SODIUM BICARBONATE NA(HCO₃)
(sod'i-um bi-car'bon-ate)
Sodium Bicarbonate
Classifications: gastrointestinal agent; antacid; fluid and electrolyte balance agent
Pregnancy Category: C

Availability

325 mg, 520 mg, 650 mg tablets; 4.2%, 5%, 7.5%, 8.4% injection

Actions

Short-acting, potent systemic antacid. Rapidly neutralizes gastric acid to form sodium chloride, carbon dioxide, and water. After absorption of sodium bicarbonate, plasma alkali reserve is increased and excess sodium and bicarbonate ions are excreted in urine, thus rendering urine less acid. Not suitable for treatment of peptic ulcer because it is short-acting, high in sodium, and may cause gastric distention, systemic alkalosis, and possibly acid-rebound.

Therapeutic Effects

Short-acting, potent systemic antacid; rapidly neutralizes gastric acid or systemic acidosis.

Uses

Systemic alkalinizer to correct metabolic acidosis (as occurs in diabetes mellitus, shock, cardiac arrest, or vascular collapse), to minimize uric acid crystallization associated with uricosuric agents, to increase the solubility of sulfonamides, and to enhance renal excretion of barbiturate and salicylate overdosage. Commonly used as home remedy for relief of occasional heartburn, indigestion, or sour stomach. Used topically as paste, bath, or soak to relieve itching and minor skin irritations such as sunburn, insect bites, prickly heat, poison ivy, sumac, or oak. Sterile solutions are used to buffer acidic parenteral solutions to prevent acidosis. Also as a buffering agent in many commercial products (e.g., mouthwashes, douches, enemas, ophthalmic solutions).

Contraindications

Prolonged therapy with sodium bicarbonate; patients losing chloride (as from vomiting, GI suction, diuresis); heart disease, hypertension; renal insufficiency; peptic ulcer; pregnancy (category C).

Cautious Use

Edema, sodium-retaining disorders; lactation; older adult patients.

Route & Dosage

Antacid
Adult: PO 0.3–2 g 1–4 times/d or ½ tsp of powder in glass of water

Urinary Alkalinizer
Adult: PO 4 g initially, then 1–2 g q4h
Child: PO 84–840 mg/kg/d in divided doses

Cardiac Arrest
Adult: IV 1 mEq/kg of a 7.5% or 8.4% solution initially, then 0.5 mEq/kg q10 min depending on arterial blood gas determinations (8.4% solutions contain 50 mEq/50 mL), give over 1–2 min
Child: IV 0.5–1 mEq/kg of a 4.2% solution q10 min depending on arterial blood gas determinations, give over 1–2 min

Metabolic Acidosis
Adult: IV 2–5 mEq/kg by IV infusion over 4–8 h
Infant: IV 2–3 mEq/kg/d of a 4.2% solution over 4–8 h

Administration

Oral

Do not add oral preparation to calcium-containing solutions.

Topical

Use manufacturer's directions: Bath or soak, ½ cup or more into tub of warm water; Footsoak, 4 tbsp/L(qt) warm water; soak 5–10 min; Paste, 3 parts sodium bicarbonate to 1 part water
Note: Solutions in water slowly decompose, decomposition is accelerated by agitating or warming the solution.

Intravenous

PREPARE: IV Infusion: May give 4.2% (0.5 mEq/mL) and 5% (0.595 mEq/mL) NaHCO₃ solutions undiluted. Dilute 7.5% (0.892 mEq/mL) and 8.4% (1 mEq/mL) solutions with compatible IV solutions. Dilute to at least 4.2% for infants and children.

ADMINISTER: IV Infusion: Give a bolus dose only in emergency situations. Usually, the rate is 2–5 mEq/kg over 4–8 h; do not exceed 50 mEq/h. Stop infusion immediately if extravasation occurs. Severe tissue damage has followed tissue infiltration.

INCOMPATIBILITIES Solution/additive: Alcohol 5%, lactated Ringer's, amoxicillin, ascorbic acid, bupivacaine, carboplatin, carmustine, cisplatin, codeine, corticotropin, dobutamine, dopamine, epinephrine, etidocaine, glycopyrrolate, hydromorphone, imipenem-cilastatin, insulin, isoproterenol, labetalol, levorphanol, lidocaine, magnesium sulfate, meperidine, mepivacaine, meropenem, methadone, metoclopramide, morphine, norepinephrine, oxytetracycline, pentazocine, pentobarbital, phenobarbital, procaine, secobarbital, streptomycin, succinylcholine, tetracycline, thiopental, vancomycin, vitamin B complex with C. Y-site: Allopurinol, amiodarone, amphotericin B cholesteryl complex, calcium chloride, diltiazem, doxorubicin liposome, idarubicin, imipenem/cilastatin, inamrinone, leucovorin, midazolam, nalbuphine, ondansetron, oxacillin, sargramostim, verapamil, vincristine, vindesine, vinorelbine.

Store in airtight containers.
Note expiration date.

Adverse Effects (1%)

GI: Belching, gastric distention, flatulence. Metabolic: Metabolic alkalosis; electrolyte imbalance: sodium overload (pulmonary edema), hypocalcemia (tetany), hypokalemia, milk-alkali syndrome, dehydration. Other: Rapid IV in neonates (Hypernatremia, reduction in CSF pressure, intracranial hemorrhage). Skin: Severe tissue damage following extravasation of IV solution. Urogenital: Renal calculi or crystals, impaired kidney function.

Diagnostic Test Interference

Small increase in blood lactate levels (following IV infusion of sodium bicarbonate); false-positive urinary protein determinations (using ames reagent, sulfacetic acid, heat and acetic acid or nitric acid ring method); elevated urinary urobilinogen levels (urobilinogen excretion increases in alkaline urine).

Interactions

Drug: May decrease absorption of ketoconazole; may decrease elimination of dextroamphetamine, ephedrine, pseudoephedrine, quinidine; may increase elimination of chlorpropamide, lithium, salicylates, tetracyclines.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Onset: 15 min. Duration: 1–2 h. Elimination: Excreted in urine within 3–4 h.

Nursing Implications

Assessment & Drug Effects

Be aware that long-term use of oral preparation with milk or calcium can cause milk-alkali syndrome: Anorexia, nausea, vomiting, headache, mental confusion, hypercalcemia, hypophosphatemia, soft tissue calcification, renal and ureteral calculi, renal insufficiency, metabolic alkalosis.
Lab tests: Urinary alkalinization: Monitor urinary pH as a guide to dosage (pH testing with nitrazine paper may be done at intervals throughout the day and dosage adjustments made accordingly).
Lab tests: Metabolic acidosis: Monitor patient closely by observations of clinical condition; measurements of acid-base status (blood pH, Po₂, Pco₂, HCO₃ ^–, and other electrolytes, are usually made several times daily during acute period). Observe for signs of alkalosis (over treatment) (see Appendix F).
Observe for and report S&S of improvement or reversal of metabolic acidosis (see Appendix F).

Patient & Family Education

Do not use sodium bicarbonate as antacid. A nonabsorbable OTC alternative for repeated use is safer.
Do not take antacids longer than 2 wk except under advice and supervision of a physician. Self-medication with routine doses of sodium bicarbonate or soda mints may cause sodium retention and alkalosis, especially when kidney function is impaired.
Be aware that commonly used OTC antacid products contain sodium bicarbonate: Alka-Seltzer, Bromo-Seltzer, Gaviscon.
Do not breast feed while taking this drug without consulting physician.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug