Final answer:
Inhaled anticholinergic drugs such as atropine work by blocking muscarinic acetylcholine receptors, reducing parasympathetic stimulation to the lungs, and alleviating symptoms like bronchial secretions. Some of these drugs can more effectively cross the blood-brain barrier, which is beneficial in cases of nerve agent poisoning. Treatment typically continues until bronchial secretions are cleared.
Step-by-step explanation:
Inhaled anticholinergic drugs are a type of medication primarily used to treat conditions affecting the respiratory system by blocking the action of the neurotransmitter acetylcholine. Drugs such as atropine and scopolamine act as antagonists to muscarinic acetylcholine receptors. When anticholinergic drugs are administered, they prevent acetylcholine from binding to these receptors, which normally stimulate activities such as bronchial secretion and constriction of airway muscles. Therefore, they lead to a reduced parasympathetic stimulation of the lungs, helping clear bronchial secretions and relax the airway muscles — effects that are crucial for managing the symptoms of nerve agent poisoning together with the use of oximes.
Some synthetic anticholinergics like biperiden can cross the blood-brain barrier more effectively than atropine, making them more suitable for counteracting the central symptoms of nerve agent poisoning. As for the use of anticholinergics in treating conditions like motion sickness, the transdermal scopolamine patch is noteworthy for controlling the release of the drug and minimizing potential dangers associated with higher doses.
The endpoint for administrating medication like atropine is typically determined by the clearing of bronchial secretions, indicating reduced activity of acetylcholine in the parasympathetic nervous system affecting the lungs. When discussing the treatment of poisoning, it is important to note that while anticholinergics manage symptoms, drugs such as oximes are used to directly counteract the poison's effects.