Efficacy of Pregabalin on Chronic Cough

Efficacy of Pregabalin on Chronic Cough: A Double Blind, Randomized Control Trial Comparing Pregabalin With Placebo in Patients With Non-asthmatic Chronic Cough

The purpose of this study is to determine if Pregabalin, a medication used for the treatment of seizures and chronic pain, can be used to effectively treat people who suffer from non-asthmatic chronic cough (cough lasting over 8 weeks).

A significant number of patients have an impaired quality of life due to chronic cough that fails to respond to therapeutic efforts.

Research suggests that patients with chronic cough may have an oversensitive cough reflex. Reflexes are involuntary responses to nerve stimulation. Since standard cough medicines may not be helpful for treating the oversensitive cough reflex, treatment with neurologically acting agents has been investigated.

Existing work in treatment of cough of unknown etiology has focused on the use of Gabapentin, a compound that acts neurologically that is used in the treatment of epilepsy and pain. A similar drug, Pregabalin, may be a superior medication for this indication. Pregabalin is rapidly absorbed with peak blood concentrations within 1 hour, has an approximate bioavailability of 90%, and is 3 to 10 times more potent than Gabapentin and has no known pharmacokinetic drug interactions.

Inclusion Criteria:

• Diagnosis of non-asthmatic chronic cough defined as a cough experienced for a period of at least 8 weeks
• Negative methacholine challenge (within past year)
• Chest x-ray with absence of gross abnormality that could justify the cough or be a cause for the cough (within past 6 months)
• Male or female 18 years or older
• Willing and able to limit to 1 or less alcohol beverage per day (example: 360 ml of beer or 330 ml of cooler or 120 ml of wine)

Exclusion Criteria:

• Concurrent use of Gabapentin or Pregabalin for other indications (seizure disorder, chronic pain)
• History of allergy / intolerance or adverse effect with Gabapentin or Pregabalin.
• Concurrent use of central nervous system depressants (i.e. opioids or benzodiazepines)
• Not able to limit daily alcohol intake as recommended in the inclusion criteria
• Creatinine clearance < 60ml/min within past three months
• Current Smoker or has been quit less than 8 weeks
• Symptoms of post nasal drip
• History of gastroesophageal reflux. Only participants with untreated Gastroesophageal Reflux Disease (GERD) or less than 8 weeks of therapy will be excluded.
• Symptoms of upper airway cough syndrome
• ACE inhibitor use
• Allergy to citric acid
• Pregnant or nursing women
• History of angioedema or congestive heart failure