Quaternary ammonium muscarinic receptor antagonists

Methoscopolamine bromide (Pamine) is a quaternary ammonium derivative of scopolamine and therefore lacks the central actions of scopolamine. It is less potent than atropine and is poorly absorbed however, its action is more prolonged, the usual oral dose (2.5 mg) acting for 6 to 8 h. Its use has been limited chiefly to gastrointestinal diseases. 

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Intranasal anticholinergics effectively reduce rhinorrhea. Ipratropium bromide, oxitropium bromide, tiotpropium bromide, and glycopyrrolate are quaternary structured ammonium muscarinic receptor antagonists, which are poorly absorbed into the systemic circulation. They reduce nasal secretions by influence on submucosal glands innervated by parasympathetic nerves (74). Intranasal anticholinergics are ineffective for control of allergic rhinitis symptoms other than rhinorrhea (74). 

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