There isn't a lot of information of over-the counter medications, as they generally are to old to fall under the requirements for thorough research. And when you look at supplements and herbal products, there often is never any research done. Sometimes your ob/gyn has that information available.

i think some do. I know that robitussin has been known to help women ttc because it thins the cervical mucus or something. So, I assumed it may counteract or at least make the bc less effective. Sorry, don't know exactly. Whenever in doubt use another form of bc, like condoms or something.

Hehe well its kind of an interesting situation, one that has since changed since I posted that.

My girlfriend and I had sex exactly one week ago (last friday). Her pill has been taken at the same time every morning for as long as she has been on it. She is religious about this.

Thursday (yesterday) she started to get a cough and began taking robitussin and sudafed. Today it got substantially worse that I took her into be seen. They took a throat culture and are thinking strep throat. They now have put her on an antibiotic which I am positive will interfere with the bcp, but thats not an issue since I will know in the future.

My *new* question is: does the reduced effectiveness these medications will have on the pill from here on forwad have serious implications for the act of last week? Basically, are there viable sperm still there from a week ago that might "get lucky" as a result of this weakening of the pill now?

Nope. Sperm can live (if they get past the cervix) for up to 5 days. And the antibiotics will def counteract. So, use a backup method during and a few days after she's done with those.

Thanks for your help

i had read that they can last as long as a week, and so of course my obsessive worrying mind went through the:

-she started taking robitussin on thursday, 6 days after.
- 6 days is (obviously) less than a week.
-now she is on antibiotics
-what if this medication caused her to ovulate either today or tomorrow, there could still possibly be sperm in there.

But... If I am reading you correctly, this would be a highly improbable scenario, correct?

Yep, they can only live for *up to* five days. They may not have lasted that long. And no otc or rx drugs can cause ovulation unless that is what the drug is intended for.