Core book says that needlers are often used for delivering medicine. Under the medicines section, we learn that sedatives inflict 1d4 nonlethal damage, and are often injected via needler to subdue foes without killing them.
The problem is: a needler already deals 1d4 lethal piercing damage. How can it plausibly be used for healing or subdual? At 150 creds per dose of tier 1 drugs, that seems like a pretty narrow benefit.