40-Year-Old Gout Drug Shows Promise Against Angina
MONDAY June 7, 2010 -- A new British study suggests that a standard treatment for gout, already in use for four decades, could be an effective and less expensive alternative to conventional drugs targeting chronic stable angina.
Following work with 65 heart disease patients between the ages of 18 and 85, the research team noted that six weeks of high doses (600 milligrams per day) of the gout drug allopurinol appeared to curtail the activity of a particular enzyme called xanthine oxidase, and in so doing cut back on the amount of energy the heart needs to exert whenever it beats.
Exercise tests further revealed that allopurinol enabled the angina patients to get more oxygen to heart tissue plagued by blood and oxygen deprivation due to the arterial narrowing that characterizes coronary heart disease. Without treatment, this oxygen supply issue -- called ischaemia -- often leads to the onset of severe chest pain, sometimes as often as once a week.
The findings were published online June 8 in The Lancet.
"Allopurinol is inexpensive compared with some other antianginal drugs such as ranolazine and ivabradine, and has a favourable long-term safety record for the treatment of gout," the study authors, led by Allan D. Struthers of the University of Dundee, said in a news release.
Referring to standard angina treatment, Struthers said "allopurinol is better tolerated because it does not reduce blood pressure or heart rate, and does not cause many side effects, such as headaches and tiredness, that occur frequently with nitrates and beta-blockers."
The study authors concluded that "on the basis of our results, allopurinol is a useful anti-ischaemic treatment option in patients with angina that has the advantage of being inexpensive, well tolerated and safe in the long term."
"The precise place of allopurinol in the management of angina pectoris now needs to be explored further," the researchers added. "But this drug might be especially appealing for use in developing countries where coronary artery disease is rapidly increasing in frequency and where access to expensive drugs or invasive treatments (angioplasty and bypass surgery) is often restricted."
Dr. Kirk Garratt, clinical director of interventional cardiovascular research at Lenox Hill Hospital in New York City, said the "mechanism of angina relief with allopurinol is mysterious, but the clinical findings are supported by earlier work. The fact that this is a low cost drug with few side effects and a great safety profile will drive interest."
"The few patients that dropped out of the study seemed to have worse baseline angina and were taking more daily nitroglycerin pills," he said. "This makes me wonder if allopurinol will be better suited for patients with moderate, rather than severe, chest pains.
"This was a very small study, but the results were impressive. If allopurinol still had patent protection, we'd likely see a large-scale trial. But that won't happen now that it's a generic drug, so clinicians must decide if this small trial is convincing enough," he added.