Baclofen-induced cough suppression in cervical spinal cord injury.
OBJECTIVE
To determine the effect of the GABA-agonist baclofen on cough reflex sensitivity in subjects with cervical spinal cord injury (C-SCI). Baclofen has been shown to inhibit the cough reflex in able-bodied volunteers.


METHODS
Prospective, nonrandomized control trial.


METHODS
Veterans Affairs medical center with large outpatient SCI population.


METHODS
Twelve adult males (11 outpatients) with C-SCI chronically maintained on oral baclofen for the treatment of muscle spasm.


METHODS
Subjects underwent cough challenge testing with inhaled capsaicin. The concentrations (microM) of capsaicin inducing 2 or more (C2) and 5 or more (C5) coughs were determined. Mean values for log C2 and log C5 were compared with a control group of outpatients with C-SCI not receiving baclofen.


RESULTS
Subjects treated with baclofen had a significantly higher cough threshold (diminished cough reflex sensitivity) than control subjects. Mean (+/- standard error of the mean) values for log C2 in study subjects and controls were 1.28 +/- .16 and .65 +/- .15, respectively (p = .009). Mean values for log C5 in subjects receiving baclofen and in control subjects were 2.20 +/- .22 and 1.43 +/- .23, respectively (p = .024). Subjects and controls did not differ in terms of age, spirometric parameters, or duration of injury.


CONCLUSIONS
The results suggest that chronic therapy with baclofen diminishes cough reflex sensitivity in subjects with C-SCI. The clinical significance of this finding remains to be elucidated.
Dicpinigaitis
P V
PV
Department of Medicine, Albert Einstein College of Medicine, and the Spinal Cord Pulmonary Research Center, Veterans Affairs Medical Center, Bronx, NY, USA.
Grimm
D R
DR
Lesser
M
M
D000328:Adult; D001418:Baclofen / Q000494:pharmacology*; D003371:Cough / Q000503:physiopathology*; D018755:GABA Agonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012018:Reflex / Q000187:drug effects*; D013119:Spinal Cord Injuries / Q000503:physiopathology*
D018755:GABA Agonists; D001418:Baclofen