Muscarinic antagonists in early stage clinical development for the treatment of asthma.

Parasympathetic neurons utilize the neurotransmitter acetylcholine to modulate and constrict airway smooth muscles at the muscarinic acetylcholine receptor. Inhaled agents that antagonize the muscarinic (M) acetylcholine receptor, particularly airway M3 receptors, have increasing data supporting use in persistent asthma. Areas covered: Use of inhaled long-acting muscarinic antagonists (LAMA) in asthma is explored. The LAMA tiotropium is approved for maintenance in symptomatic asthma patients despite the use of inhaled corticosteroids (ICS), leukotriene receptor antagonists (LTRA) and/or long-acting beta