Effects of antibiotics on birth control pills

Antibiotics are widely used for the treatment of various infectious diseases. During the anti-infective therapy, women can take oral contraceptives to avoid unwanted pregnancy. However, before you start taking these drugs at the same time, you should learn the information about the effects of antibiotics on birth control pills.

Therapeutic effect of oral contraceptives is based on an increase in the levels of estrogens and progestins – the main female sex hormones. Contraceptive medications block the ovulation of the egg, which makes its fertilization impossible.

Antibiotics do not directly affect the organs or systems of the body. They influence micro-pathogens. After the administration of antibiotics, the bacteria die or lose their ability to reproduce. Thus, the symptoms of infection disappear.

At first glance, antibiotics and birth control pills have completely different drug targets, and they should not have a material impact over the therapeutic effects of each other. But if you go deeper into the action mechanisms of each of the drugs, you can find out how they affect each other.

Broad-spectrum antibacterial drugs inhibit the specific intestinal enzymes that are necessary for the absorption of certain drugs, including estrogen-containing drugs. After the ingestion, contraceptive medications interact with glucuronic acid in the liver.

Glucuronides are excreted with the bile into the intestine, where they are hydrolysed under the influence of intestinal enzymes, and the hormones are released. When the estrogen-containing drugs re-enter the blood, they provide the therapeutic effect – prevent conception.

Thus, a rapid and complete absorption of oral contraceptives requires a normal intestinal microflora. By inhibiting specific intestinal enzymes, antibiotics decrease the effectiveness of birth control pills.

Women can avoid unwanted pregnancy during the antibiotic therapy. To do this, the need to follow several recommendations:

• while taking antibiotics with estrogen-containing drugs, they should use a barrier contraceptive method (condoms, diaphragms, cervical caps, etc.);
• the use of additional contraceptives should be extended for at least 1 week after the end of antibiotic therapy.

During the anti-infective therapy, women should not increase the dosage of antibiotics and birth control pills. Spotting may be the first indication that higher doses of the antibiotic decrease the effectiveness of birth control pills.

Overdose of drugs can provide toxic effects on internal organs. The interaction of high doses of antibiotics and oral contraceptives negatively affect the liver and bile duct.

Before using estrogen-containing drugs during the antibiotic therapy, women should consult a doctor. The medical specialist will be able to choose medications that will protect the patient from infectious diseases and unwanted pregnancy without causing serious side effects at the same time.