sodium bicarbonate
Brand: Neut (IV), generic
Prototype Drug
Drug Class: alkalinizing agent
Drug Family: electrolyte agent
Subclass: systemic antacid / buffer
Organ Systems: renalcardiovasculargastrointestinal
Mechanism of Action
Provides bicarbonate ions that buffer excess hydrogen ions in the blood and tissues, raising systemic pH; in the kidney, filtered bicarbonate is reabsorbed and urinary pH increases, alkalinizing urine and promoting excretion of weakly acidic drugs (salicylates, phenobarbital); as an antacid, neutralizes gastric hydrochloric acid.
systemic bicarbonate bufferurinary pHgastric acid (antacid)
Indications
- metabolic acidosis (severe, pH <7.1)
- hyperkalemia with cardiac toxicity (cardioprotection via membrane stabilization)
- urinary alkalinization (salicylate and phenobarbital toxicity)
- cardiac arrest (specific situations: TCA toxicity, hyperkalemia with dysrhythmia)
- chronic CKD-associated metabolic acidosis (oral)
- antacid
Contraindications
- metabolic or respiratory alkalosis
- hypocalcemia (tetany risk)
- hypokalemia
- hypochloremia with vomiting-associated alkalosis
Adverse Effects
Common
- metabolic alkalosis (with over-correction)
- hypernatremia
- hypokalemia
- fluid overload
Serious
- paradoxical CNS acidosis (IV bolus in respiratory failure)
- severe alkalemia causing tetany and dysrhythmia
- tissue necrosis from IV extravasation
- rebound hyperacidity (chronic antacid use)
Pharmacokinetics (ADME)
| Absorption | oral: absorbed from the GI tract and immediately enters the bicarbonate buffer system; IV: immediate effect |
| Distribution | distributes throughout extracellular fluid |
| Metabolism | metabolized to CO2 and water via carbonic anhydrase; CO2 exhaled |
| Excretion | renal excretion of filtered bicarbonate (when serum levels exceed reabsorptive threshold) |
| Half-life | N/A — bicarbonate is rapidly metabolized and excreted |
| Onset | IV: minutes; oral: 15-30 minutes |
| Peak | IV: within minutes |
| Duration | 1-3 hours for acute buffering |
| Protein Binding | N/A |
| Vd | extracellular fluid volume |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| lithium | alkalinization increases renal lithium excretion, lowering lithium levels — monitor lithium levels | moderate |
| weakly acidic drugs (aspirin, phenobarbital, methotrexate) | urinary alkalinization increases renal excretion by ion trapping | moderate |
| tetracyclines and fluoroquinolones | antacid effect reduces oral antibiotic absorption; separate by 2 hours | moderate |
| calcium-containing solutions | IV incompatibility — calcium carbonate precipitates on mixing | major |
Nursing Considerations
- For IV administration in cardiac arrest, administer as directed bolus (1 mEq/kg); avoid mixing sodium bicarbonate with calcium-containing solutions or medications such as epinephrine due to precipitation — flush IV line thoroughly between drugs.
- Monitor arterial blood gas and serum electrolytes (especially potassium and calcium) during IV sodium bicarbonate infusion; correct hypokalemia before or concurrently with bicarbonate to prevent worsening hypokalemia as pH normalizes.
- Over-alkalinization (pH >7.45) causes tetany (from ionized calcium decrease), dysrhythmias, and paradoxical CNS acidosis; reassess pH every 30-60 minutes and titrate dose to target pH 7.35-7.45.
- For oral use in CKD metabolic acidosis, target serum bicarbonate 22-26 mEq/L; monitor blood pressure and signs of fluid overload, as sodium content (~12 mEq sodium per 650 mg tablet) contributes to sodium load.
Clinical Pearls
- Sodium bicarbonate is the antidote for tricyclic antidepressant toxicity; it both alkalinizes the blood (reducing drug binding to cardiac sodium channels) and increases protein binding of TCAs, reducing free drug concentration available for cardiac toxicity.
- The first-line use of IV sodium bicarbonate for routine metabolic acidosis in septic shock is no longer recommended in current guidelines; its use is reserved for severe acidemia (pH <7.1) when benefits of improved hemodynamics outweigh sodium and fluid loading risks.
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.
Alkalinizing Agent Antacid Cardiac Arrest (specific Situations: TCA Toxicity, Hyperkalemia With Dysrhythmia) Chronic CKD-associated Metabolic Acidosis (oral) Hyperkalemia With Cardiac Toxicity (cardioprotection Via Membrane Stabilization) Metabolic Acidosis (severe, PH <7.1) Urinary Alkalinization (salicylate And Phenobarbital Toxicity)