Immediate cessation(cold turkey) or overdose of Baclofen is reported to cause convulsive(seizure) episodes,
psychological crashing and uncontrollable muscle spasms.
In some patients diagnosed with Parkinson's Disease, hallucination, anxiety, nausea and immediate confusion have been reported after administration of l-dopamine and baclofen.
In terms of safety profile, I would suggest that there is always the possibility of addiction, however potential benefits outweigh the risk of adverse side effects in most patients.
Yours,
Tez