<p>Ipratropium Bromide is a quaternary ammonium compound with anticholinergic properties. It appears to inhibit vagal reflexes by antagonising the action of acetylcholine (the transmitter agent released from the vagus nerve). Anticholinergics prevent the increase in intracellular concentration of cyclic guanosine monophosphate (cyclic GMP) caused by interaction of acetylcholine with the muscarinic receptor on bronchial smooth muscle.</p>