Plasma baclofen levels in children receiving continuous intrathecal baclofen infusion.

To determine the plasma baclofen concentrations of children undergoing continuous intrathecal baclofen infusion for treatment of cerebral spasticity, we assayed plasma samples from six children, 8 to 18 years of age, who were receiving intrathecal baclofen at constant rates of 77 to 400 micrograms/day. Plasma levels were at or below the limit of quantification (10 ng/mL) in all patients.