Antibiotic May Slow Osteoarthritis
Researchers Say Doxycycline May Protect Joints From Damage
June 29, 2005 -- A common antibiotic may slow the progression of
A new study shows that treatment with the antibiotic doxycycline slowed the
deterioration of joint tissue in women with osteoarthritis of the knee.
Doxycycline is used to treat a variety of bacterial infections. Previous lab
tests with animal and human tissue showed that doxycycline may help preserve
joint tissue, say the researchers. They add that this is the first major study
of the antibiotic as a potential treatment for osteoarthritis.
Osteoarthritis is a common form of arthritis that causes progressive
destruction of the cartilage that cushions the joints. Common symptoms are
joint pain and stiffness. When severe, osteoarthritis can cause loss of
movement in the affected joint.
Antibiotic for Osteoarthritis?
In the study, which appears in the July issue of Arthritis &
Rheumatism, researchers compared the effects of doxycycline to a placebo
in about 400 obese women with knee osteoarthritis. Specifically, they measured
the impact of treatment on the joint space in the affected knee. More joint
space indicates a loss of cartilage and progression of the disease.
The women were randomly divided into two groups and received either 100
milligrams of the antibiotic twice daily or a placebo for up to two and a half
After 16 months of treatment, the study showed that the average loss of
joint space in the diseased knee was 40% less among those who took doxycycline
vs. the placebo. After two and a half years, the average loss among the
antibiotic group was 33% less.
Although these results suggest the antibiotic slowed the progression of the
osteoarthritis, researchers say it did not reduce the severity of joint pain
reported by the participants.
However, researchers say the average level of pain was low in both groups,
which may have provided limited opportunity for the treatment to show an effect
But doxycycline was associated with a reduction in the number of times the
patients reported a 20% or more increase in knee pain.
Researchers say the study suggests that the antibiotic may provide benefits
in the treatment of osteoarthritis but more studies will be needed to confirm