Warfarin and oral antibiotic therapy

[new2aps]

I take warfarin for APS - target INR 2.5 - 3.5. I have 2 non-healing insect bites on my big toe. I will probably need an antibiotic. I was wondering if anyone has experience with antibiotic therapy while on warfarin and which ones you believe are safest to take orally. Thank you!

[Ray46]

Safest assumption is that all antibiotics will affect your INR. By how much and which ones are better or worse will likely be personal to you, so only way to find out is to try.

I've actually had a doctor spend several minutes going round in circles on a prescribing flow chart (on his computer) before throwing his hands in the air and shouting "but I've got to give him something". The problem was antibiotics for an infected surgical wound. Can't remember what I got in the end, but they were evil in all sorts of ways, as antibiotics are. Whatever was in the wound was more evil though, and it needed sorting. The scar is still a mess today years later, but it's on my back so I don't have to look at it.

[new2aps in reply to Ray46]

Thank you Ray for taling the time to respond. Glad they cleared up your infection though!

[KellyInTexas Administrator]

Hello!

Sorry to hear about your toe.

I believe Ray has said exactly what I would.

I cave compared notes before with another APS friend on warfarin when needing antibiotics, and what will raise her INR, will not raise mine, strangely.

With that said, generally the there is enough data that there are trends that can be relied on.

The best thing to do is definitely go to your doctor. ( APS patients need to be mindful, but not overly anxious) that a very small percentage of us can develop ulcers in our lower extremities due to compromised circulation/ oxygen. Best to get ahead of any problems. And any infection.

Your doctor will be able to guide you with regard to INR / drug interactions. You will need to monitor the inr very closely no matter what.

Best of luck with healing.

[GillyA]

No wounds, but several infections requiring antibiotics and other drugs in the last 6 months. The dr will need to balance out the right antibiotic for the infection and the potential impact on INR. You’ll then have to monitor INR closely and adjust warfarin dose as necessary.

All a bit of a pain (especially if you don’t self test) but actually I found it less of a drama than expected. In my most recent heme visit I had a list of kidney infection, malaria (twice), Covid and UTI (oh and an epileptic seizure for good measure). Lowest INR 1.8, highest 3.6. Heme was astonished I’d somehow got through all this in 6 months with no INR crisis 😎

[nossib in reply to GillyA]

I was the same, with the same readings after having a succession of antibiotics for a leaking venous leg ulcer. Also, experienced the same situation as hihannula.

[GinaD]

Topical antibiotics have less effect on INR, but INR maintenance can be done on orals-you just need to check often and adjust accordingly. Do take care and replenish of your gut biome with high fiber foods and probiotics during and after treatment. Yogurt, --either dairy or non dairy help. As well as nuts.

[bevjane74]

Hi, I've been on anti biotics before I'd just advise going for an INR check while on them and they'll probably ask you to come back when you're finished them to keep an eye on your reading and readjust your warfarin if needed, to be honest any anti biotics I've been on haven't had too much of an impact on my INR but that would I expect to be different for each person

[hihannula]

I have PAD, with 70% stenosis in my left leg. 6 weeks ago, I injured my lower leg quite badly, and developed an incredibly painful soft tissue infection, called cellulitis. It took many stitches, and 3 rounds of 3 different antibiotics to finally kill the bacteria. The first two antibiotics I took caused severe diarrhea, and a high spike in my INR, as high as 5.9.The 2 drugs were: Teva-Cephalexin for 5 days, and then tried Clindamycin for 8 days. Neither of those antibiotics worked for me. The last antibiotic I took was called Amoxi-Clav, with no diarrhea, nor did it increase in my INR, and it finally worked. Should have went on that one in the 1st place. Hope this helps. All the best. P.S. Everyone is so different with how they react to drugs. Just make sure you get blood draws every 3-4 days, like I did. The thrombosis unit kept careful attention on me, while on all of these antibiotics.

[terrim]

All antibiotics affect your INR the only thing you can do is have a reading before and within three days of finishing the course so your dose can be adjusted accordingly. Some antibiotics send my INR soaring while others bring it down

[nossib]

Very important to get antibiotics and an antihistamine for mosquito bites. I was bitten severely by mosquitoes several years ago, incurring cellulitis and then a breakdown of my lymphatic system, causing severe & permanent lymphodema.

Now, have had my first venous ulcer and been on a succession of antibiotics the last 4 months but it was more importnt to be on them...my INR was 3 .5 last week and they have lowered my dose, to be checked again next week.

I had a pulmonary embolism a few years ago, a very frightening experience and on warfarin now for life.

[MaryF Administrator]

Hi, you doctor will help you with this, however I think with any antibiotic/virus/infection - you will need to keep a close eye on your INR during that time as things settle down for you. MaryF