Tridihexethyl
Tridihexethyl (which is commonly used as its chloride salt, tridihexethyl chloride)  is an anticholinergic, antimuscarinic and antispasmodic drug.  It may be used, usually in combination with other drugs, to treat acquired nystagmus or peptic ulcer disease. Many patients discontinue the drug because of unwanted side effects.

It is also known as Pathilon or Propethonum.

References 

Muscarinic antagonists
Quaternary ammonium compounds
Tertiary alcohols