FDA reviewers recommend approval of Bayer hypertension drug By Toni Clarke Fri Aug 2, 2013 12:07pm EDT (Reuters) - Bayer AG's experimental drug to treat two types of pulmonary hypertension worked well in clinical trials and should be approved, but at lower doses than those proposed by the company, according to medical reviewers at the U.S. Food and Drug Administration. The reviewers posted their report on the agency's website in preparation for a meeting on Tuesday of outside medical experts who will make their own recommendation on whether the FDA should approve the drug, riociguat. If approved, the drug would be sold under the brand name Adempas. It is designed to improve the ability of patients with chronic thromboembolic pulmonary hypertension to exercise. The disease can be caused by old blood clots in the lungs and can lead to shortness of breath, chest pain and heart palpitations. The drug is also being developed to improve exercise ability in patients with pulmonary arterial hypertension. Pulmonary arteries carry blood from the heart to the lungs. In patients with PAH the arteries constrict, forcing the heart to work faster and blood pressure within the lungs to rise. If approved, the drug is expected to generate sales of $610 million, according to the average estimate of six analysts polled by Thomson Reuters. The primary safety concerns raised by the reviewers relate to bleeding, low blood pressure and possible impact on kidney function in some patients. The reviewers said the drug can cause birth defects and a risk-management program would need to be implemented. Reporting by Toni Clarke in Washington; Editing by John Wallace