Baclofen is a medication commonly used to decrease spasticity related to multiple sclerosis, spinal cord injuries, or other neurological diseases. Spasticity is a muscle problem characterized by tight or stiff muscles that may interfere with voluntary muscle movements.
How Does Baclofen Work?
Normally, muscles receive electrical signals via nerves to contract and relax. Spasticity is caused by an imbalance of electrical signals coming from the spinal cord through the nerves to the muscle. This imbalance causes the muscle to become hyperactive, resulting in involuntary spasms. Baclofen works by restoring the normal balance and reducing muscle hyperactivity. In this way, it allows for more normal muscle movements.
Baclofen can be taken orally as a pill or delivered directly into an area of the spine called the intrathecal space. The intrathecal space contains the cerebrospinal fluid -- the fluid surrounding the spinal cord and nerve roots. Often, MS patients receive intrathecal baclofen because oral baclofen causes unpleasant side effects, such as confusion, weakness, and sleepiness. Intrathecal baclofen delivers the drug right to the target site in the spinal cord. Because the drug does not circulate throughout the body, only tiny doses are required to be effective. Therefore, side effects are minimal.
What Is the Intrathecal Baclofen Pump System?
The intrathecal baclofen pump system is the way doctors deliver baclofen directly into the spinal fluid. The system consists of a catheter (a small, flexible tube) and a pump. The pump -- a round metal disc, about one inch thick and three inches in diameter -- is surgically placed under the skin of the abdomen near the waistline.
The pump stores and releases prescribed amounts of medicine through the catheter. With a programmable pump, a tiny motor moves the medication from the pump reservoir through the catheter. Using an external programmer, your treatment team can make adjustments in the dose, rate, and timing of the medication.
People with the pump must return to their doctor's office for pump refills and medication adjustments, typically every one to three months. The pump is taken out and replaced at the end of the battery's life span (which is usually five to seven years).