Evidence Summary

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In people with unexplained chronic cough, speech therapy is recommended and gabapentin may be considered

Gibson P, Wang G, McGarvey L, et al. Treatment of Unexplained Chronic Cough: CHEST Guideline and Expert Panel Report. Chest. 2016;149:27-44.

Review question

In people with unexplained chronic cough, do any treatments improve symptoms?


Unexplained chronic cough is a cough for which an underlying medical problem cannot be found and that does not go away, even with a doctor’s testing and treatment. It could go on for years and affects people’s quality of life.

How the review was done

16 studies (11 randomized controlled trials and 5 systematic reviews) were published up to April 2014.

The randomized controlled trials included 567 people, mostly women, who had an average age of 52 years.

All had chronic coughs that had lasted an average of about 2.6 years.

What the researchers found

4 recommendations are described in the Table below.

Unfortunately, the quality of evidence is low.


In people with unexplained chronic cough, speech therapy is recommended, and gabapentin may be considered. The strength of recommendations for treatment of unexplained chronic cough is weak.

Treatment vs placebo or no treatment in people with unexplained chronic cough



People with unexplained chronic cough should try speech therapy.

1 study of 87 people found that speech therapy improved cough severity compared with no treatment.

People with unexplained chronic cough should not use inhaled corticosteroids.

1 study of 50 people (who had allergic asthma ruled out as a cause) found that inhaled corticosteroids did not affect cough severity compared with placebo.

People with unexplained chronic cough should try gabapentin if they decide that it is worth the potential side effects; the decision should be re-assessed after 6 months.

1 study of 62 people found that gabapentin improved quality of life compared with placebo. 31% of people treated with gabapentin and 10% of people given placebo had side effects.

People with unexplained chronic cough who do not have gastric acid reflux disease should not use proton-pump inhibitors.

1 study of 40 people found that a proton-pump inhibitor did not improve cough severity or quality of life compared with placebo.

*All recommendations are weak.

Related Topics


A harmless, inactive, and simulated treatment.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

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