Bad allergy, cold, or Doxycycline

I am taking 400mg/day of Doxycycline to treat my Lyme Disease.  While I normally have some post-nasal drip due to various allergies, the past few weeks have been really bad on the 'gunk factor'.  On top of that, I have a sore throat a good deal of the time and I sometimes get moderately congested and sneezy.  Last night I thought that I had the beginnings of a cold.  This morning I feel a little better as far as the sneezing and congestion go.

Also, in the last few weeks I have been getting headaches while I am sleeping.  I usually wake up an hour or so before the alarm goes off.  Lately, I've woken to a moderate headache.  I've been taking acetaminophen and then going back to bed to sleep until the alarm goes off.  The headache has been either less annoying or gone when I wake.


I have an appointment with my doctor on Tuesday for a B-12 injection.  I plan on mentioning these annoyances to him at that time.  I have been on the Doxycycline for just over two weeks now.  While I didn't expect to see any improvement to my Lyme symptoms yet, I wasn't expecting these particular side effects.  It's not enough to want me to give up the antibiotic.  I just want to make sure that these are possible side effects and not something else going on.