Baclofen is not a medication for vertigo. It's a medication for spasticity. Spasticity is probably best described as muscle stiffness. Like muscle spasms in the leg (i.e. charley horses) and The Hug, which is a sensation like someone is hugging you around your ribs. Usually it's not a very comforting "hug".

Baclofen relaxes the muscles and sometimes helps with the pain that spasticity can trigger.

One of it's listed side effects is actually dizziness. I know when I take too much that it can make my head spin a bit more and I'll feel more wobbly.

If you're having vertigo, you can ask your neuro/doctor for an anti-emetic, like Meclizine or Dramamine.