Doxycycline allergy permanent?

Hello,
I have had asthma since infancy, now that I'm 65 it has pretty much left me, except for a yearly bad chest cold for which I'm always prescribed antibiotics once it settles in my chest and I can no longer move air.    Unfortunately, at this start of a 4 day holiday weekend, I have been struggling/fighting my annual illness for over 10 days, hoping to not have to rely on taking drugs, but see that as of today I shall need them in order to get well.   This is my ?:  I have a full bottle of Doxycline which was prescribed for last year's bronchitis.  I took a couple of the pills then and got a strange itchy feeling in the back of my throat, so the doc prescribed another drug.  I'm just wondering, is there a possibility that I can take this drug at the current time w/o a reaction?  What prompts this question is that a couple of years ago I got a terrible reaction from eating shellfish, but then a few months later tried it again (epipen in hand) and I was symptom free.  Thanks so much in advance for your time at the holidays, and Happy New Year!

[Dr. Kokil Mathur]

Hi
Welcome to the MedHelp forum!
Antibiotic bottles once opened should not be used if kept like that for over a month, even if they are within the expiry period. If you have taken Doxycycline in past without any problem, then maybe you can still tolerate it without any reaction. As a word of caution, allergy can develop to a particular thing even after prolonged use. So keep an anti allergic beside you and buy a fresh bottle and try. Hope this helps. Take care!

A VERY HAPPY AND DISEASE FREE NEW YEAR TO YOU TOO!