ANTIBIOTIC CLARITHROMYCIN (BIAXIN) CAN HAVE DEADLY INTERACTION WITH ANTI-GOUT DRUG COLCHICINE

August 29, 2005

Using the antibiotic clarithromycin (BIAXIN, BIAXIN XL) in combination with the gout drug colchicine increases the risk of death because of colchicine toxicity, a recent stidy shows. Research staff from the University of Hong Kong published their findings about this dangerous interaction in the August issue of the journal Clinical Infectious Diseases., The potential for harm is especially high in patients with kidney problems.

Both clarithromycin and colchicine are very popular drugs in the U.S.   In 2004, the total number of clarithromycin prescriptions exceeded five million.  More than 2.3 million prescriptions for colchicine were dispensed during the same year.  Colchicine is also available in combination with another anti-gout medication called probenecid.  This combination is sold as COL-PROBENECID.

Colchicine toxicity manifests itself as abdominal pain, vomiting, diarrhea, and fever.  It can damage the bone marrow’s ability to make all types of blood cells, technically referred to as pancytopenia.  This decrease in blood cells causes severe anemia and seriously low numbers of white blood cells.  White blood cells are important for fighting infection.

The researchers identified 116 patients admitted to their hospital between February 1997 and September 2004 who had been prescribed both colchicine and clarithromycin.  They compared the clinical outcomes of patients who took the two drugs simultaneously and those who were prescribed the drugs sequentially, having had a prescription for one drug started only after the course of therapy with the other drug had been completed.

In the 88 patients who received the two drugs together, nine (10.2 percent), died.  Only one (3.6 percent) of the 28 patients who received the two drugs sequentially died.  The risk of death was greatest in those with kidney problems and with the loss of the bone marrow’s ability to make blood cells.

This drug interaction appears to occur because clarithromycin simultaneously increases the amount of colchicine that is absorbed into the blood stream and decreases its breakdown by the liver, leading to the accumulation of dangerous amounts of colchicine in the blood.  The accumulation of colchicine is even greater in patients with kidney problems because their ability to excrete the drug in the urine is decreased.

The study’s authors’ straightforward and sound advice is that colchicine and clarithromycin not be taken together. They also recommend that for patients that need colchicine and require an antibiotic similar to clarithromycin, azithromycin (ZITHROMAX) may be substituted.   Azithromycin does not increase the absorption of colchicine or inhibit its breakdown by the liver.    

What You Can Do

You should contact your physician immediately if you are taking colchicine and clarithromycin together.