Primary Lateral Sclerosis Medication

Updated: Sep 06, 2019
  • Author: Carmel Armon, MD, MSc, MHS; Chief Editor: Nicholas Lorenzo, MD, CPE, MHCM, FAAPL  more...
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Medication Summary

Medications to alleviate spasticity are discussed here. Patients in whom oral medications do not provide adequate spasticity relief may wish to consider intrathecal baclofen (ie, via continuous infusion pump).


Skeletal muscle relaxants

Class Summary

These agents are used to treat reversible spasticity associated with MS or spinal cord lesions and are useful also in patients with spasticity due to PLS. Individual responses vary.

Baclofen (Lioresal, Gablofen)

This agent may induce hyperpolarization of afferent terminals and inhibit monosynaptic and polysynaptic reflexes at the spinal level.


Alpha2 Adrenergic Agonists

Class Summary

These agents act to decrease excitatory input to alpha motor neurons.

Tizanidine (Zanaflex)

This centrally acting muscle relaxant is metabolized in the liver and excreted in urine and feces.



Class Summary

These agents may act in the spinal cord to induce muscle relaxation.

Diazepam (Valium)

Diazepam depresses all levels of the central nervous system (eg, limbic and reticular formation), possibly by increasing activity of gamma-aminobutyric acid (GABA). Individualize the dosage and increase it cautiously to avoid adverse effects.

Clonazepam (Klonopin)

Clonazepam is a long-acting benzodiazepine that increases presynaptic GABA inhibition and reduces the monosynaptic and polysynaptic reflexes. It suppresses muscle contractions by facilitating inhibitory GABA neurotransmission and other inhibitory transmitters.