Sodium Bicarbonate

Sodium bicarbonate is a source of bicarbonate used for systemic or urinary alkalinization. Veterinary applications include selected severe metabolic acidosis and specific electrolyte or toxicologic emergencies. Oral preparations also provide alkali for some chronic disorders. Its clinical role is replacement or provision of buffering capacity when that is an appropriate treatment objective.

Group

Systemic and urinary alkalinizer

Mechanism of Action

Bicarbonate combines with hydrogen ions to form carbonic acid, which dissociates into water and carbon dioxide. Removal of carbon dioxide through ventilation contributes to the net buffering effect. Increased bicarbonate availability raises extracellular buffering capacity and can increase urinary pH. Changes in acid–base status can also promote intracellular potassium redistribution in selected acidemic patients.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Metabolic acidosis	0.5–1 mEq/kg	IV		Individualize from measured acid-base status.
Urinary alkalinization	50 mg/kg	PO	Every 8–12 h
Oral antacid	2–5 g/animal	PO		Mix with water; other agents suppress acid more effectively.
Cardiopulmonary resuscitation — Initial	1 mEq/kg	IV	Once
Cardiopulmonary resuscitation — Maintenance	0.5 mEq/kg	IV	Every 0.1666666667 h	Additional doses every 10 minutes in the reported guidance; use only when clinically indicated.
Severe uremic metabolic acidosis	1–2 mEq/kg	IV		Slow administration when severe acidemia is suspected and blood gases unavailable; treat cause and reassess after buffering/distribution.
Hyperkalemic crisis adjunct	1–2 mEq/kg	IV		Slow administration; ventilation and electrolyte monitoring required.
Hyperkalemic crisis with impaired perfusion	2–3 mEq/kg	IV		Over 30 minutes in a reported non-DKA rescue protocol; individualize.
Urate urolith alkalinization	0.1–0.2 g/kg	PO	Every 8 h	Equivalent to 0.5-1 g per 5 kg; titrate urine pH around 7-7.5.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Metabolic acidosis	0.5–1 mEq/kg	IV		Individualize from measured acid-base status.
Urinary alkalinization	50 mg/kg	PO	Every 8–12 h
Oral antacid	2–5 g/animal	PO		Mix with water; other agents suppress acid more effectively.
Cardiopulmonary resuscitation — Initial	1 mEq/kg	IV	Once
Cardiopulmonary resuscitation — Maintenance	0.5 mEq/kg	IV	Every 0.1666666667 h	Additional doses every 10 minutes in the reported guidance; use only when clinically indicated.
Severe uremic metabolic acidosis	1–2 mEq/kg	IV		Slow administration when severe acidemia is suspected and blood gases unavailable; treat cause and reassess after buffering/distribution.
Hyperkalemic crisis adjunct	1–2 mEq/kg	IV		Slow administration; ventilation and electrolyte monitoring required.
Hyperkalemic crisis with impaired perfusion	2–3 mEq/kg	IV		Over 30 minutes in a reported non-DKA rescue protocol; individualize.

Large_animals

Use / stage	Dose	Route	Schedule	Instructions
Metabolic acidosis	0.5–1 mEq/kg	IV		Slow administration; subsequent amounts based on base deficit.

Horses

Use / stage	Dose	Route	Schedule	Instructions
Oral alkalinization	10–12 g/animal	PO		Adult animals.
Oral alkalinization	2–5 g/animal	PO		Foals, calves or pigs, respectively.

Cattle

Use / stage	Dose	Route	Schedule	Instructions
Oral alkalinization	10–12 g/animal	PO		Adult animals.
Oral alkalinization	2–5 g/animal	PO		Foals, calves or pigs, respectively.

Pigs

Use / stage	Dose	Route	Schedule	Instructions
Oral alkalinization	2–5 g/animal	PO		Foals, calves or pigs, respectively.

Indications

Correction of selected clinically important metabolic acidosis in veterinary patients.
Adjunctive management of selected hyperkalemic emergencies when concurrent metabolic acidosis supports alkali treatment.
Urinary alkalinization within selected urolith or toxin-specific treatment plans.
Selected resuscitation situations involving a defined bicarbonate-responsive disorder, such as documented severe metabolic acidosis or certain sodium-channel-blocker toxicities.

Contraindications

Alkalosis
Hypocalcemia
Excessive chloride loss from vomiting

Interactions

Incompatible with calcium-containing fluids and many acidic/HCl drugs; oral doses can alter other drug absorption.

Adverse effects

Hypernatremia, hyperosmolality, hypokalemia and paradoxical intracellular/CNS acidosis.

Toxicity

Excess or rapid administration can cause alkalosis, tetany, sodium/osmotic loading and electrolyte shifts. Stop supplementation and treat measured acid-base/electrolyte abnormalities.

Preparations

Preparation	Form	Strength	Route
Sodium Bicarbonate 325 mg	Tablet	325 mg / tablet	PO
Sodium Bicarbonate 520 mg	Tablet	520 mg / tablet	PO
Sodium Bicarbonate 650 mg	Tablet	650 mg / tablet	PO
Sodium bicarbonate 4.2% injection Amount expressed as bicarbonate equivalent.	Injection	0.5 mEq / mL	IV
Sodium bicarbonate 8.4% injection Amount expressed as bicarbonate equivalent.	Injection	1 mEq / mL	IV

Monitoring and Administration

Use blood gases and base deficit to guide replacement: mEq requirement = kg x base deficit x 0.3, or factor 0.5 for calves/neonates. Give 25-50% initially over 20-30 minutes and reassess.

Ensure ventilation and monitor sodium, potassium and acid-base status; do not directly mix with calcium-containing fluid.

Additional deficit calculation: 0.5 x kg x (desired minus measured total CO2); give half over 3-4 hours then reassess. DKA example: kg x 0.4 x (12 minus measured bicarbonate) x 0.5 over 6 hours when bicarbonate is 11 mEq/L or less. DKA bicarbonate benefit is controversial; risks include hypokalemia, oxygen-unloading impairment and CNS acidosis. Do not administer during inadequately ventilated CPR.

Ruminant total replacement report is 2-5 mEq/kg over 4-8 hours, not that amount each hour. Severe acidotic calves have received isotonic 156 mEq/L fluid, often 2 L over 1-2 hours followed by further individualized replacement. Formula, hydration and infusion volume must be considered together.

Protect sodium bicarbonate powder from moisture and injection from freezing.