If you stop an antibiotic can you use it again?

Ask your doctor – - why?

Antibiotics often have a short shelf life. The expiration date should on the label. But you should never self medicate, and most definitely not with antibiotics. If you are prescribed the same antibiotic again and the supply you have hasn’t passed its “Discard if not used by…” date, then it’s perfectly sensible to save the cost of a new supply and use the ones you have.

The overuse of antibiotics just provides bacteria more and more opportunities to mutate into forms resistant to those drugs.

@ETpro Self medicate? I am on one antibiotic prescribed by the doctor and now he wants me to stop it and start a different one. I asked if this would make the current one redundant when I need it again in future.

@LornaLove Self medicating is deciding without a doctor’s advice that you need a particular medication—even one that was prescribed for you previously but not completely used up for the reason it was prescribed. If the confusion is about what the doctor wants you to do with the one you are stopping, call the doc’s office and ask.

@ETpro Clearly I have worded my question really badly.

I am on Amoxicillin. I like Amoxicillin since I am not allergic to it (as I am to many drugs). I have spoken to my doctor today and he wants to change me to another antibiotic. My question is thus.

If I stop Amoxicillin, will I create a resistance to that tablet due to suddenly stopping it? That would be sad. Why? Because I like Amoxicillin and should I in future need an antibiotic and go to the doctor and be told I need an antibiotic for any number of illnesses for e.g. pneumonia could I then tell him I can use Amoxicillin as I am not allergic to it. Or would stopping it cause that drug redundant in future for use by me?

Yes, you can. It takes awhile to build up antibiotic immunity.

@Mariah Thank you!

Aha. Well glad you got an answer to what you meant to ask. :-)

Wishing you a speedy recovery.

Yes. I believe you can.

Your doctor probably got you to change antibiotics because the other one was ineffective in so far as the complaint you are trying to treat is concerned, doesn’t mean it will not work for another complaint. Check the expiry date for the antibiotics on the bottle and do not use beyond that.

While the leftover, unused antibiotics might still have potency you need to take a full course of antibiotics; not only for them to be effective against whatever bacteria you are taking them for, but if you don’t take a full course of antibiotics and kill all the bacteria, all you are doing is killing the weakest ones and leaving the stronger ones alive. That endangers us all. You are helping to create strains of kind of “super bacteria,” you are helping to create extra strong bacteria that can become resistant to antibiotics. Then we’re all fucked, you know? Then the antibiotics in our arsenal become more and more useless and ineffective.

So if your doctor has changed your prescription and put you on different antibiotics please dispose of the others properly. Please don’t save them for some other time when you think you might need them.

You can but, and big but, antibiotics need to be taken in a large enough dose and enough days that it effectively gets rid of the bacteria. So, if you take penacillin for instance for 4 days for strep throat, but you need to take it for 7 to make sure you did not miss killing off any of the bad bacteria, taking it just for 4 will get rid of your symtoms for a few days, but after stopping the med you will be sick again in a few days, because the bacterias leftover will just divide and multiply and it’s like you never took any medication in the first place.

The one good thing about having a stash of the meds, is if you get sick with something in the future and your doctor prescribes that same med, you can start taking it right away and pick up the prescription when it is more convenient, instead of racing to the drug store. However, I wouldn’t keep them more than a year. It’s important the pills haven’t lost their efficacy.

@JLeslie I was thinking the same thing. So have decided to continue just today and tomorrow left. Then phone him to start the new one. I’m not sure why everyone thought I was keeping the pills? The point was that I did not want to become resistant to this type of antibiotic. Even if I did keep them it would be strange as there is not a full course. I would just get a new course for whatever reason they were prescribed for at that time.

@LornaLove I see no problem with you switching right away if he changed your meds to treat the same infection you have been treating. You asked two separate questions really. Whether to switch right away, which I failed to address, hut I do think is fone, and whether to keep the leftovers of the drugs.

Why did your doctor switch you?

Don’t worry about the bacteria becoming resitant in this case, what is important is getting better. I assume the doc switched you because this med is not working, which means the bacteria you have is resistant, no point in continuing the drug if that is the case.

So, a quick note that I didn’t see properly answered, you being resistant is not the problem, but the bug currently attacking your system. Kind of depends on how you define ‘you’, since it will probably continue to kill beneficial bacteria in your system which are quite important to your healthy existence, but your human cells are already mostly resistant, while it’s called an ‘antibiotic’, it’s better described as an antibacterial, it just kills bacteria (to get very specific, it’s a bacteriolytic antibiotic, but same thing. Very very specifically, it attacks bacterial cell walls, which you do not have). As long as you have killed said bug, you could keep taking the drug forever and it wouldn’t really make a difference. Well, probably wouldn’t be great since you’d become a superbug incubator and it would kill off your good bacteria, but the effects on your human cells would be negligible.

So, if you get a new infection in the future, a truly new infection that wasn’t just lying dormant (which is the case for most things you’d take Amoxicillin for), it doesn’t matter that you’ve taken Amoxicillin before; this new infection is new, and if it’s resistant to the drug it will have been because of a different source making it resistant and whether you have taken it or not before is immaterial.

Now, if you stop it now and your illness isn’t dead, that will indeed lead to resistance, but that’s just the same illness evolving, it’s not a new infection, and that’s what leads to you passing the newly resistant bug to more people. But it’s different then being able to ‘use it later’. And it won’t take long to come back, either. However, your doctor should understand that, so if you trust his judgement you should be okay with changing things as he directed. Either way, any new infection that occurs down the line will still be affected by Amoxicillin regardless of what you do with this infection.