Sodium Bicarbonate

Class: Alkalinizing Agents
CAS Number: 144-55-8
Brands: Baking Soda, Neut, Soda Mint

Introduction

Alkalinizing agent.^{a 103}

Uses for Sodium Bicarbonate

Acidosis

Treatment of metabolic acidosis associated with many conditions including severe renal disease (e.g., renal tubular acidosis), uncontrolled diabetes (ketoacidosis), extracorporeal circulation of the blood, cardiac arrest, circulatory insufficiency caused by shock or severe dehydration, ureterosigmoidostomy, lactic acidosis, alcoholic ketoacidosis, use of carbonic anhydrase inhibitors, and ammonium chloride administration.^a

Generally considered the alkalinizing agent of choice for oral or parenteral therapy.^a

Diabetic Ketoacidosis

Specific role of sodium bicarbonate therapy in the treatment of diabetic ketoacidosis not established.^a Administration is generally reserved for the treatment of severe acidosis (e.g., arterial pH less than 7–7.15 or serum bicarbonate concentration of 8 mEq/L or less) because of the potential risks of sodium bicarbonate therapy in the treatment of this disorder.^b

Cardiopulmonary Resuscitation

The Guidelines on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care state that IV sodium bicarbonate is not recommended for routine use in ACLS.^{101 103} May be useful in some resuscitation situations (e.g., preexisting metabolic acidosis, hyperkalemia, tricyclic antidepressant overdosage, sodium-channel blocking agent toxicity, prolonged cardiac arrest).¹⁰³

Alkalinization of Urine

Treatment of hemolytic reactions requiring alkalinization of the urine to diminish the nephrotoxic effects of blood pigments; also to increase urinary pH in order to increase the solubility of certain weak acids (e.g., cystine, sulfonamides, uric acid).^a

Sodium Bicarbonate Dosage and Administration

General

• Dosage is determined by severity of the acidosis, appropriate laboratory determinations, and the patient’s age, weight, and clinical condition.^a Frequent laboratory determinations and clinical evaluation of the patient are essential during therapy, especially during prolonged therapy, to monitor changes in fluid and electrolyte and acid-base balance.^a

• Full correction of bicarbonate deficit should not be attempted during the first 24 hours of sodium bicarbonate therapy, since this may result in precipitation of metabolic alkalosis because of delayed physiologic compensatory mechanisms.^a

• Fluid and electrolyte balance of the patient must be carefully monitored during therapy with the drug because of the sodium content of sodium bicarbonate.^a

Administration

Administer orally, by direct IV injection or infusion.^a

May be administered by intraosseous injection† in pediatric patients without reliable/immediate IV access undergoing cardiopulmonary resuscitation.^{102 103}

Also administered by subcutaneous injection if diluted to isotonicity (1.5% sodium bicarbonate solution); avoid extravasation of hypertonic sodium bicarbonate injections.^a

Oral Administration

Administered orally in the treatment of mild to moderately severe acidosis, in conditions (e.g., chronic renal failure) requiring prolonged therapy with an alkalinizing agent, and in conditions in which IV administration of the drug is not necessary (e.g., alkalinization of the urine).

IV Administration

For solution and drug compatibility information, see Compatibility under Stability.

Rate of Administration

Neonates and children <2 years of age: Administer hypertonic sodium bicarbonate injections by slow IV infusion of a 4.2% solution (up to 8 mEq/kg daily).^a

Dosage

Each 84 mg or 1 g of sodium bicarbonate contains 1 or about 12 mEq, respectively, each of sodium and bicarbonate ions.^a

Pediatric Patients

Metabolic Acidosis

IV

Older children: 2–5 mEq/kg as an infusion over 4–8 hours in less urgent forms of metabolic acidosis.^a Subsequent doses should be determined by the response of the patient and appropriate laboratory determinations.^a

Plan sodium bicarbonate therapy in a stepwise manner, since the degree of response following a given dose is not always predictable.^a Reduce dose and frequency of administration after severe symptoms have improved.^a

