A NK₁ antagonist having the formula (I), ##STR1##

wherein Ar¹ and Ar² are optionally substituted phenyl or heteroaryl, X¹ is an ether, thio or imino linkage, R⁴ and R⁵ are not both H or alkyl, and the remaining variables are as defined in the specification, useful for treating a number of disorders, including emesis, depression, anxiety and cough. Pharmaceutical compositions. Methods of treatment and combinations with other agents are also disclosed.