According to a preliminary study, combining daily 100 milligram doses doxycycline and interferon therapy reduced the number of brain lesions by a quarter in a group of 15 relapsing patients.
Fewer lesions were visible using MRI scans, the study said, and patients also had reduced scores on a scale designed to assess disability.
Only one patient in the study group relapsed and adverse effects caused by the medication were mild.
The study is due to be printed in the February 2008 edition of the Archives of Neurology.
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