Cardiopulmonary Resuscitation

IV

Infants and children: Initially, 1 mEq/kg (1 mL/kg of an 8.4% sodium bicarbonate solution).¹⁰³

Drug-induced cardiovascular emergencies (tricyclic antidepressant or other sodium-channel blocking agent toxicity): 1–2 mEq/kg by direct IV injection until the arterial pH >7.45, then infuse 150 mEq/L in 5% dextrose injection to maintain alkalosis; in severe intoxication, the pH has been increased to 7.5–7.55.¹⁰³

Ventricular arrhythmias associated with cocaine toxicity: 1–2 mEq/kg.¹⁰³

Intraosseous†

Infants and children: Initially, 1 mEq/kg (1 mL/kg of an 8.4% sodium bicarbonate solution).¹⁰³

Alkalinization of Urine

Oral

1–10 mEq (84–840 mg) per kg daily, adjusted according to response.^a

Adults

Metabolic Acidosis

IV

Initially, administer no more than 33–50% of the calculated bicarbonate requirements when initial, rapid administration of the drug is considered necessary.^a Consult specialized references on fluid and electrolyte and acid-base balance for specific recommendations.^a

2–5 mEq/kg dose as an infusion over 4–8 hours in less urgent forms of metabolic acidosis.^a Subsequent doses should be determined by the response of the patient and appropriate laboratory determinations.^a Therapy should be planned in a stepwise manner, since the degree of response following a given dose is not always predictable.^a Generally, the dose and frequency of administration should be reduced after severe symptoms have improved.^a

Diabetic Ketoacidosis

IV

Partially correct acidosis, generally to an arterial pH of about 7.2, in order to avoid rebound alkalosis.^a

Cardiopulmonary Resuscitation

IV

Initially, 1 mEq/kg.¹⁰³

Drug-induced cardiovascular emergencies (tricyclic antidepressant or sodium-channel blocking agent [e.g., procainamide, flecainide] toxicity): 1–2 mEq/kg by repeated direct IV injections to maintain an arterial pH of 7.45–7.55.¹⁰³ Maintenance infusion of 150 mEq/L plus 30 mEq of potassium chloride per liter in 5% dextrose injection recommended.¹⁰³ For acute decompensation, may administer sodium bicarbonate direct IV injections without determining serum pH, if QRS interval >100 msec or hypotension develops.¹⁰³

Acidosis Associated with Chronic Renal Failure

Oral

Initially, 20–36 mEq daily, given in divided doses when plasma bicarbonate concentration is less than 15 mEq/L.^a Titrate dosage to provide a plasma bicarbonate concentration of about 18–20 mEq/L.^a To relieve symptoms and prevent or stabilize renal failure and osteomalacia in patients with renal tubular acidosis, higher dosages of sodium bicarbonate are necessary.^a

Distal (type 1) renal tubular acidosis: Initially, 0.5–2 mEq/kg daily, given in 4 or 5 divided doses.^a Titrate dosage until hypercalciuria and acidosis are controlled, and according to the response and tolerance of the patient.^a Alternatively, 48–72 mEq (about 4–6 g) daily.^a

Proximal (type 2) renal tubular acidosis: 4–10 mEq/kg daily, given in divided doses.^a

Alkalinization of Urine

Oral

Initially, 48 mEq (4 g), followed by 12–24 mEq (1–2 g) every 4 hours.^a Dosages of 30–48 mEq (2.5–4 g) every 4 hours, up to 192 mEq (16 g) daily, may be required in some patients.^a Titrate dosage to maintain the desired urinary pH.^a

Cautions for Sodium Bicarbonate

Contraindications

• Metabolic or respiratory alkalosis.^a

• Hypocalcemia in which alkalosis may induce tetany.^a

• Excessive chloride loss from vomiting or continuous GI suctioning.^a

• Risk of developing diuretic-induced hypochloremic alkalosis.^a

• Oral administration as an antidote in the treatment of acute ingestion of strong mineral acids, since formation of carbon dioxide gas during neutralization may cause gastric distention and possible rupture.^a

