Pilot of Zinc Acetate to Improve Chronic Cough

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.

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

Conditions:
• Cough