A Losartan Dream for COPD

Angiotensin Receptor Blockers (ARB)

Angiotensin Receptor Blockers (ARB) are a class of drugs used to treat hypertension in patients. A previous study by Mancini, et al, looked at patients with heart disease and COPD who were treated with statins, angiotensin-converting enzymes (ACE), ARB, or a combination of statins and ACE or ARB medications. New research is looking into patients who take one of these drugs, specifically Losartan, an ARB, due to its anti-inflammatory properties. 

These clinical trials have been looking at the use of Losartan in patients with COPD who have smoked. The trials are looking to see if Losartan helps to reduce the airway inflammation and mucus secretion caused by cigarette smoke. One such study looked to see if Losartan would decrease the mucous concentration by cutting down inflammation and removing mucus from the lungs. 

The Mancini trial found that patients benefited when using either statins, ACE, ARB, or a combination of statins and ACE or ARB. The use of the combination of drugs saw the greatest benefits in reducing COPD hospitalization and mortality. 

A study by Dr. Kim, et al, looked at the effects of Losartan on human bronchial epithelial cells. The results showed that Losartan decreased airway inflammation and mucus amounts to levels seen in normal mucociliary clearance patients in vitro. The study showed that whether the cells were from smokers with or without COPD, improvements in mucociliary function were seen with smoke exposure. This study confirmed findings that were previously seen in trials on mice, suggesting that Losartan could be effective with chronic airway disease caused by cigarette smoke in reducing inflammation and mucus secretions.

Another pilot study evaluated whether Losartan slows the progression of  emphysema. The study included 106 patients, 46 with emphysema and 60 with less severe COPD, who were current or former smokers with at least a 10 pack-year history. Patients with prior use of ACE or ARB were excluded. The Losartan group took 100 mg each day for one year and was assessed with a CT scan of the lung at the start, 6-month mark, and 12-month mark. In the group taking Losartan, there was a 0.72% regression of right-middle lobe emphysema compared to a 3.34% progression in the placebo group. There also reported a 0.32% reduction in emphysema overall in the Losartan group compared to the placebo group that showed a 2.18% progression, although this did not reach statistical significance. 

The Losartan Effects on Emphysema Progression (LEEP) Trial will look to definitively determine whether Losartan slows emphysema progression in patients with COPD through high resolution CT scan. Results of this study are forthcoming. 

With Losartan showing improvements in patients with COPD, there is a strong chance that its use will continue to grow. The ability to slow emphysema and chronic bronchitis, with the possibility of regression, will aid patients in being able to stay out of the emergency room and hospital, decreasing the overall costs of care. And while there will be limitations and exclusions for patients who qualify for treatments, being able to tell patients that there is hope is exciting.