ok to use a same AccessToken to call twitter api concurrently?

ok to use a same AccessToken to call twitter api concurrently?

I use twitter4j in a twitter client with OAuth. The same AccessToken is
used to make calls to the api concurrently:
to make calls to get/followers/ids and to get/friends/ids.
As I get quite a few 401 errors during these calls, I wondered if this
concurrent use of the same AccessToken was a possible source of the
problem?
Notes for clarification:
- the 401 code corresponds to an auth error in theory, but my auth is ok.
- the doc says the twitter4j Twitter object is fit for concurrency, but my
question is, even when the same AccessToken is passed to it?