Antibiotics and Birth Control

Birth control or contraceptive pills are the medications used to prevent pregnancy or conception. It is one of the most effective methods of family planning to avoid unplanned pregnancies. These oral contraceptive pills, actually contain either or both the hormones known as, estrogen and progesterone, to control ovulation. Ovulation is the process of releasing an egg from the ovary, that takes place each month. If ovulation does not take place, fertilization, i.e, pregnancy cannot occur.

On the other hand, antibiotics are a class of drugs that can kill disease-causing microorganisms, mainly bacteria. Hence, they can cure bacterial infection. So, both these pills are two different types of drugs. However, over the years, many people have suspected that antibiotics can reduce or diminish the effectiveness of oral contraceptive pills.

The Effect of Antibiotics on the Efficiency of Contraceptives
Due to lack of enough scientific evidence, it cannot be said that antibiotics can in any way the reduce the efficacy of birth control pills. The entire issue is a bit controversial. Over the years, many cases of unexpected pregnancies have been reported by women who were on both these medications. So, it is suspected that some antibiotics have the ability to interfere with the working of birth control pills. At the same time, it has to be taken into account that enough medical or scientific researches or studies have not been carried out to prove the suspected link between these two drugs.

Therefore, experts are of the opinion that only a small percentage of women can experience the problem of reduced effectiveness of their birth control pills, while taking antibiotics. It is supposed that some birth control pills have low dosage of the hormones and hence their effect on the body may get overpowered by the effects of strong antibiotics. Another possibility is that some medications like antibiotics can have an effect on the ability of the liver to breakdown hormones, like estrogen. An increase in the breakdown of estrogen, as stimulated by the antibiotics, can lower its level in the body and thereby reduce the efficacy of birth control pills.

Again, antibiotics are known for their ability to kill the bacteria (both harmful and beneficial bacteria) that inhabit human intestine. As has been mentioned already, the liver breaks down estrogen into other chemicals, which are then passed into the intestine. In the intestine, these chemicals are again converted into active estrogen by the intestinal bacteria. Therefore, the efficacy of birth control pills to a great extent depends on the intestinal bacteria and hence their destruction affects the effectiveness of oral contraceptives. In addition to these, many instances of menstrual irregularities have been reported by women who take antibiotics and who were on contraceptives.

Drugs That can Interfere With Birth Control Pills
Among antibiotics, rifampin has been found to reduce the effectiveness of oral contraceptive pills, the most. Other antibiotics that too, can interact with birth control pills include penicillin, amoxicillin, tetracycline, griseofulvin, minocycline, sulfonamide, cotrimoxazole, nitrofurantoin and ampicillin. Apart from antibiotics, several other medications are also supposed to interfere with the proper functioning of birth control pills, for example, phenobarbital is believed to have an effect on the efficiency of birth control pills. Phenobarbital is basically a sedative, that is used for the treatment of sleep disorders, anxiety and tension.

Though, there are not enough evidences to support the link between antibiotics and contraception, it is better to be on the safer side. Women who do not want unplanned pregnancies should consider alternative birth control methods while taking antibiotics. However, this does not mean that they cannot continue with their oral contraceptives. Instead, they can take the help of both oral contraceptives and other birth control methods, like intrauterine devices, rather than relying only on birth control pills.