Comment
Author: Admin | 2025-04-28
Starting PO baclofen, experts recommend starting oral baclofen at the lowest dose, 2.5-5 mg three times daily.16 The dose can be escalated every three days, to a maximum of 60-80 mg a day.15 If the patient does not show a response within six weeks of starting the maximum dose, or the side-effects are not tolerable, then the PO baclofen trial should be tapered and discontinued. Another antispastic muscle relaxant or intrathecal (IT) baclofen can be trialed.15While PO baclofen does cross the blood brain barrier, due to the low lipid solubility and hydrophilicity of baclofen, only a small percentage of PO baclofen is able to act on the spinal cord.12 By infusing baclofen into the subarachnoid space, GABA inhibition of baclofen can act directly on the spinal cord, at lower doses than PO baclofen. Thus, IT baclofen can be given at 1% of the PO dose, resulting in a lower incidence of cerebral side-effects and a higher reduction in spastic muscle tone than PO baclofen.12 Intrathecal baclofen has been shown to reduce spasticity in children with CP but is considered a surgical procedure that carries potential catheter-related complications (infection, CSF leaks, catheter malfunction, etc.).16 Prior to placement of an intrathecal baclofen pump, patients must have chronic intractable spasticity, and have been unresponsive or intolerant to a minimum six-week course of PO baclofen therapy.12 In addition, patients must demonstrate a positive response to a test dose of IT baclofen prior to implantation of a continuous infusion pump. Of note, the size of the intrathecal baclofen pump requires a body habitus of at least 15 kgs for placement.12Dantrolene Dantrolene inhibits the ryanodine receptor complex resulting in reduced activation by calmodulin and calcium thereby inhibiting the voltage-dependent activation of calcium release in skeletal muscle.5 Dantrolene is approved to treat malignant hyperthermia and spasticity in upper neuronal disorders such as cerebral palsy, spinal cord injury, and multiple sclerosis. In pediatrics, dantrolene is initiated at 0.5mg/kg daily and increased weekly to a maximum of 12mg/kg/day or 400 mg a day, whichever is lower, in divided doses.17 However, due to the black box warning for hepatotoxicity associated with chronic use, dantrolene is not generally used long-term.18 Side-effects of dantrolene include muscle weakness, drowsiness, dizziness, malaise, and diarrhea.5 Carisoprodol Carisoprodol is an antispasmodic muscle relaxant with high abuse potential and thus is infrequently prescribed. Side-effects of carisoprodol include dizziness, drowsiness, headache, and rare idiosyncratic reactions that include transient quadriplegia and mental status changes.1 Carisoprodol can cause withdrawal symptoms with abrupt discontinuation.5 Of note, carisoprodol is contraindicated in acute intermittent porphyria. Cyclobenzaprine Cyclobenzaprine is similar in structure to tricyclic antidepressants (TCAs). Cyclobenzaprine inhibits 5-HT2 receptors in the ventral spinal cord, thereby inhibiting tonic alpha-motor neuron excitation.5 Cyclobenzaprine may also
Add Comment