Warfarin may ease chronic cluster headaches
Last Updated: 2011-04-22 17:27:13 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Low-intensity anticoagulation with warfarin appeared to have a beneficial effect on chronic cluster headache in a recent crossover study.
There have been isolated case reports of anticoagulation for this purpose, but no randomized trials until now, says Dr. Sameh M. Hakim of Ain Shams University in Cairo in a March 11th online paper in Headache.
In a pilot study, Dr. Hakim randomized 34 patients with refractory chronic cluster headache to receive warfarin or placebo for 12 weeks. After a 2-week washout period, patients crossed over to the other arm for a further 12 weeks. Warfarin was titrated to achieve an international normalized ratio (INR) of 1.5 to 1.9.
Seventeen patients (50%) had remission for at least 4 weeks during the warfarin phase, compared to only four patients (11.8%) during the placebo phase (p=0.004).
The frequency, duration, and intensity of cluster attacks were all significantly lower during treatment with warfarin, as was their impact on quality of life.
There was no significant difference in the mean frequency of cluster attacks during the washout periods. But the mean duration and intensity of attacks were significantly lower during the warfarin washout period.
It's unclear what the underlying mechanism may be, says Dr. Hakim, but it's unlikely to involve any direct anti-inflammatory action.
"An apparently more plausible hypothesis may be related to vitamin K," he suggests, "which seems to exert biologically relevant actions on dendritic and neuronal metabolism."
"Larger randomized controlled studies are required to identify the optimal level and duration of anticoagulation, and the potential risks of such an intervention," Dr. Hakim concludes.
SOURCE:http://bit.ly/fwSolS
Headache 2011.
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