Warnings/Precautions

Warnings

CHF

Use with extreme caution in patients with CHF.^a

Fluid and/or Solute Overload

Possible fluid and/or solute overload following IV administration resulting in dilution of serum electrolytes, overhydration, congestive conditions, or pulmonary edema.^a Risk of dilutional conditions is inversely proportional to the electrolyte concentration administered.^a Risk of solute overload and resultant congestive conditions with peripheral and/or pulmonary edema is directly proportional to the electrolyte concentration administered.^a

Major Toxicities

Electrolyte Disturbances

Possible hypokalemia and decreased ionized serum calcium concentration with excessive IV administration.^{a 103} Potassium depletion may predispose to metabolic alkalosis and coexistent hypocalcemia may result in tetany and carpopedal spasm as the plasma pH increases.^a Correct electrolyte disturbances prior to or concomitantly with administration of sodium bicarbonate therapy to minimize the risks of preexisting hypokalemia and/or hypocalcemia.^a

General Precautions

Dosing Considerations

Generally, the goal of alkalinizing therapy is to correct the acid-base disturbance while avoiding overdosage and resultant metabolic alkalosis.^a Repeated fractional doses of sodium bicarbonate and periodic laboratory determinations of the patient’s acid-base status are recommended to minimize the risk of overdosage.^{a 103}

Extravasation

Chemical cellulitis with inadvertent extravasation of hypertonic solutions, subsequently resulting in tissue necrosis, ulceration, and/or sloughing at the site of injection.^a Treat extravasation by elevating the affected area, applying warm compresses to the site, and locally injecting lidocaine or hyaluronidase.^a

Specific Populations

Pregnancy

Category C.^b

Pediatric Use

Neonates and children < 2 years of age: Rapid injection (10 mL/minute) of hypertonic sodium bicarbonate solutions may produce hypernatremia, decreased CSF pressure, and possible intracranial hemorrhage.^a

Renal Impairment

Use with extreme caution in patients with renal insufficiency, especially those with severe insufficiency such as oliguria or anuria.^a

When given in large doses or to patients with renal insufficiency, may cause metabolic alkalosis.^{a 103} Metabolic alkalosis may be accompanied by hyperirritability or tetany; tetany is particularly likely to occur in patients with hypocalcemia, as may occur in uremia, since bicarbonate-induced increase in pH increases the binding of calcium to albumin.^a Metabolic alkalosis may impair the release of oxygen from peripheral tissues, possibly resulting in lactic acidosis.^{a 103}

Common Adverse Effects

Gastric distention and flatulence with oral administration.^a

Interactions for Sodium Bicarbonate

Specific Drugs

Stability

Storage

Oral

Tablets

Tight containers at 15–30°C.^a

Parenteral

Injection

15–30°C.^a Avoid freezing and extreme heat.^b

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

Solution Compatibility^HID

Drug Compatibility

Actions

• Dissociates to provide bicarbonate ion; bicarbonate is the conjugate base component of the principal extracellular buffer in the body, the bicarbonate:carbonic acid buffer.^a Changes in the concentration of either component of the buffer can cause a decrease or increase in pH.^a

• Administration of sodium bicarbonate, by decreasing pH, can cause a redistribution of potassium ions into cells in patients with acidosis.^a

• Provides bicarbonate, which is readily excreted in urine; administration of the drug will increase urinary pH in patients with normal renal function.^a Alkalinizing the urine can increase the solubility of certain weak acids (e.g., cystine, uric acid) and can increase the ionization and urinary excretion of lipid-soluble organic acids (e.g., phenobarbital, salicylates) that are reabsorbed in the kidney via diffusion of the un-ionized species.^a

• Potent antacid action; each gram of sodium bicarbonate has an in vitro neutralizing capacity of about 12 mEq of acid.^a

Advice to Patients

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs as well as any concomitant illnesses.^b

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.^b

• Importance of informing patients of other important precautionary information. (See Cautions.)^b

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name