A Study of the Effect of 20 mg Ambroxol Hydrochloride on Acute Cough.
Condition: Cough
MeSH terms: Cough
Study type: Interventional
Phase: Phase 2

Summary: 
      To assess the effect of a single doses of 20 mg ambroxol hydrochloride on cough reflex
      sensitivity to citric acid, capsaicin, adenosine triphosphate (ATP) and distilled water in
      patients with acute cough related to upper respiratory tract infection
    

Detailed description: 
      Cough is the 5th most common presenting complaint in adults. Cough results from the
      stimulation of two types of afferent pathways whose receptors are located within the airway
      epithelium. These include rapidly adapting receptors (RARs) and C-fibre receptors. Acute as
      well as chronic, non-productive cough, which often follow viral upper respiratory tract
      infection, may result from increased sensitivity of the cough reflex. Relatively little
      research has been done to gain insight into the mechanisms of cough in health and disease,
      and to properly evaluate potential antitussive therapies. Indeed, little consensus exists
      regarding the optimal treatment of acute cough because of the lack of standardised outcome
      measures for cough. Possibly the most significant clinical need in terms of cough therapy is
      for the cough associated with an acute upper respiratory tract infection (URTI). Although the
      cough associated with URTI is often self-limiting and resolves within several days, it
      undoubtedly accounts for a major proportion of huge worldwide expenditure of over-the-counter
      (OTC) cough and cold products where patients are still struggling to find an effective
      medication.

      This exploratory study will enable us to identify the cough challenge agent (CCA) that is
      most sensitive to the effect of ambroxol on cough reflex. This is expected to provide a
      reproducible response, to use in future studies.

      This will be an open label, study in subjects with acute cough associated with URTI.

      There will be a Screening/Baseline and combined Treatment visit. Subjects will return
      approximately 1-4 weeks after their treatment once all symptoms have subsided and the subject
      is no longer suffering from URTI, for a Follow-up Visit.

      Up to 14 subjects with acute cough in relation to a URTI and who meet all entry criteria will
      be assigned to:

      Treatment p.o 20 mg ambroxol lozenge (Lysopain Ambr MintM)

      At Baseline and post treatment, cough sensitivity will be measured by standard clinical
      methodology incorporating a series of four cough challenges (citric acid, capsaicin, ATP and
      distilled water).

      Screening/baseline visit 1a The Screening and Baseline visit will ensure that each subject
      meets all the specified inclusion and none of the exclusion criteria.

      Treatment phase visit 1b Subjects who satisfy all entry criteria at baseline will be
      administered 20 mg ambroxol in the form of a lozenge which must be sucked until fully
      dissolved in the mouth.

      The treatment will be administered in the afternoon of the same visit day as the
      screening/baseline assessments.

      The series of abbreviated cough challenges will be conducted at 30 min and 90 min post dose.

      Telephone contact Patients will be contacted by telephone once a week to determine if all
      symptoms associated with URTI have abated. Once this is confirmed patient will be booked in
      for the follow-up visit.

      Follow-Up Phase Subjects will return within 4 weeks after treatment for a Follow-Up Visit
      once symptoms of URTI have abated. A series of full cough challenges will be performed at
      this vist to determine reduction in cough hypersensitivity.
    

Intervention name(s): Ambroxol Hydrochloride
Intervention type(s): Drug
Intervention description(s): single lozenge of 20mg ambroxol
Other intervention name(s): Lysopain Ambr Mint™
Intervention MeSH terms: Ambroxol
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: acute