The two most common symptoms of Idiopathic Pulmonary Fibrosis are cough and shortness of breath. Other symptoms that are often present but not specific to IPF are fatigue and gradual unintended weight loss.
Cough – A Symptom of Idiopathic Pulmonary Fibrosis
Cough is one of the most common reasons that people seek medical care. Millions of doctor visits each year are for cough. The majority are for cough related to respiratory infections. However, the cough of an upper respiratory infection should resolve in less than 8 weeks for the vast majority of patients. Cough lasting more than 12 weeks requires another explanation.
In health, cough is an important normal part of your lung function. It serves to clear debris from the airways. However, the cough reflex can become problematic under many circumstances. In IPF the cough is felt to be directly related to the fibrotic or scarring process in the lungs. In contrast in other lung diseases such as asthma or post nasal drip the cough is a reflex that becomes overactive related to airway irritation.
More than a billion dollars are spent annually on medicines for cough and throat symptoms. Most of this is over the counter preparations. The most common agents are used for acute cough or cough of less than a couple of month’s duration. This is usually caused by respiratory viruses that result in a “cold”. Common preparations include guaifenesin (the active ingredient in Mucinex and many Robitussen preparations.) and diphenhydramine (the active ingredient in many “cold and sinus” medicines).
Cough that lasts more than 3 months
Everyone that has chronic cough (cough lasting more than 3 months) should have a chest xray to make sure that there is no underlying lung problem. If the xray is normal then we start to think about a small number of very common problems. First we look for medicines that can cause cough. A common blood pressure medicine family (ace inhibitors) may cause cough in 5-20% of patients and it is important to consider this in patients using this family of medicines. The treatment is stopping the offending medication. A similar family of medicines called angiotensin receptor blockers may be substituted.
Another very common cause of chronic cough is gastroesophageal reflux disease or GERD. As Americans have gotten heavier and our diets have become full of fast foods (=high fat foods) there is a growing epidemic of heart burn or GERD symptoms. In some patients this can lead to a chronic cough. Some patients may not have symptoms that they recognize as heartburn and only have the cough. The best treatment is to change your diet (remove all caffeine, chocolate, citrus including tomato, avoid fatty foods, avoid late meals), lose weight and sleep with your head of bed elevated about 10 inches. Over the counter medicines that block or suppress acid are also important. There are two families of medicines that suppress acid production. H2-Blockers include famotidine (Pepcid), ranitidine (Zantac), and cimetidine (Tagamet). The proton pump inhibitors include omeprazole (Prilosec), pantoprazole (Protonix) and many others.
The third major cause of chronic cough is a type of asthma called cough-variant asthma. In contrast to usual asthma, patients don’t wheeze. Instead they cough. Asthma treatments are very effective for this type of cough.
Cough in Idiopathic Pulmonary Fibrosis
The cough associated with IPF is dry (nonproductive) and a common cause of great frustration for patients. It is often described as a hacking cough. Patients may have cough long before they complain of any other symptoms. In contrast to the above causes of chronic cough, there is no specific treatment. We don’t have a medicine that effectively addresses the stimuli at its cause. We do have a long list of medicines that can be tried with variable effect. My usual practice is to work my way through the different agents seeing if one or another works well for each patient.
- Guaifenesin: this comes by itself and with many potential additives. This is a very good first line agent.
- Dextromethorphan: This is a centrally acting cough suppressant. It may cause fatigue or in some patients constipation.
- Pseudoephedrine: this is not a great long term choice as it raises blood pressure. I would avoid this agent for chronic cough.
- Phenergan: This is a sedating antiemetic (anti-nausea medicine). It suppresses cough largely by making patients sleepy. I do not prescribe this medication for more than a brief time. Long term use can lead to a permanent neurologic disorder called tardive dyskinesia.
- Benzonatate (Tessalon Pearls): one of the more effective agents. Taken as a pill that is swallowed three times a day, some patients find it quite effective.
- Narcotic agents such as codeine: Narcotics act on the brain to suppress the cough reflex. Disadvantages include sedation, constipation and dependence. I only prescribe this family for very brief periods of time.
- Prednisone: some patients have good cough suppression at 10mg per day of prednisone. The prednisone is not treating the underlying disease. Patients should thoroughly discuss with their doctors the pros and cons. Chronic prednisone has many side effects such as diabetes, bone thinning, cataracts and an increased risk of infections and weight gain.
- Thalidomide: There are a small number of research studies that have suggested that Thalidomide might be effective. I reserve this agent for the most difficult cases. Women who might become pregnant must meticulously avoid any contact with this medication as it causes severe birth defects.
Shortness of Breath Associated with Idiopathic Pulmonary Fibrosis
The shortness of breath associated with IPF is slowly progressive, it gradually worsens over time. The progression is not always steady though, and there may be periods of stability or sharp declines. Patients generally notice shortness of breath or dyspnea with strenuous activities. They may relate the onset to a viral upper respiratory infection or a trip where they had to walk up stairs or steep inclines. Universally, by the time patients notice shortness of breath their pulmonary fibrosis has probably been present for many months if not years. By the time patients present with shortness of breath pulmonary function tests (PFTs) are always abnormal and chest imaging is clearly abnormal. As IPF becomes more severe so does the dyspnea. Eventually patients may be short of breath with activities of daily living such as showering and dressing or even at rest.