Q:  Is the Rash Stevens-Johnson Syndrome?

Dear Dr. Phelps,

I was recently diagnosed with Bipolar disorder and have been taking 25mg of Lamictal each day.

Initially I was really itchy, but that went away within days. Unfortunately, I then developed a blotchy red rash that was approximately the size of a quarter under my collarbone. It has not spread and is not very itchy, but I was told to stop the Lamictal for the time being.

Is there any way to tell definitively if the rash is THE rash? In other words, can a biopsy or similar test provide reliable results? Also, assuming the rash is benign, is it worth starting the Lamictal again at a lower dose?

I have been very happy with this drug otherwise and am very upset at the prospect of having to permanently discontinue it.

Thanks for your help.
 

Dear Ms. K' -- 
As you can probably understand, from a legal point of view I can't quite answer your question as I'd be telling you what to do.  But what I can do is give you information that might help you and your doctor decide what to do. This question, about lamotrigine (Lamictal) and rash risk, comes up all the time.  So I have prepared a summary of everything I've learned about this issue; see my webpage about "handling the rash".  It won't tell you what to do either, but it will show you that people have tried restarting again when in your position. 

The risk of THE rash (Stevens-Johnson Syndrome, SJS, is the main one) is variously quoted anywhere from 1 per 1,000 people taking the medication, to 1 per 3,000. You'll see some numbers which were designed to be a bit more precise on my website. But, my point here, these numbers are rather abstract. We humans are not good at turning numbers like those into some sense of risk that might help with a decision. Even with some additional numbers about people re-starting lamotrigine after getting a rash, you'll still have a hard time developing a sense of how risky such a step would be. I know, because I have been through this many times with patients considering a re-exposure to the medication. My results are too few to be relevant to your decision (if everybody did fine, this really wouldn't mean much; we need bigger samples of patients because what we're looking for is infrequent); but again, my point: even having been through this numerous times I myself still have difficulty helping my patients evaluate this risk. All we can do is talk about it and compare our alternatives and their  risks, and the risk or potential distress associated with continued symptoms, and then try to make the best decision possible. 

That's why this decision has to be made with your doctor. The good news, it sounds like, is that even at a low dose, the medication seemed to be doing something good. That's not uncommon. You'll be interested in the 5 mgs-to-start approach described on my webpage, as you wouldn't have to wait long even going by 5 mg a week to get back to where you were seeing benefit. Good luck with your decision. 

Dr. Phelps

Published April, 2006