Effects of Oral Mucolytics on Tear Film and Ocular Surface
Condition: In the Present Study, we Investigated the Effects of Oral Ambroxol on Tear Film and Ocular Surface.
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      Ambroxol is a metabolite of bromhexine and possesses mucokinetic and secretolytic properties
      that are also found in mucolytic agents.1 Ambroxol has been used for decades for the
      treatment of respiratory disorders associated with excessive mucus, including chronic
      inflammatory pulmonary conditions, bronchitis, and pneumonia.2,3 The drug changes the
      biophysical properties of secretions by degrading the mucin polymers, deoxyribonucleic acid,
      fibrin in airway secretions, and by generally decreasing viscosity.4 In addition, ambroxol
      increases cyclic nucleotide (cAMP or cGMP),5 which can theoretically increase tear
      secretion.6 Many systemic medications, such as antihistamines, antidepressants, diuretics,
      acne drugs, and certain blood pressure medicines can cause or exacerbate a dry eye.7,8 On the
      other hand, several topical medications, including mucolytics such as ambroxol and
      bromhexine, may be used to treat tear-deficient dry eyes by promoting lacrimal gland
      function.9 However, the effects of mucoactive agents on the tear film have not been
      investigated systemically, and mucoactive agents may have a disturbing effect on the tear
      film because they modify mucin.10,11 The tear film is composed of 3 unique layers, including
      the outermost lipid layer, the middle aqueous layer, and the innermost mucus layer; this
      structure enables it to perform many functions.12 The lipid layer acts as a barrier to
      prevent tear film evaporation, and the aqueous layer supplies oxygen and important nutrients
      to the cornea.13 The mucin layer, secreted mostly by conjunctival goblet cells, coats the
      corneal surface rendering it hydrophilic, and anchors the tear film to the corneal surface.14
      Deficiencies in the amount of tear production or alteration in tear composition can lead to
      ocular surface disease.15 Although many studies have focused on aqueous-deficient dry eye
      syndrome,16-18 the effect of mucin layer defects on the tear film has not been thoroughly
      studied. Furthermore, very few reports have determined the effects of oral mucolytic agents
      on the tear film and ocular surfaces, although a study has reported that filamentary
      keratopathy was treated with debridement of filaments and application of topical mucolytic
      agents such as acetylcysteine eyedrops. In the present study, we investigated the effects of
      oral ambroxol on tear film and ocular surface.

      Reference

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Intervention name(s): Ambroxol hydrochloride (Mucopect®, 60 mg, Boehringer Ingelheim)
Intervention type(s): Drug
Intervention MeSH terms: Ambroxol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Health Services Research