Below is some of what I discovered here: http://home.pacbell.net/drcns/baclofen.htmBaclofen is a medication that helps with muscle spasms, cramps and abnormally increased tone. It works on GABA receptors in the spinal cord and in the cerebellum. Baclofen is similar to benzodiazepines such as Valium® or Klonopin® in terms of effectiveness, but baclofen works mostly in the spinal cord and not as much in the brain. Since baclofen does not work as much in the brain, there tend to be fewer side effects compared with the benzodiazepines.
In the spinal cord, baclofen helps block some of the signals that go to the muscles, making the muscles contract less. This helps relieve cramps, shakes and spasms. If you use a lot of baclofen, the muscles can seem weak, because the signals are blocked too much. Also, if you too much baclofen, you may have a hard time controlling urine because the signals to the bladder muscles also can be blocked. If such problems occur, the dose is too high. You should decrease the dose and call the office for instructions.
Baclofen should be used carefully in cases of liver or kidney disease. Common side effects include sleepiness, especially when the medication is first started, lowered blood pressure and less likely, dizziness or confusion. Sometimes baclofen causes nausea or stomach upset.
The medication is titrated gradually as the patient tolerates to an effective dose. Every few days, after any initial sleepiness or other side effects go away, the dose can be increased to the next level. Go to the next level only if needed and only if you have no problems on the current level. Baclofen should NEVER be stopped suddenly.