Sudden intolerance to antibiotics -- what's up with me?

January 25, 2024 8:53 AM

I have never had problems with antibiotics but in the last few years, when I take certain antibiotics I get terrible side effects. Has anyone experienced a shift like that?

YANAD or YANMD, I have a doctor, I have discussed it with her, but I am also curious about others' experiences.

Background: I have always had an easy time with antibiotics. Whenever I have needed to take them (which was never super often, but occasionally for, like, sinusitis or a UTI), it was no problem. Eleven years ago I even had to take strong antibiotics (clindomycin) for a prolonged period of time, about 2 months, following a serious medical issue that left me hospitalized for a week and a half. I never had any side effects -- not even gastrointestinal distress.

About four years ago, I stopped being able to tolerate antibiotics in many (not all) cases. The first time I noticed it happening was in Spring 2020, when I had Covid with the infamous bilateral pneumonia, and the doctor prescribed me a Z-pac for the pneumonia (which went fine) and then after that a course of Doxycycline, which I had taken before without problems, but which gave me such terrible side effects this time around that I could not take it for longer than 2 days. The side effects were wooziness, dizziness, and in general a kind of unwell body feeling that feels like a flu coming on.

Since then this same reaction happened a few times. What's interesting is, in some cases I tolerate a low dose fine, but when the dose goes higher, this effect happens (this has happened with Macrobid -- it's fine at 50 mg but not at 100 mg). It has happened with antibiotics that in the past I was able to tolerate fine at all doses.

Last night it happened again, this time with a suppository version of a drug I have taken before all these issues started orally, with no problem. In general I think of suppositories as less systemically affecting -- but within 10 minutes I felt flushed, tingly, and then that awful dizziness and unwellness set in; a few hours later it was compounded by thirst that I could not alleviate even though I kept drinking water. This morning it's mostly better but I am still not back to 100%.

I have noticed that this happened a couple of times with other non-antibiotic drugs, where a low dose is fine, but a higher dose creates awful side effects. The only time I had a reaction like that to a drug that seemed independent of the dose was to Diclofenac, which made me so woozy and sick that I was really scared something was truly wrong, and the only reason I didn't go to urgent care was because I felt like I was physically unable to get off the couch.

So, I am alarmed by this because what if a situation arises where I really need a high dose of antibiotics, and my body can't tolerate it? I am discussing this with my primary care physician, so no need to tell me to talk to my doctor, but I am curious if anyone has experienced a similar change in tolerance levels of antibiotics (and/or other drugs) that seems to be dose-dependent. I have wondered if maybe this is some weird effect of Covid, since the first time this happened was during my recovery from Covid, but obviously correlation is not causation.

I don't think it's an allergic reaction because I imagine that would be dose-independent. I do take some daily medications, but I have double and triple-checked for any counter-indicated interactions and found nothing.

Thanks for sharing any experiences -- I would welcome responses either from people who have had this happen to them, or from medical professionals who have had patients with similar experiences.

posted by virve to Health & Fitness (4 answers total)

Something like this happened to me, after a 40+ of unremarkable antibiotic use for tonsillitis and then, later, sinus infections. A year and a half ago, halfway through a course of amoxicillin for an entrenched sinus infection, I went to bed early feeling symptoms similar to what you describe. I woke up in the middle of the night, face and lips tingling, wheezing, with my throat, tongue, neck and face swollen almost beyond recognition. I managed to choke down a couple of extra-strength Reactine and go back to sleep. (Um...next time I'll call 911).

Long story short, after she finished reading me the riot act about not calling an ambulance, my PCP said that people can develop an intolerance to antibiotics over time, and it's likely that's what happened to me. It took 10 days of RX allergy pills to get me back to normal. Now, I do everything I can to avoid having to take an antibiotic – I've been referred to an allergist but the wait is years long.

It's scary –I hope you're able to get to the bottom of it!
posted by notquitejane at 9:39 AM on January 25

I went through a period like this (more like rashes and hives though) when I was under a tremendous amount of psychological stress.
posted by kathrynm at 10:15 AM on January 25 [1 favorite]

Firstly, not all antibiotics are the same, so reactions or lack thereof to one may not indicate the same course for another.
Secondly, it is possible to develop sensitivities to anything after multiple exposures, and antibiotics are known to have this happen, again, some more than others.
Luckily, for most common ailments, there are still alternative AB's that can be used, if the side-effects outweigh the need for the first choice med. This is where your PCP can help.
Lastly, it is possible that covid has had an effect on your system, but the research into all of the covid related conditions is still in its earliest stages and not likely to have been studied in enough depth to give you a usable answer.

I do hope you get it figured out, and don't run into the need for a serious dose of Ab for any reason.
posted by OHenryPacey at 10:56 AM on January 25

I am now sensitized to sulfa, amoxicillin/augmentin, minocycline, and by extension all -cycline antibiotics. My liver got very upset about the minocycline, with such impressive enzyme scores, the liver doc stayed late to see me. With this, I just felt really lethargic and not well, saw my doctor, got blood tests. With others, I felt ill and had a red speckled rash all over. Your immune system has a long memory, and can get reactive over time. I am now extremely cautious about taking antibiotics, because I feel like I need to have options for if I really, really need them.

Antibiotics are globally over-prescribed and abused. Huge quantities are used in the US beef and chicken industries, and I can't think this is good. As germs develop resistance to specific antibiotics, we have a looming crisis with TB and many other severe illnesses. Use antibiotics with care.
posted by theora55 at 11:27 AM on January 25