Which drug is a central acting skeletal muscle relaxant that might be prescribed for multiple sclerosis–related spasticity?

Which drug is a central acting skeletal muscle relaxant that might be prescribed for multiple sclerosis–related spasticity?

• A. Baclofen
• B. Dantrolene
• C. Diazepam
• D. Methocarbamol

Answer: (A)

Central acting skeletal muscle relaxants aimed at MS-related spasticity work by dampening spinal reflexes to reduce tone. Baclofen fits this role best because it’s a GABA-B receptor agonist in the spinal cord. Activation of these receptors hyperpolarizes nerve cells and lowers the release of excitatory signals to alpha motor neurons, which decreases the stretch reflex and spasticity. It can be given orally or, for severe cases, intrathecally via a pump to target the spinal cord with fewer systemic effects. Dantrolene acts peripherally on the muscle itself by blocking calcium release from the sarcoplasmic reticulum, so it doesn’t address central reflex pathways. Diazepam and methocarbamol are also CNS depressants but aren’t the first-line targeted for MS spasticity due to sedative effects and other risks.

Central acting skeletal muscle relaxants aimed at MS-related spasticity work by dampening spinal reflexes to reduce tone. Baclofen fits this role best because it’s a GABA-B receptor agonist in the spinal cord. Activation of these receptors hyperpolarizes nerve cells and lowers the release of excitatory signals to alpha motor neurons, which decreases the stretch reflex and spasticity. It can be given orally or, for severe cases, intrathecally via a pump to target the spinal cord with fewer systemic effects.

Dantrolene acts peripherally on the muscle itself by blocking calcium release from the sarcoplasmic reticulum, so it doesn’t address central reflex pathways. Diazepam and methocarbamol are also CNS depressants but aren’t the first-line targeted for MS spasticity due to sedative effects and other risks.