Sodium hydrogen carbonate at a glance
Medicine class
Antacid and systemic alkalinising agent
Main roles
Relief of acid indigestion and correction of selected acid–base disturbances
Sodium content
Can add a substantial sodium load, particularly during prolonged or systemic treatment
What is Sodium hydrogen carbonate used for?
Licensed uses vary substantially between formulations.
Oral formulations: relief of dyspepsia, heartburn or indigestion.
Oral formulations: treatment of metabolic acidosis; the gastro-resistant product is specifically licensed for treatment and prevention of recurrent metabolic acidosis in adults with chronic renal impairment.
Injection: selected emergencies involving pre-existing metabolic acidosis, life-threatening hyperkalaemia or tricyclic antidepressant overdose, after appropriate resuscitative measures.
Infusion: correction of metabolic acidosis and urine alkalinisation in selected poisonings, haemolysis or to improve urinary solubility of certain medicines.
Powder: external relief of symptoms from insect bites and sunburn.
How does Sodium hydrogen carbonate work?
Bicarbonate neutralises hydrogen ions. In the stomach, this reduces acidity and produces carbon dioxide and water. After absorption or intravenous administration, it increases the body’s bicarbonate buffer and raises pH. It also makes urine more alkaline, altering the solubility and elimination of some substances.
Sodium hydrogen carbonate preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 8.4% w/v
Capsule
Route: Oral
Strengths: 500 mg
Gastro-resistant capsule
Route: Oral
Strengths: 500 mg
Oral solution
Route: Oral
Strengths: 84 mg/mL
How to take Sodium hydrogen carbonate
Follow the instructions for the exact formulation because administration differs.
Swallow standard capsules whole with water.
Swallow gastro-resistant capsules whole with sufficient liquid. Do not chew or open them because this destroys the coating.
Measure oral solution using the supplied oral syringe, placing it against the inside of the cheek and pressing the plunger slowly. Wash and dry the syringe afterwards.
Dissolve powder intended for oral use in water as directed on its label. Do not confuse oral and external-use instructions.
Avoid taking large amounts of milk or calcium products with oral capsules.
Injection and infusion formulations are administered and monitored by healthcare professionals.
Sodium hydrogen carbonate side effects
Common or expected effects
- Wind, belching or abdominal bloating
- Stomach discomfort or cramps
- Nausea or vomiting
- Unpleasant taste
Get urgent medical advice
- Fluid retention, ankle swelling, raised blood pressure or breathlessness
- Metabolic alkalosis or electrolyte disturbance, potentially causing confusion, marked weakness, cramps, twitching or an irregular heartbeat
- Severe sodium overload, potentially causing agitation, seizures or coma
- Rare allergic reactions to formulation ingredients, including soya in gastro-resistant capsules
- Tissue injury if concentrated intravenous solution escapes outside the vein
Sodium hydrogen carbonate in pregnancy
Do not self-treat during pregnancy without advice from a pharmacist, midwife or prescriber. Pregnancy data are limited, and systemic absorption and sodium loading may be important, especially with hypertension, pre-eclampsia, heart disease or kidney disease. Check the specific product.
Sodium hydrogen carbonate interactions
Interactions depend on the formulation and clinical context because sodium hydrogen carbonate changes gastric and urinary pH and adds sodium.
Lithium
Increased urinary lithium elimination may reduce lithium concentrations and treatment effect.
Antibacterials, antifungals and other pH-sensitive oral medicines
Absorption may be reduced. Examples include tetracyclines, quinolones, azole antifungals, levothyroxine, bisphosphonates and mycophenolate; check timing with a pharmacist.
Common questions about Sodium hydrogen carbonate
Answers are fully visible for fast scanning and source review.
Is sodium hydrogen carbonate the same as sodium bicarbonate?
Yes. They are two names for the same active substance.
Can it relieve heartburn?
Some oral products relieve heartburn, indigestion or dyspepsia by neutralising stomach acid. Persistent symptoms need assessment rather than prolonged self-treatment.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.