Lecture on Salbutamol and Its Impact on Asthma Treatment

Introduction

• Salbutamol introduced around 1967.
• Significant reduction in asthma-related deaths:
  • 1965: 3 per 100,000 people (ages 15-44) died from asthma.
  • 1975: Reduced to just under 1 per 100,000.
  • Present: Less than 0.4 per 100,000.

Salbutamol: The First Inhaled Asthma Drug

• Functions by dilating bronchial tubes, increasing airflow.
• Works similarly to adrenaline, a neurotransmitter in the nervous system.

Understanding Adrenaline

• Adrenaline:

  • Contains nitrogen, oxygen, and a benzene ring.
  • Affects heart rate, blood vessel constriction, and bronchial dilation.

• Adrenaline and Noradrenaline:

  • Natural compounds with quick removal mechanisms from receptor sites.
  • Key removal mechanism: methylation of an oxygen atom.

Development of Salbutamol

• Innovators added an extra carbon between the benzene ring and oxygen.

  • Changed to a stronger benzylic OH bond.
  • Slower methylation, prolongs receptor presence.

• Salbutamol Mechanism:

  • Allows prolonged bronchial dilation.
  • Delivered as an aerosol, targeting active sites directly.
  • Minimizes systemic impact on heart and brain.

• Structural Modifications:

  • Methyl group modified to t-butyl group.
  • Increases specificity to beta-2 adrenoceptors.

Conclusion

• Salbutamol has saved millions of lives.
• Key factor in reducing asthma fatalities.
• Improved selectivity and bioavailability with structural changes.