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Swollen itchy palms and soles of foot after taking modafinil. Should I take an OTC antihistamine?

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Practicing since : 2009
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I had modafinil for 5 days, last dose 36 hours ago (yesterday morning) and last night developed a few areas of pressure / swelling / itching on palms and soles of feet, I believe from where they were vibrated by my motorcycle.

I've stopped the modafinil, but the slightly swollen palm (which is very itchy) hasn't really gotten better in 24 hours, and some other mild things showed up with it that havent' changed either -e.g. mild swelling / itching on my forearms where i rest them on the edge of a table. no rash on trunk, face, mouth, etc, but I'm still concerned I may have triggered some sort of progressive histamine reaction. Should I either just wait and see, take an OTC anti-histamine (benadryl) or go to the emergency room (in case this suggests early XXXXXXX Johnsons Syndrome)?
Fri, 8 Feb 2013 in Medicines and Side Effects
Answered by Dr. Sundar Gnanavel 12 minutes later
Thanks for writing to us.
As you rightly mentioned modafinil, a psychostimulant drug, used in various psychiatric and non-psychiatric conditions has been associated with hypersensitivity reactions. However, considering the symptoms you present with and the fact that you did well on the drug for 4 days before developing itchiness and there is no involvement of mucous membrane (mouth/lips/tongue), no symmetric skin rashes almost rule out any severe hypersensitivity reactions like XXXXXXX XXXXXXX syndrome. My opinion would be to try out anti-histaminergics and you should be fine.
Let me know if you have any more questions
Dr Sundar G
Above answer was peer-reviewed by
Follow-up: Swollen itchy palms and soles of foot after taking modafinil. Should I take an OTC antihistamine? 1 hour later
Thank you, Dr. XXXXXXX you answer is very helpful.

No mucus membrane involvement except dry sinuses / nose during this trial, although modafinil does seem to be quite "drying" and somewhat diuretic. I drank almost enough water to compensate. I recounted it was actually 8 days, but still not a long trial.

Only other minor things are itchy eyelids, and a few tiny itchy bumps on one flank, and top of my head, nothing symmetrical. I've taken a 25 mg generic benadryl (diphenhydramine) and will monitor.

I tend to react with large welts when bitten by mosquitoes, etc. In retrospect it seems my histamine system is rather sensitive.

Answered by Dr. Sundar Gnanavel 1 hour later
Hello XXXXXXX ......
You are right in guessing that your histaminergic system is rather sensitive as seen from your past history too! Continue your antihistaminergics and you should be fine soon. Wish you speedy recovery.
Dr Sundar
Above answer was peer-reviewed by
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