Intravenous infusion of 4-AP in chronic spinal cord injured subjects

Study design: A prospective double blind cross over trial of intravenous 4-Aminopyridine (4AP). Objective: To determine the efficacy of this drug in the treatment of spinal cord injured (SCI) patients for neurologic impairment, pain and spasticity. Setting: The post anesthesia care unit (PACU) of a tertiary care acute hospital. Methods: Twelve paraplegic patients were enrolled in a double blind cross over intravenous trial of 4-Aminopyridine (4-AP). Thirty milligrams of 4-AP or placebo were administered over a 2 h period. Patients were serially examined during and after the infusion clinically for pain, sensorimotor function, hypertonicity and motor control using electromyography (EMG). Samples of blood and cerebrospinal fluid (CSF) were also analyzed at similar intervals. Results: Despite penetration of 4-AP into the CSF, no significant differences were noted in the clinical and EMG parameters at the times measured. Individual changes in sensory function were reported by some patients in both the placebo and 4-AP trials, however mean values were not robust. Frequently, patients complained of -unpleasant symptoms during the 4AP infusion. Conclusion: The intravenous route may not, be the best way to administer this drug as no short term benefits were observed.