CHRM2 and obstructive sleep apnea syndrome: New research indicates that optimal combination pharmacotherapy strategies for treating OSA should involve broad antimuscarinic M-subtype receptor selectivity or possibly M2 muscarinic receptor selectivity with high blood-brain barrier permeability [112]. Pharmacological therapies for OSA, while approved for symptom management, lack robust evidence for long-term effectiveness in controlling the disorder itself, and further research is needed to confirm their role in treatment.