Study on the effect of theobromine in suppression of cough
Research type
Research Study
Full title
Two-part, adaptive, double-blind, randomised, placebo-controlled efficacy study of theobromine in healthy volunteers to investigate the effect of theobromine on citric acid-induced and capsaicin-induced cough (Cough Challenge)
IRAS ID
218109
Contact name
Mark Thomas
Contact email
Sponsor organisation
Infirst Healthcare Ltd
Eudract number
2016-003776-43
Duration of Study in the UK
0 years, 6 months, 23 days
Research summary
Infirst Healthcare Limited are developing a drug containing theobromine for the treatment of dry cough. This study will compare the effects of theobromine and placebo (a ‘dummy drug’ containing no active ingredients) on cough sensitivity in healthy volunteers.
Theobromine is a well-known molecule which is similar to caffeine and theophylline and can be found in chocolate as well as other foods.
Cough sensitivity will be measured using cough challenges, which are proven methods of inducing a cough in humans and involve inhaling cough stimulating substances through the mouth. In this study two different cough stimulating substances Capsaicin, an extract of hot pepper, and Citric acid, the acid commonly found in fruit such as lemons will be inhaled orally at standard doses used in previous studies, which have been found to be very safe and free of any serious side effects.
This study is split into 2 parts with the citric acid cough challenge performed in Part 1 and the capsaicin challenge performed in Part 2. Subjects will be asked to participate in both parts and will receive two treatments in a random order;
• Treatment A: Theobromine 300mg taken as a single capsule in the morning and evening on Day 1 and in the morning on Day 2 (total 3 doses).
• Treatment B: Placebo taken as a single capsule in the morning and evening on Day 1 and in the morning on Day 2 (total 3 doses).Data from Part 1 will be analysed, if the study aims are met in Part 1, Part 2 will not be performed.
It is expected that approximately 24 participants will take part in Part 1 and Part 2 of the study at a single UK centre, the Medicines Evaluation Unit (MEU), and it is planned for approximately equal numbers of male and female subjects to be enrolled.
REC name
North West - Greater Manchester Central Research Ethics Committee
REC reference
16/NW/0798
Date of REC Opinion
23 Jan 2017
REC opinion
Further Information Favourable Opinion