Antibiotics and birth control pills are both widely used, and usually very effective. Antibiotics, such as penicillin, rid our body of harmful bacteria or microorganisms that cause infections. Birth control pills produce hormones, estrogen, and progestin, that prohibit an egg from becoming fertilized by sperm and implanting in the uterus. These two medications may appear important yet unrelated, but depending upon your antibiotic it could impact the effectiveness of your birth control pills.
According to Walgreen's Pharmacy, antibiotics taken orally can decrease the effectiveness of orally-taken contraceptives, also known as birth control pills. This occurs because oral antibiotics kill not only the infection-causing bacteria but also the general bacteria living in the stomach known as "norma flora."This "norma flora" is also responsible for absorbing the birth control pill into the bloodstream. Therefore, while the antibiotic is doing its job killing off all bacteria in sight, it is also killing off the microorganisms that are needed for birth control to be properly utilized and absorbed. This, in turn, can lead to a higher risk of unplanned pregnancy.
One antibiotic that has the greatest chance of impacting the effectiveness of the pill is rifampin. Rifampin is typically used to treat tuberculosis and other classes of bacterial infections. Through scientific testing, rifampin has proven to reduce "plasma estrogen concentrations". The reported reduction in estrogen, one of the key hormones utilized in birth control pills, demonstrates that rifampin is an antibiotic risk to birth control pill absorption. Other common antibiotics such as amoxicillin and penicillin could have an effect on birth control, but to a reported, "lesser extent" than rifampin.
Oral antibiotics are the most common form of antibiotics prescribed, along with oral contraceptive which is one of the most common forms of birth control prescribed. Some sure signs that antibiotics are weakening the effectiveness of birth control is if "spotting," light bleeding in between menstrual cycles, occurs. If this is noticed or you are taking oral contraceptives and antibiotics simultaneously, be cautious and use spermicide or condom during sexual activity as added protection against pregnancy.
Be safe and smart to avoid a medical mishap!