Addition of Amitriptyline or Placebo to Speech Pathology for Inducible Laryngeal Obstruction: A Double-Blind Randomized Controlled Trial.

Abstract

The impact of inducible laryngeal obstruction (ILO) is significant, supporting the importance of determining effective treatments. Double-blind randomized controlled trial examining the addition of amitriptyline to speech pathology (SP) for ILO. Adults aged 18 to 85 years with ILO diagnosed on laryngoscopy were randomized to amitriptyline (target maintenance dose of 75 mg daily) or placebo, in combination with six SP sessions. We assessed ILO symptom severity and frequency using the Vocal Cord Dysfunction Questionnaire (VCDQ) and Dyspnea Index (DI), respectively. Co-primary outcomes were the difference in posttreatment VCDQ and DI scores between groups, adjusted for baseline scores and analyzed per protocol. Target recruitment was 50 participants to provide 46 for analysis, assuming 8% dropout. Twenty-one participants were randomized to SP plus amitriptyline, and 20 to SP plus placebo. Three participants dropped out, leaving 19 per group for analysis. There were no differences in posttreatment ILO symptom severity (VCDQ) or frequency (DI) between groups; VCDQ 37.35 (95% CI, 32.54-42.17) for SP plus amitriptyline versus 38.12 (95% CI, 33.31-42.94) for SP plus placebo (P = .82); and DI 15.96 (95% CI, 12.24-19.68) for SP plus amitriptyline versus 16.52 (95% CI, 12.79-20.24) for SP plus placebo (P = .83). There were significant improvements in posttreatment mean scores compared with baseline scores in ILO symptom severity (VCDQ) and frequency (DI) in both groups. The minimal clinically important difference on ILO symptom questionnaires (VCDQ and/or DI) was achieved in 28 of 38 participants (73.7%). In this trial, speech pathology effectively reduced ILO symptom severity and/or frequency in 73.7% of participants, with no additional benefit from concurrent amitriptyline.