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Rococo study: a real-world evaluation of an over-the-counter medicine in acute cough (a multicentre, randomised, controlled study)
  1. S S Birring1,
  2. J Brew2,
  3. A Kilbourn2,
  4. V Edwards2,
  5. R Wilson3,
  6. A H Morice4
  1. 1Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
  2. 2Infirst Healthcare Ltd, London, UK
  3. 3Spica Consultants Ltd, Marlborough, UK
  4. 4Hull York Medical School, Castle Hill Hospital, East Yorkshire, UK
  1. Correspondence to Dr SS Birring; surinder.birring{at}


Objectives To investigate the efficacy and safety of CS1002, an over-the-counter cough treatment containing diphenhydramine, ammonium chloride and levomenthol in a cocoa-based demulcent.

Design A multicentre, randomised, parallel group, controlled, single-blinded study in participants with acute upper respiratory tract infection-associated cough.

Setting 4 general practitioner (GP) surgeries and 14 pharmacies in the UK.

Participants Participants aged ≥18 years who self-referred to a GP or pharmacist with acute cough of <7 days' duration. Participant inclusion criterion was cough severity ≥60 mm on a 0–100 mm visual analogue scale (VAS). Exclusion criteria included current smokers or history of smoking within the past 12 months (including e-cigarettes). 163 participants were randomised to the study (mean participant age 38 years, 57% females).

Interventions Participants were randomised to CS1002 (Unicough) or simple linctus (SL), a widely used cough treatment, and treatment duration was 7 days or until resolution of cough.

Main outcome measures The primary analysis was intention-to-treat (157 participants) and comprised cough severity assessed using a VAS after 3 days' treatment (prespecified primary end point at day 4). Cough frequency, sleep disruption, health status (Leicester Cough Questionnaire (LCQ-acute)) and cough resolution were also assessed.

Results At day 4 (primary end point), the adjusted mean difference (95% CI) in cough severity VAS between CS1002 and SL was −5.9 mm (−14.4 to 2.7), p=0.18. At the end of the study (day 7) the mean difference in cough severity VAS was −4.2 mm (−12.2 to 3.9), p=0.31. CS1002 was associated with a greater reduction in cough sleep disruption (mean difference −11.6 mm (−20.6 to 2.7), p=0.01) and cough frequency (mean difference −8.1 mm (−16.2 to 0.1), p=0.05) compared with SL. There was greater improvement in LCQ-acute quality of life scores with CS1002 compared with SL: mean difference (95% CI) 1.2 (0.05 to 2.36), p=0.04 after 5 days' treatment. More participants prematurely stopped treatment due to cough improvement in the CS1002 group (24.4%) compared with SL (10.7%; p=0.02). Adverse events (AEs) were comparable between CS1002 (20.5%) and SL (27.6%) and largely related to the study indication. 6 participants (7%) in the CS1002 group reduced the dose of medication due to drowsiness/tiredness, which subsequently resolved. These events were not reported by participants as AEs.

Conclusions Although the primary end point was not achieved, CS1002 was associated with greater reductions in cough frequency, sleep disruption and improved health status compared with SL.

Trial registration number EudraCT number 2014-004255-31.

  • Controlled clinical trial
  • Cough
  • Demulcent
  • Diphenhydramine
  • Simple Linctus

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

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  • Contributors SB, JB, AK, VE, RW and AM were involved in conception and design of work. RW, VE and JB were involved in data analysis. All authors were involved in data interpretation. SB was involved in drafting the manuscript with input from JB, AK, VE, RW and AM. All authors were involved in review and approval of the manuscript.

  • Funding The study was funded by Infirst Healthcare and Infirst Healthcare is the manufacturer of CS1002 (Unicough).

  • Competing interests SSB has received personal fees from Infirst Healthcare during the conduct of the study for advisory work. AHM has received personal fees from Infirst Healthcare during the conduct of the study for advisory work. JB, VE and TK are employees of Infirst Healthcare. RW is a statistical consultant to Infirst Healthcare.

  • Ethics approval North West—Greater Manchester South Research Ethics Committee (Reference: 14/NW/1424).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional data are available.