Pilot of Zinc Acetate to Improve Chronic Cough
Condition: Cough
MeSH terms: Cough
Intervention: Zinc Acetate 50 Mg Oral Capsule; Placebo oral capsule
Intervention description: Day 0 (randomization) to day 3 Zinc acetate 50 mg per day (one capsule)
Day 4 to day 7 If well tolerated: Zinc acetate 100 mg per day (two capsules)
Day 8 to V5 (6 weeks) If well tolerated: Zinc acetate 150 mg per day (three capsules); Day 0 (randomization) to day 3 Placebo (one capsule per day)
Day 4 to day 7 If well tolerated: placebo (two capsules per day)
Day 8 to V5 (6 weeks) If well tolerated: placebo (three capsules per day)
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 34.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Chronic cough; Refractory cough; Chronic refractory cough; Zinc; Zinc acetate

Summary:

      The Pilot of Zinc Acetate to Improve Chronic Cough (ZICO) is a study of 36 patients with
      chronic refractory cough that will be used to (1) assess if zinc acetate (150 mg/day) will
      improve patient reported measures of cough, (2) to establish if treatment with zinc acetate
      is well tolerated, and (3) to determine if the trial logistics are feasible.
    

Eligibility criteria:

        Inclusion Criteria:

          -  No upper or lower respiratory infection within 4 weeks

          -  Either

               -  Negative evaluation for:

                    -  Asthma; no symptoms of disease or no evidence of asthma based on spirometry
                       and/or methacholine challenge test

                    -  GERD: no symptoms of acid reflux disease or negative potential of hydrogen
                       (pH) probe

                    -  Rhinosinusitis/upper airway cough

        Or

          -  Cough persists despite treatment for the following:

               -  Asthma -treated for at least 8 weeks with at least medium dose inhaled
                  corticosteroids or with oral corticosteroids

               -  GERD - treated for at least 8 weeks with either a proton pump inhibitor (PPI) or
                  H2 blocker

               -  Upper airway disease, postnasal drip or sinusitis - treated for at least 8 weeks
                  with nasal steroids, antihistamines or both.

                    -  Non-smoker; defined as

          -  no smoking of any substance (e.g., tobacco, e-cigarette, marijuana) in the past 6
             months, and

          -  less than 20 pack-year smoking history

               -  Chest x-ray or CT scan in the past 12 months; negative for parenchymal lung
                  diseases (such as interstitial lung disease, idiopathic pulmonary fibrosis,
                  pneumonia, or TB) and negative for lung cancer

               -  Overall Cough Visual Analog Scale (Cough-VAS) score of 30 or higher

               -  Willing to halt use of zinc supplements or multivitamins containing zinc for the
                  duration of the study

               -  Provide written informed consent

        Exclusion Criteria:

          -  Marijuana use (smoking or ingestion of marijuana) in the past 6 months

          -  Use of ACE inhibitor currently or within the past 6 weeks

          -  Use of zinc supplements or multivitamins containing zinc currently or within the past
             6 weeks

          -  Occupational exposure to dust or chemicals that may cause cough, as determined by
             study physician

          -  Diagnosis or evidence of chronic obstructive pulmonary disease (COPD) as defined by
             forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) < 0.70 and
             FEV1% predicted < 80%

          -  History of lung disease, such as:

               -  Bronchiectasis

               -  Interstitial lung disease

               -  Sarcoidosis

               -  Pneumoconiosis

               -  Asbestosis

               -  Chronic mycobacterial infection

               -  Lung cancer

          -  History of pancreatitis

          -  Congestive heart failure

          -  Chronic kidney disease (creatinine clearance < 30ml/min)

          -  Pregnant or breast-feeding

          -  Other medical conditions that would interfere with participation in study