Iron Repletion in Chronic Cough and Iron Deficiency

Study Overview
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Brief Summary
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Chronic cough is more frequent and severe in women than in men. Women often have decreased iron stores, due to menses and pregnancies. Aim of the study: to investigate if iron deficiency has a role in chronic cough by favouring airway hypersensitivity to inhaled irritants.

Detailed Description
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Women with chronic cough and iron deficiency, cough unresponsive to empiric treatment (suggested by cough guidelines) with antiH1-histaminic drug plus proton pump inhibitor. Cough VAS (score from 1,best, to 5, worst). Histamine inhalation challenge, performed to assess bronchial, laryngeal, and cough thresholds, performed by delivering doubling concentrations, from 0.5 mg/ml up to 32 mg/ml, by a nebulizer. After each dose FEV1, as bronchial index, maximum mid-inspiratory flow (MIF50) as laryngeal index, and coughs number are assessed. Bronchial threshold is the concentration causing 20% decrease in FEV1, laryngeal threshold that causing 25% decrease in MIF50, cough threshold that causing 5 coughs. Histamine hyperresponsiveness of the bronchi (BHR), larynx (LHR) and cough (coughHR) are defined for thresholds equal or below 8 mg/ml. Histamine thresholds and cough VAS obtained in baseline, after cough empiric treatment with antiH1-histaminic and proton pump inhibitor, and after iron supplementation.

Official Title
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Effect of Iron Repletion in Women With Chronic Cough and Iron Deficiency

Conditions
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Cough, Laryngeal Disease, Bronchial Disease, Iron Deficiency

Intervention / Treatment
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* Drug: iron sulphate
* Drug: antiH1-histamine, proton pump inhibitor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Unexplained cough : no detectable trigger for chronic cough identified, such as persistent rhinitis, chronic sinusitis, gastroesophageal reflux disease and asthma. no benefit by prior treatment with antiH1-histaminic drug and proton pump inhibitor. iron deficiency. normal lung function tests and chest radiography no relevant systemic disease. no acute respiratory infection in the last eight weeks. no pharmacological treatment in the last two weeks. Exclusion Criteria:

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: iron sulphate|1 or 2 330 mg/daily iron sulphate oral tablets|
|Drug: antiH1-histamine, proton pump inhibitor|This is not an intervention of interest, but it is a selection criterion to define unexplained cough, as suggested by cough guidelines.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in cough VAS | Changes in cough VAS after 2 months iron supplementation (1 mg/kg elemental iron, corresponding to one or two 330 mg iron sulphate tablets)compared to the value observed after empiric treatment Cough VAS from 0 (best= no cough) to 5 (worst = severe cough) | after 2 months empiric treatment and 2 months iron supplementation | 
| Change in laryngeal histamine threshold | Change in laryngeal threshold, assessed as the histamine concentration causing 25% decrease from baseline of MIF50 (PC25MIF50), after 2 months iron supplementation (1 mg/kg elemental iron, corresponding to one or two 330 mg iron sulphate tablets), compared to the value obtained after empiric treatment | after 2 months empiric treatment and 2 months iron supplementation | 
| Change in cough histamine threshold | Change in cough threshold, assessed as the histamine concentration causing 5 or more coughs(PC5cough), after 2 months iron supplementation (1 mg/kg elemental iron, corresponding to one or two 330 mg iron sulphate tablets), compared to the value obtained after empiric treatment | after 2 months empiric treatment and 2 months iron supplementation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in bronchial histamine threshold | Change in bronchial threshold, assessed as the histamine concentration causing 20% decrease from baseline of FEV1 (PC20FEV1), after 2 months iron supplementation (1 mg/kg elemental iron, corresponding to one or two 330 mg iron sulphate tablets), compared to the value obtained after empiric treatment | after 2 months empiric treatment and 2 months iron supplementation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cough, Laryngismus, Bronchial spasm, Deficiency diseases