Ranexa is the first drug approved to treat chronic angina in more than 10 years.
The precise way Ranexa works isn't fully understood, though several of its pharmacological activities have been described, states an FDA news release.
Because Ranexa affects electrical conduction in the heart, the drug should only be used by patients who haven't responded to other angina drugs, states the FDA.
Chronic angina is characterized by usually predictable episodes of chest pain, pressure, or discomfort that occur during exertion because the heart muscle is not getting enough oxygen.
In 2003, 6.5 million people in the U.S. had some form of angina due to insufficient blood flow to the heart muscle, according to the American Heart Association. Though many of those patients respond to other treatments, including surgery and other approved drugs, some still have angina despite such treatments.
Ranexa was studied in patients with chronic angina who still had symptoms despite being treated with other angina drugs. Two clinical trials were conducted.
In the first, 565 patients who were experiencing about 4.5 episodes of angina a week while taking angina medication were randomly assigned to take either Ranexa or a placebo for six weeks. Patients receiving Ranexa had a reduction in angina of about one episode per week, compared with those in the placebo group.
In the second study, 823 patients taking angina medication were randomly assigned to take either Ranexa or a placebo and were followed for 12 weeks using a formal exercise treadmill test. Patients in the Ranexa group had an average exercise improvement similar to that seen with the other angina therapies.
In both studies, Ranexa appeared to be less effective in women than in men.
Ranexa's manufacturer is CV Therapeutics Inc. of Palo Alto, Calif.