<unk>  reduces the stimulation of smooth muscle contraction and the production of respiratory secretions. These are normally stimulated by the parasympathetic nervous system, via the neurotransmitter acetylcholine. As an antimuscarinic,<unk>  binds to muscarinic acetylcholine receptors, blocking their effect. It is a quaternary ammonium compound and a semisynthetic derivative of<unk>  hydrobromide (scopolamine). The attachment of the<unk>  moiety effectively prevents the movement of this drug across the blood–brain barrier, effectively minimising undesirable central nervous system side effects associated with scopolamine/hyoscine.
Hyoscine butylbromide
Halofantrine
Terbutaline
Bromethalin
Acetomepregenol
Oxymetazoline
Levomepromazine
Pilocarpine