American Board of Internal Medicine (ABIM) Certification Practice Exam

Which medication is commonly used for treating spasticity in multiple sclerosis?

1. Pregabalin

2. Modafinil

3. Baclofen

4. Armodafinil

The correct answer is: Baclofen

Baclofen is commonly used to treat spasticity in multiple sclerosis because it is a muscle relaxant that works by inhibiting spinal reflexes. In multiple sclerosis, increased muscle tone and spasms are common due to disruption in the normal pathways for muscle control. Baclofen acts on the central nervous system to reduce spasticity, improving the quality of life for patients by increasing mobility and reducing pain stemming from muscle rigidity. The mechanism involves enhancing the inhibitory effects of GABA, a neurotransmitter that helps reduce neuronal excitability. By directly affecting the spinal cord circuits that mediate muscle tone and reflexes, Baclofen helps relieve the symptoms of spasticity. It is often preferred for managing this condition in multiple sclerosis patients due to its effectiveness and relatively favorable side effect profile. Other medications listed, such as Pregabalin and Modafinil, have different indications. Pregabalin is typically used for neuropathic pain and seizure disorders, while Modafinil and Armodafinil are used primarily to promote wakefulness in conditions like narcolepsy and are not indicated for muscle spasticity. Thus, Baclofen stands out as the primary choice for managing spasticity in multiple sclerosis.