Antibiotic Effects on Birth Control

It has not been conclusively proven that antibiotics destroy the efficacy of oral contraceptives. However, there is some evidence--some of which is anecdotal and presented by women who have personally experienced this conundrum--that suggests that antibiotics can in fact interfere with the effectiveness of oral contraceptives.

Possible Interference

• Medicinenet.com explains that the possibility of interference occurs because antibiotics may reduce the recirculation of estrogen. It is thought that antibiotics may eliminate the bacteria that is required to convert inactive chemicals into active estrogen. Oral contraceptives contain ethinyl estradiol, with is an estrogen. This element is broken down in the liver and converted into other chemicals. These chemicals go into the intestines and into the bile that is produced by the liver. The chemicals are then converted back into active estrogen by the bacteria in the intestine, and this estrogen is reabsorbed into the body. If this process is thwarted by the introduction of antibiotics, an unintended pregnancy could occur.

Ampicillin and Tetracycline

• Dr. Frederick R. Jelovsek of Wdxcyber.com notes that certain antibiotics, such as ampicillin and tetracycline, are two drugs that are highly suspected when it comes to interfering with the efficacy of oral contraceptives.

Rifampin

• One particular antibiotic that is taken by those who have tuberculosis is called rifampin. Rifampin has been clearly shown to interfere with the efficacy of oral contraceptives as it prevents ovulation, according to The Journal of American Medical Association (JAMA).

Low-Dose Oral Contraceptives

• Although the jury is still out on how drastically antibiotics, across the board, impact the effectiveness of birth control, some physicians believe that women who are taking low-dose oral contraceptives could be more susceptible to a birth control failure if antibiotics are taken, according to The Faculty of Family Practice and Reproductive Health Care (see Resources).

Considerations

• In an article written by Allison Pruitt for the Daily Mississippian, she quotes Dr. Barbara Collier, director of student health services at the Student Health Center at the University of Mississippi, who notes that antibiotics do have the potential of preventing the body from getting the hormones released by birth control pills that are needed to provide effective contraception as both oral contraceptives and antibiotics are metabolized by the body.

Play It Safe

• If you are taking an oral contraceptive and must take an antibiotic because you are sick, it is recommended that you use a backup birth control plan, including a barrier method (condoms). Err on the side of caution and doubly protect yourself.