21,149 members16,754 posts

Warning about Methotrexate taken with Amoxicillin

Hello everyone. I just wanted to share some information with everyone that I learned the hard way. Methotrexate and high doses of Amoxicillin should not be taken together because the Amoxicillin can increase the side effects of the Methotrexate. My pharmacist should have alerted me to the interaction, but did not. You can look up online to see drug interactions and it shows a severe warning about taking the two together. I didn't know this until it was too late.

I had been taking methotrexate for about 2 months and my body was finally starting to adjust to it and my side effects were getting much better. However, I had to have 2 abscessed teeth (thank you Sjogren's) pulled. My dentist put me on 500mgs of Amoxicillin 4 times a day for 10 days before he could pull it.

Out of nowhere I got so weak that I couldn't walk without assistance (I'm 42) and if I didn't have help, I would collapse to the floor. Once on the floor, I could not get up on my own. I literally had to be pulled up off the floor and my husband would have to support my weight to guide me to the restroom. I felt like I was dying. I couldn't eat and had no desire to and could do nothing but stay in the bed. I went from 140 pounds to 133 in 5 days.

My husband took my methotrexate away from me like someone would confiscate an illegal drug they found in their partner's possession. He said the Methotrexate was killing me and he refused to let me take it anymore. In a couple of days I was better.

I just wanted to share this with the community because too often our doctors, dentists, and pharmacists give us medication that can interact with other meds we are taking, even though they have our chart of the meds we take and should know about the interactions.

My husband was quick to blame the Methotrexate, but it was the "innocent" Amoxicillin that caused the reaction when taken with the Methotrexate. I read and have learned that if a person takes Methotrexate and is prescribed Amoxicillin, they should skip their dose of Methotrexate until they finish their Amoxicillin to avoid a severe interaction.

I hope this helps someone and prevents the same thing from happening to someone else.

Have a good day everyone..


P.S. I eventually got my methotrexate back and have not experienced anymore problems while taking it.

6 Replies

YIKES 😧....glad you figured this out! Vvvvvv interesting! We do have to be alert to these meds interactions! VVVVVVV glad you've posted & glad you're over that 👏👏👏👏

🍀🍀🍀🍀 coco

1 like

Once again, on health unlocked, despite your own acute suffering, you are thinking of others, and sharing your horrendous experience, in the hope no one else will suffer as you did.

It is people like yourself, that make this site invaluable to many of us here.

Thank you for sharing and caring.

I hope you stay as well as possible for a long time. And, yes! That sjogrens has a lot to answer for!!


It's very good of you to share this with others. Very glad to hear you are back on track again.

I am though amazed that you were not warned. When I started MTX about 1.5 years ago I was given a 3 page A4 doc on the yahs and nays when taking MTX. The Pharmacist was very switched on indeed.

The other thing I have learned since becoming unwell in 2011 is every time a new drug is added to my cocktail list I always ask about when to take it and interactions. The Rheumatologist told me about the antibiotics and said that basically it increases the bio availability of the MTX and that is why its a big no no to mix the two.


When I went on methotrexate over ten years ago I was given a guide sheet listing the do,s and don't and advice on dentist the advice was if having teeth pulled you should consult gp to stop methotrexate and start anti biotic because your immune system will be low and unable

To fight infection .

Late December 2012 I was to have to broken teeth removed visited gp to be told advice had changed only antibiotics in ad vent off infection had my teeth out on the last days off December so got infection and suffered he'll over the holidy had to wait four days to see

Emergency dentist who cleaned out the gums and packed and dressed them gave me a antibiotic that didn't work went to a&e was kept in for four days on iv antibiotics was unwell for some time so iff on methatrexate and need any dental work be very careful

Incidently my reumatoligist stopped the methotrexate last December after ten years

Because it wasn't doing any good I had told her that many times .

1 like

I wasn't given a list of which drugs interact but I was told by my Rheumy nurse when being shown how to do the injections that I couldn't take certain antibiotics and especially not amoxicillin. I also got told to be careful with painkillers including even paracetamol as it increases the effect on the liver. She advised that if I'm taking anything beyond the odd headache tablet I should check with them first. Having said that thinking about it when I was taking thentablets I wasn't told anything which is quite frightening really!


Thanks for sharing that !


You may also like...