ulceration.

Thamicarb is also indicated for the treatment of metabolic acidosis in adults with chronic kidney disease.

4.2 Posology and method of administration


For acid indigestion

Adults and children over 12 years:

Take 12ml (1g) to 60ml (5g) every 4 to 6 hours.

Not recommended for use in children under 12 years of age.

For metabolic acidosis in chronic kidney disease

Adults (including elderly)

Metabolic Acidosis : Dosage is calculated on an individual basis and administered according to the acid-base balance and electrolyte status.


There is no experience using Thamicarb in the management of metabolic acidosis in children.

Method of administration

The required dose should be drawn from the container into the graduated syringe using the syringe adaptor (see section 6.6).

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 Thamicarb. 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


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.


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.


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).

MedDRA System Organ Class

Adverse Reaction

Gastrointestinal disorders:

Frequency not known

Wind, Nausea, Vomiting, Abdominal Discomfort, Abdominal distension, Flatulence, Unpleasant taste

Metabolism and nutrition disorders:

Frequency not known

Metabolic alkalosis, Fluid retention, Loss of appetite (continuing)

Psychiatric disorders:

Frequency not known

Mood or mental changes, Nervousness or restlessness

Vascular disorders:

Frequency not known

Hypertension, Slow breathing, Breathing difficulties, Fluid on the lungs

Nervous system disorders:

Frequency not known

Headache (continuing), Dizziness

Skin and subcutaneous tissue disorders:

Frequency not known

Swelling of feet of lower legs

Renal and urinary disorders:

Frequency 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:

Frequency 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: 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 heart beat. 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: A02A H, 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


Sodium bicarbonate is readily absorbed from the gastro-intestinal tract.

Sodium bicarbonate exists as a sodium ion and bicarbonate ion within Thamicarb 84mg/ml Oral Solution. 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.


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.


The bicarbonate ion is a simple electrolyte and is therefore not hepatically metabolised but rather eliminated from the body via excretion.


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

No further relevant information.

6. Pharmaceutical particulars
6.1 List of excipients

Purified water

6.2 Incompatibilities

Not Applicable.

6.3 Shelf life

12 months.

For 100ml bottle: Discard your medicine 3 days after first opening.

For 500ml bottle: Discard your medicine 7 days after first opening.

6.4 Special precautions for storage

Do not store above 25°C.

Do not refrigerate or freeze.

Do not use if crystals are observed in the product.

For storage conditions after first opening of the medicinal product, see section 6.3.

6.5 Nature and contents of container

Bottle: Amber glass

Closure: White tamper-evident child-resistant polypropylene cap with HDPE-EPE wadding.

Pack size: 100ml or 500ml

Dosing Device: 20ml white polypropylene oral syringe with 1ml graduation marks and LDPE syringe adaptor

6.6 Special precautions for disposal and other handling

The required dose should be drawn from the container into the graduated syringe provided using the syringe adaptor (see detailed instructions below). The syringe should be held into the mouth of the patient, and the contents of the syringe should then be ejected into the mouth and swallowed.

Instructions for the use of syringe:

a) Open the bottle: press the cap and turn it anticlockwise (figure 1).

b) Separate the adaptor from the syringe (figure 2). Insert the adaptor into the bottle neck (figure 3). Ensure it is properly fixed. Take the syringe and put it in the adaptor opening (figure 4).

c) Turn the bottle upside down. Fill the syringe with a small amount of solution by pulling the piston down (figure 5A), then push the piston upwards in order to remove any possible bubble (figure 5B). Pull the piston down to the graduation mark corresponding to the quantity in millilitres (ml) prescribed by your doctor (figure 5C).

d) Turn the bottle the right way up (figure 6A). Remove the syringe from the adaptor (figure 6B).

e) Empty the contents of the syringe into the patient's mouth by pushing the piston to the bottom of the syringe (figure 7). The contents of the syringe should be emptied into the side cheek of the patients mouth to avoid a choking hazard. Close the bottle with the plastic screw cap. Wash the syringe with water (figure 8).

7. Marketing authorisation holder

Syri Limited

Unit 4, Bradfield Road,

Ruislip, Middlesex,

HA4 0NU, UK.

Trading as:

Thame Laboratories

Unit 4, Bradfield Road,

Ruislip, Middlesex,

HA4 0NU, UK.


Trading as:


Unit 4, Bradfield Road,

Ruislip, Middlesex,

HA4 0NU, UK.

8. Marketing authorisation number(s)

PL 39307/0005

9. Date of first authorisation/renewal of the authorisation

Date of First Authorisation: 29/09/2014

10. Date of revision of the text