Is there evidence for using Buspirone (an anxiolytic medication) to treat central sleep apnea?

Treatment of Central Sleep Apnea with Buspirone

There is limited evidence supporting the use of buspirone for central sleep apnea, with only small studies showing modest effects, and it is not recommended as a first-line treatment option for central sleep apnea according to current guidelines.

Evidence for Buspirone in Central Sleep Apnea

Current Guidelines and Evidence Quality

The European Respiratory Journal guidelines do not recommend drug therapy as treatment for sleep apnea (most drugs receiving grade C recommendation, with some specific medications like mirtazapine and protriptyline receiving grade B negative recommendations) 1. The guidelines specifically mention buspirone in their search strategy but do not provide specific recommendations for its use in central sleep apnea.

Specific Evidence for Buspirone

Recent research provides some limited evidence regarding buspirone for specific types of central sleep apnea:

1. Heart Failure-Associated CSA: A small crossover study of buspirone versus placebo for CSA associated with heart failure (n=16) showed modest improvements:

   • Median reduction in central apnea-hypopnea index (cAHI) of 5.00 events/hour
   • Median reduction in overall AHI of 6.00 events/hour
   • No significant change in daytime sleepiness 2

2. Spinal Cord Injury-Associated CSA: A 2020 study in patients with chronic spinal cord injury (n=8) found that buspirone:

   • Significantly widened CO2 reserve compared to both trazodone and placebo (-3.6 ± 0.9 mmHg vs -1.8 ± 1.5 mmHg for placebo)
   • Decreased controller gain (chemosensitivity) compared to placebo
   • Did not significantly improve standard sleep apnea indices (AHI, central apnea index, oxygen desaturation index) 3

Treatment Algorithm for Central Sleep Apnea

First-Line Approaches (Based on CSA Type)

1. Heart Failure-Associated CSA:

   • Optimize heart failure treatment according to cardiology guidelines 4
   • Consider CPAP (reduces AHI in approximately 45% of patients) 4
   • Consider adaptive servo-ventilation (ASV) if no contraindications exist (avoid in heart failure with reduced ejection fraction ≤45%) 4

2. Altitude-Related CSA:

   • Acclimatization and descent to lower altitude when possible 4
   • Consider supplemental oxygen therapy 4

3. Traumatic Brain/Spinal Cord Injury-Related CSA (TECSA):

   • Address underlying spinal cord injury and monitor for resolution 4
   • Consider waiting 3 months on CPAP therapy as TECSA often resolves spontaneously 4

Second-Line Approaches

For cases where first-line treatments are ineffective or contraindicated:

1. Pharmacologic Options:

   • Acetazolamide may be considered (very low certainty evidence) 5, 2
   • Buspirone could be considered for specific cases like spinal cord injury-related CSA 3
   • Theophylline may be considered for heart failure-associated CSA (very low certainty evidence) 2

2. Advanced Interventions:

   • Phrenic nerve stimulation for persistent, severe CSA when other treatments have failed 4

Practical Considerations for Buspirone Use

If considering buspirone despite limited evidence:

• Dosing: Studies used 7.5-15 mg twice daily 3
• Duration: Most studies were short-term (3 days to 1 week) 2
• Safety: Adverse events were reported as rare and mild 2
• Monitoring: Regular assessment of treatment response and side effects is essential

Limitations and Caveats

• The overall quality of evidence for pharmacological treatments in CSA is low 2
• Most studies on buspirone have small sample sizes and short follow-up periods
• Long-term efficacy and safety data are lacking
• Buspirone's effects appear to be modest and may vary based on the underlying cause of CSA
• Current guidelines do not specifically recommend buspirone for CSA treatment 1, 4

In clinical practice, addressing the underlying cause of CSA and using established treatments like positive airway pressure therapy should be prioritized before considering pharmacological options like buspirone.