What is the dose of Asthalin (salbutamol) for hyperkalemia?

Asthalin (Salbutamol) Dosage for Hyperkalemia

The recommended dose of nebulized salbutamol (Asthalin) for hyperkalemia is 20 mg in 4 mL, administered over 15 minutes. 1

Mechanism of Action

• Salbutamol, a beta-2 adrenergic agonist, promotes potassium shift into cells by stimulating the Na+/K+-ATPase pump, temporarily reducing serum potassium levels 2
• The hypokalemic effect begins within 15-30 minutes after administration and lasts for 2-4 hours 2
• Salbutamol does not eliminate potassium from the body but redistributes it intracellularly 1

Clinical Application in Hyperkalemia Management

Indications

• Salbutamol is indicated as part of acute hyperkalemia management, particularly when rapid reduction of serum potassium is needed 1, 2
• It can be used alongside other temporizing measures like calcium administration and insulin/glucose 2

Administration

• Nebulized salbutamol at 20 mg in 4 mL is the standard dose for adults with hyperkalemia 1
• Alternative administration routes include:
  • Intravenous infusion: 0.5 mg (though this may cause more pronounced cardiovascular side effects) 3
  • For pediatric patients: 5 μg/kg over 15 minutes has been shown to be effective 4

Expected Response

• Nebulized salbutamol can reduce serum potassium by approximately 0.85-0.95 mEq/L 5, 3
• Maximum effect occurs within 30 minutes for IV administration and 90 minutes for nebulization 3
• The hypokalemic effect persists for at least 3 hours 5, 6

Comprehensive Hyperkalemia Management Algorithm

Step 1: Cardiac Membrane Stabilization (Immediate Effect)

• Administer IV calcium: calcium gluconate 10% (15-30 mL) or calcium chloride 10% (5-10 mL) over 2-5 minutes 2
• Effects begin within 1-3 minutes but are temporary (30-60 minutes) 2

Step 2: Shift Potassium into Cells (Effect within 15-60 minutes)

• Administer nebulized salbutamol: 20 mg in 4 mL over 15 minutes 1
• Administer insulin with glucose: 10 units regular insulin IV with 25g glucose (50 mL of D50W) over 15-30 minutes 2
• Consider sodium bicarbonate (50 mEq IV over 5 minutes) if metabolic acidosis is present 7

Step 3: Eliminate Potassium from Body (Longer-term Effect)

• Loop diuretics (e.g., furosemide 40-80 mg IV) if adequate renal function is present 2
• Consider potassium binders 1
• Hemodialysis for severe or resistant hyperkalemia, especially in patients with renal failure 2

Important Clinical Considerations

• Temporary measures like salbutamol and insulin/glucose provide only transient effects, and rebound hyperkalemia can occur after 2-4 hours 2
• Monitoring of potassium levels should be done every 2-4 hours after initial administration 7
• Cardiovascular side effects (tachycardia) are more common with IV administration than with nebulization 3
• Nebulized salbutamol should be preferred over IV administration in patients with coronary artery disease 5, 3
• Approximately 25-33% of patients with chronic renal failure may be resistant to salbutamol treatment 5, 3

Patient Selection and Contraindications

• Salbutamol is particularly useful in patients requiring rapid potassium reduction but who may not tolerate the glucose load associated with insulin therapy 6
• Use with caution in patients with tachyarrhythmias, coronary artery disease, or hyperthyroidism 2
• Consider alternative treatments in patients who have previously demonstrated resistance to beta-agonist therapy 5