Can You Take Birth Control Pills And Macrobid Together?

Hi Stressed and thanks for writing to us. 

Femynor is a combination birth control tablet, containing norgestimate and ethinyl estradiol. It is available by several other names including, Sprintec, Estarylla, Mili, Mono-linyah, Previfem, and Ortho-cyclen.

Antibiotics And Birth Control

Now, on to your question, it’s actually quite a debated topic whether or not antibiotics affect oral birth control pills. Much of the evidence leans towards the majority of antibiotics not making birth control pills less effective when used together.

Now, there is a good amount of evidence that a few antibiotics DO reduce birth control levels (i.e. hormone levels), and these antibiotics include rifampin and rifabutin. These antibiotics are uncommonly used however. They interact with birth control pills by causing the liver to produce additional metabolizing enzymes, which can cause increased metabolism of many different drugs, including birth control pills. Nitrofurantoin is not related to these drugs.

Other antibiotics might reduce birth control levels, but there is less evidence. These include penicillins and tetracyclines; drugs that seem to kill off a lot of the good bacteria in your gut, which may lead to reduced levels of the estrogen component of birth control.

Again, the majority of studies that have looked at birth control failures have not found a strong association when taking antibiotics. Birth control failures do happen, but they don’t seem to occur at rates greater than women not taking antibiotics. 

Nitrofurantoin And Birth Control

Specifically talking about your medication, nitrofurantoin is not known to have a large impact on the good bacteria in the GI tract.

There are not a large number of case reports of birth control failure while taking nitrofurantoin and a potential interaction is not mentioned in the FDA approved prescribing information either. Overall, there is little to no evidence that nitrofurantoin causes an issue here. Therefore, I don’t think that nitrofurantoin will cause your birth control to be less effective. However, if you’d like to add a bit more certainty, it might be a good idea to have your partner use a condom until you finish your course of nitrofurantoin.

I hope this helps and feel free to write us again in the future!