Amoxicillin is a type of antibiotic available by prescription to treat various bacterial infections such as ear infections, gonorrhea, and pneumonia. Taking amoxicillin with birth control, specifically hormonal contraceptives such as birth control pills, can reduce the effectiveness of these contraceptives in a small percentage of cases, increasing the risk of an unplanned pregnancy. Some studies indicate that this only occurs in about 1% of cases, but many healthcare professionals commonly recommend using a barrier contraceptive method such as condoms or diaphragms while taking amoxicillin. Combining the medication and hormonal birth control does not commonly result in other serious side effects, and medical professionals do not usually recommend that a woman stop taking hormonal contraceptives while taking this antibiotic.
Several scientific studies have been done on the interaction between hormonal birth control and antibiotics, and it has been proven that antibiotics can have an effect on how the body metabolizes contraceptives. Hormonal contraceptives prevent pregnancy by regulating hormone levels. The hormones in these pills are metabolized by the liver and then enter the intestine, where they interact with the normal bacterial flora, and then they are eventually absorbed by the body. Antibiotics kill bacteria, both that which causes infection and that which normally lives in the intestine. This can interfere with the absorption of hormonal contraceptives, increasing the risk of unplanned pregnancy.
Most studies indicate that taking amoxicillin with birth control does not affect the hormonal levels in the body significantly. Only one kind of antibiotic, rifampin, has been found to significantly reduce the effectiveness of hormonal contraceptives. Based on this research, organizations such as the World Health Organization and Planned Parenthood have stated that there is no increased risk of an unplanned pregnancy when taking amoxicillin. It is possible, though not scientifically proven, that the effectiveness of low-dose contraceptive pills is more likely to be compromised when taking this medication. Using a barrier method of contraception will significantly decrease the risk of becoming pregnant when taking any kind of antibiotic.
There are no specific side effects of taking amoxicillin and birth control pills, but both of these medications can cause side effects on their own. Common side effects of amoxicillin include diarrhea and yeast infections. Side effects of hormonal birth control can include nausea and headaches. Allergic reactions, including breathing difficulties and hives, are possible when taking either of these medications, and a woman should seek medical attention if experiencing such symptoms.
