I'm taking doxycycline, and I have an ache in my upper back. According to this site
, I should "call [my] doctor at once". But, according to this other site
, muscle aches/soreness aren't in the list of things that I should worry about.
When I've called my doctor during off hours in the past, to leave a message, there's a message saying "if this is an emergency, press 1 now", so I can probably page her and/or reach her cell, but I don't want to bother her on a holiday if there isn't at least some chance it's serious.
Last time I had a side effect while on an antibiotic, I got this answer
when I asked about here, and it turned out to be a severe reaction which left me in the hospital for a week. That's probably coloring my view of things, causing me to worry when any normal person would shrug off my current symptoms, which sound really minor.