I am probably predisposed to the condition.....it tends to hit fair-skinned women in their 30's with Celtic ancestry. That's me.
There is no cure for rosacea; it's a chronic condition that is managed, sometimes going into "remission" and then flaring up.
One of the treatments for rosacea consists of taking Doxycycline, an antibiotic, for about a month or two depending on how quickly symptoms subside. Doctors aren't quite sure why the antibiotic works for rosacea, because rosacea isn't exactly an infection.
Anyway, now that I've bored everyone with my medical conditions, the point is that I had some Doxycycline in my medicine cabinet from the previous time I had taken it a couple of years ago. My rosacea was acting up and I decided to just take it because I didn't have time to get to the dermatologist and just figured they were going to tell me to take Doxycycline anyway.
I noticed it was expired, but then recalled a pharmacologist I once knew saying that most medicines are still effective way past the expiration date. I figured the worst thing that could happen would be that I would take it and it wouldn't work in which case I would have to go to the doctor anyway.
A curious mind is an infernal thing. It never knows when to stop. It's always asking "Why?". It's always wondering how things work. It's like a five-year-old child pestering their parent with a thousand questions a day, unsatisfied, always wanting more, more, more. More answers. More explanations. More understanding of generally obscure, not-very-useful facts.
Unfortunately, I have one of those question-generating-machines in my skull driving me to look things up. Curious about why medicines expire, or what could happen from taking expired medicines I used some free time to look it up.
This is what I found:
Store doxycycline at room temperature away from moisture and heat. Throw away any unused medicine after the expiration date on the label has passed. Using expired doxycycline can cause damage to your kidneys.
What??? Kidney Damage???
In a panic, I tried to find more information.
Everywhere I looked on general, medical, non-obscure sites I found this dire warning about doxycycline and the words "renal failure" used in conjunction with expired doxycycline and tetracycline antibiotics.
OK. I had taken 3 days worth. How much trouble was I really in? Should I let my husband know so that he could start planning my funeral? How quickly was I going to die? What symptoms should I look for?
So off I went through the inter-webs trying to find out more information, more details, more understanding of why this stuff is so bad for kidneys.
And what did I find?
The first clue came from the wiki article on doxycycline.
In the case of doxycycline, the absence of an hydroxyl group in C-6 prevents the formation of the nephrotoxic compound.
Oh. OK. So maybe I wasn't going to die after all.
Now I was very curious. Which was it...Deadly Toxin, or Meh?
Eventually I came across the topic in this forum which seems to be associated with Rutgers University.
The forum administrator, while trying to answer a poster with the same question I had:
I tried to find the data behind the statement that "expired doxycycline can cause a dangerous syndrome resulting in damage to the kidneys" (Source (http://www.drugs.com/doxycycline.html)). I was unable to find a published study on the subject although there are many outrageous warnings of the dangers of expired tetracycline or doxycycline all over internet. Let me continue looking but this is making me very suspicious.
I followed the thread which I won't entirely repost. He listed some information and basically said that there have been no studies about expired doxycycline and the information he was able to find was based on some case studies over 40 years old.
He finished the conversation with:
I was quite surprised to find all these strong warnings all over internet, including statements that taking expired tetracycline and doxycycline can kill people. That is one of the problems with internet. All these people are posting and reposting information without critically evaluating it. Even reputable sites are reposting the information.
It turns out that tetracylines can degrade into a toxic substance, but so far there haven't been any concrete, documented examples of expired-doxycycline-caused renal failure.
I hate when I mentally bump up against this. It always shakes me up a little when I come across these situations.....situations in which normally reputable people and organizations turn out to not know what the hell they are talking about.
Received wisdom from a perceived, authoritative source can become so powerful that no one questions it. When we have a source that we have previously experienced as being smart, knowledgeable and useful, it is easy to assume that it will always be so.
It's uncomfortable when we realize it's not.
Anyway....turns out that I probably won't die... at least not from expired doxycycline.....but at the same time I don't think that I will take any more of it.
You know...just in case.