What are the management steps for excess administration of inhalers, such as salbutamol (short-acting beta-2 agonist) or fluticasone-salmeterol (combination inhaler)?

Management of Excess Administration of Inhalers

In cases of excess administration of inhalers such as salbutamol or fluticasone-salmeterol, immediate assessment of respiratory status and vital signs is critical, followed by supportive care and monitoring for specific medication toxicity. 1

Initial Assessment

• Assess for signs of impending respiratory failure:

  • Inability to speak
  • Altered mental status
  • Intercostal retraction
  • Worsening fatigue
  • PaCO2 of 42 mm Hg or greater 1

• Vital signs monitoring:

  • Heart rate (tachycardia with beta-agonists)
  • Blood pressure
  • Respiratory rate
  • Oxygen saturation

Management Based on Inhaler Type

Short-Acting Beta-2 Agonists (SABA) Overdose (e.g., Salbutamol)

1. Monitor for common toxicity symptoms:

   • Tachycardia/palpitations
   • Tremor
   • Headache
   • Hypokalemia
   • Hyperglycemia
   • QT interval prolongation 2

2. Treatment approach:

   • Provide oxygen to maintain SaO2 >90% (>95% in pregnant women and patients with heart disease) 2
   • Monitor serum potassium levels and replace if necessary
   • Consider IV fluids for hydration
   • For severe tachycardia, consider cardioselective beta-blockers only in consultation with specialist and with extreme caution 1

Combination Inhaler Overdose (e.g., Fluticasone-Salmeterol)

1. Monitor for combined toxicity:

   • All SABA toxicity symptoms (from salmeterol component)
   • Potential systemic corticosteroid effects with very high doses:
     • Hyperglycemia
     • Mood alterations
     • Increased appetite 2

2. Treatment approach:

   • Same supportive care as for SABA overdose
   • Monitor blood glucose levels
   • Note: Systemic effects from inhaled corticosteroids are rare with short-term overdose 3

Monitoring and Follow-up

• For severe cases:

  • Continuous cardiac monitoring
  • Repeat arterial blood gas measurements if initially abnormal or if clinical deterioration occurs 1
  • Consider hospital admission for patients with significant symptoms or abnormal vital signs

• For mild to moderate cases:

  • Observation for 4-6 hours to ensure symptoms are resolving
  • Discharge when heart rate, respiratory rate, and symptoms have normalized 1

Patient Education Before Discharge

• Review proper inhaler technique to prevent future overdose
• Provide clear written instructions on correct dosing
• Ensure patient understands maximum daily doses:
  • Salbutamol: Maximum 8 puffs in 24 hours for adults (less for children) 1
  • Fluticasone-salmeterol: Maximum twice daily dosing 4

Special Considerations

• Children: Lower threshold for admission and monitoring due to higher sensitivity to beta-agonist effects

• Patients with cardiac history: Higher risk of adverse effects from beta-agonist overdose; require closer monitoring

• Patients with known electrolyte disorders: Monitor electrolytes more frequently

• Common pitfall: Failing to recognize that symptoms may be due to the underlying respiratory condition rather than medication overdose. Assess baseline respiratory status carefully.

• Caution: Sedatives of any kind are contraindicated in patients with respiratory conditions, as they may worsen respiratory depression 2

Remember that most cases of inhaler overdose can be managed with supportive care and monitoring, with symptoms typically resolving within 4-6 hours as the medications are metabolized.