Intend using Valium regularly (3)
I believe the answer is:
aim
'intend' is the definition.
(aiming is a kind of intending)
'valium regularly' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'valium' are 'AIM'.
'using' is the link.
(Other definitions for aim that I've seen before include "Direct, intend" , "Point or direct, a weapon say" , "anticipated" , "Focus on target" , "Direct; intention" .)