Is Diamox (acetazolamide) used to treat shortness of breath (SOB) in the morning in a 74-year-old male (YOM) using Continuous Positive Airway Pressure (CPAP)?

Acetazolamide for Morning Shortness of Breath in a 74-Year-Old Male Using CPAP

Acetazolamide (Diamox) is not recommended as a first-line treatment for morning shortness of breath in a 74-year-old male using CPAP therapy for obstructive sleep apnea (OSA). Instead, optimization of existing CPAP therapy should be pursued first.

Assessment of Morning Shortness of Breath with CPAP

Morning shortness of breath in a patient using CPAP therapy could indicate:

• Inadequate CPAP pressure settings
• Residual sleep-disordered breathing despite CPAP
• Mask leaks or improper fit
• Development of central sleep apnea components
• Underlying cardiopulmonary conditions

Management Algorithm

Step 1: Optimize CPAP Therapy

• Review CPAP compliance data (hours of use, residual AHI, mask leak patterns)
• Consider increasing CPAP pressure in 1-2.5 cm H₂O increments if obstructive events persist 1
• Ensure proper mask fit and address any leaks
• Consider switching to BiPAP if pressures >15 cm H₂O are needed 1

Step 2: Consider Advanced PAP Modalities

• If central sleep apnea components are identified, consider:
  • BiPAP with backup rate (ST mode) 1
  • Adaptive Servo-Ventilation (ASV) if no heart failure with reduced ejection fraction 1

Step 3: Address Oxygenation

• Add supplemental oxygen if SpO₂ remains <90% for >5 minutes despite optimized PAP settings 1

Step 4: Consider Acetazolamide Only in Specific Scenarios

According to the European Respiratory Society guideline, carbonic anhydrase inhibitors like acetazolamide should only be used in the context of a randomized clinical trial, as there is no drug in this category with an approved label for OSA 2.

Role of Acetazolamide in Sleep-Disordered Breathing

Acetazolamide may be considered in very specific circumstances:

• For patients with complex sleep apnea (development of central apneas after CPAP initiation) who have failed other therapies 3
• For OSA at high altitude, where it has been shown to improve nocturnal oxygen saturation 2
• For patients with metabolic alkalosis and concurrent respiratory disorders 4, 5

The evidence supporting acetazolamide use in OSA is limited, with studies showing:

• Reduction in sleep apnea intensity (AHI) by up to 45% in unselected groups 2
• Improved oxygenation at altitude 2
• Potential blood pressure reduction 2

Important Caveats and Risks

• Acetazolamide has no FDA-approved indication for OSA 2
• Common side effects include paresthesia, vertigo, and unpleasant taste 2
• In elderly patients, there is a higher risk of metabolic acidosis and electrolyte disturbances
• Limited data exists for patients >60 years old 2
• May worsen respiratory function in some COPD patients 5

Conclusion for Clinical Practice

For a 74-year-old male experiencing morning shortness of breath while using CPAP, the primary approach should be to optimize the existing CPAP therapy rather than adding acetazolamide. A sleep medicine consultation with review of CPAP data and possibly a repeat sleep study would be more appropriate first steps.