How much is efficacy of pill decreased?

iVillage Member
Registered: 03-05-2004
How much is efficacy of pill decreased?
4
Fri, 06-04-2004 - 4:52pm
Okay, so I went to my dermatologist yesterday who prescribed me an antibiotic for my acne. I had concerns because I had always heard that antibiotics decrease the effectiveness of the pill, so becauase I am on OTC-lo and not wanting children at this point in my life, I asked him about this. He said there were no solid studies that showed that antibiotics had this effect, and that all of the things I had heard before were just rumors or stories not reporting the entire picture. But, he encouraged me to talk to my gynecologist anyway, which I did today. He told me that there was a chance that antibiotics could decrease the effectiveness of the pill, and I should consider using a backup method. This was incredibly frustrating, because I may end up taking this antibiotic for a while (for now at least 2 months), and the whole reason I went on BCP in the first place was to not have to rely solely on condoms (even though my fiance and I normally use them in addition to the pills). I tend to be a worrier, so using a couple of different methods always eases my worries. Anyhow, after all of this rambling, my question is...just how much is the effectiveness of the pill decreased? What exactly does this mean? Does it mean I am more likely to ovulate? Or does it mean I probably will ovulate? This is all very confusing to me. Any advice, comments, or suggestions would be greatly appreciated!

SARA

 

iVillage Member
Registered: 12-30-2003
Fri, 06-04-2004 - 11:02pm
Hi luvbert, welcome back!

With one exception no one can say which women will be affected by which antibiotic so there is no way to say if the effectiveness of OCs will be reduced (or if it is by how much) for you on a particular antibiotic. That is why this board recommends using back-up during the entire course of the AB and for at least 7 days after the final dose. Sorry, there is no way to be more specific. Which antibiotic will you be taking?

If you want to use a method in addition to OCs and condoms while you are taking your ABs you might want to consider a diaphragm or cervical cap or the contraceptive sponge. Diaphragms and caps need to be fitted by a medical practitioner the sponge (Protectaid or Today) can be purchased at some pharmacies or over the Internet. If you are interested in a diaphragm or cap there is more info. in the FAQs on the Board webpage at http://pages.ivillage.com/cl-judie_rae/id1.html If you have questions about diaphragms or caps please ask.

Good luck

      Jill

    

iVillage Member
Registered: 03-31-2004
Sat, 06-05-2004 - 1:45am
You'e not alone. My family doctor prescribed an antibiotic for bronchitis. When I asked if it would interfere with my Alesse he flat out said no. He said they've come a long way in their understanding of the relationship between antibiotics and oral contraceptives. He said most of the modern, widely prescribed antibiotics can be taken at the same time as oral contraceptives with no problem. Like you I was surprised and a bit leary. But he's a good doctor who keeps up with the latest research and findings. Hopefully in the near future we'll get a definitive answer on the subject.
iVillage Member
Registered: 02-11-2004
Mon, 06-07-2004 - 11:37am
I am in the same boat. back on 5/28 my new doc put me on bactrim for a sinus infection. I made it crystal clear to this guy that i was on OTC-lo. He said nothing about the interaction and then on 6/1 i had ALOT of cm wiht a small clump that was cloudy (tmi..sorry)the CM is definatly unusual for me...and i called my pharmacy and they said that all AB interact with OC. now my GYN says that i prob. O'd on 6/1 and probably conceived on 6/2 and the last time BF and I had sex was 5/31 and his little guys can live for up to 4 days...so i'm thinking since that my fertile days were the days i was on the AB, that the chances that i'm PG are there. And now 1 week from the last time we did it..i'm experiencing alot of cramping in my low stomach...but i havent gotten any cramps since i've been on OTC-lo and peeing alot and really sore boobs and darker aereolas. would signs show up this soon?? The anxiety is killing me and i really wanna take a HPT, but dunno if it would show up just yet. AF is not due for another week ...please help!!! =)
iVillage Member
Registered: 04-19-2004
Mon, 06-07-2004 - 5:52pm
In about 4 days you should take a pregnancy test to be sure, but, with darkening areolas I'd say there's a solid chance you're pregnant. Of all the side affects of the pill (nausea, breast tenderness, frequency of urination, cramping) that are similar to pregancy, the dark areolas seem to be a dead givaway. A pregnancy test won't be accurate sooner than 10 days after fertilization. If you have spotting in the next few days that could be a sign of implantation. Best of luck.

Oh, and to the woman whose doctor said that no antibiotics reduce pill effectiveness, that's just wrong. There hasn't been enough conclusive research to determine which antibiotics and which pill formulations interact badly, but it's widely known that certain antibiotics affect the way your liver processes the hormones in your pills. this means there's a solid chance of ovulation during the antibiotic course. those drugs are: tetracyclines (e.g. tetracyline, minocycline and doxycycline), penicillins (e.g. penicillin, ampicillin and amoxicillin), and trimethoprim. Both of my doctor's offices tell patients to use backup when on any antibiotic.

If you're anxious about using condoms as your sole protective method, you could also chart your fertility signs to be aware if your pills aren't protecting you and to know which days you shouldn't have intercourse should you become fertile.

http://www.plannedparenthood.org/bc/WaysToChart.html