Efficacy of Two Doses of Duloxetine and Amitriptyline in Subjects With Refractory Chronic Cough

Chest radiograph or computed tomography (CT) of the thorax within the last 1 year not demonstrating any abnormality considered to be significantly contributing to the refractory chronic cough in the opinion of the Principal Investigator

Have a diagnosis of refractory chronic cough or unexplained cough for at least one year according to the American College of Chest Physicians guidelines

Have a score of ≥ 40mm on the Cough Severity VAS at Screening.

Women of child-bearing potential must agree to use 2 forms of acceptable birth control and make no donation of eggs from Screening through the end of the 8-week study period. Acceptable birth control methods include established use of oral, injected, or implanted hormonal methods of contraception; intrauterine device (IUD) or intrauterine system (IUS); tubal ligation; or male sterilization. Double-barrier method (diaphragm for female subject and condom for male partner with spermicidal) satisfies the requirement for 2 forms of acceptable birth control. When concordant with the preferred lifestyle of the subject, true and complete abstinence (not periodic abstinence) is acceptable.