The use of CCR3 antagonists of the formula I
or a pharmaceutically acceptable salt thereof for the treatment of asthma is disclosed, as well as novel compounds of the formula II,
pharmaceutical compositions comprising them, and their use in the treatment of asthma, wherein R, R
a
, X, X
a
, R
1
, R
2
, R
2a
, R
14
, R
14a
, R
16
and n are as defined in the specification.