Drug Interactions
Some drugs reduce the effect of the Pill and can cause breakthrough bleeding, or increased chance of pregnancy. These include drugs such as rifampicin, barbiturates, phenytoin and carbamazepine. In addition cautions are given about broad spectrum antibiotics, such as ampicillin and doxycycline, which may cause problems "by impairing the bacterial flora responsible for recycling ethinylestradiol from the large bowel" (BNF 2003).
The traditional medicinal herb St John's Wort has also been implicated due to its upregulation of the P450 system in the liver.
Read more about this topic: Combined Oral Contraceptive Pill
Famous quotes containing the words drug and/or interactions:
“He’d been numb a long time, years. All his nights down Ninsei, his nights with Linda, numb in bed and numb at the cold sweating center of every drug deal. But now he’d found this warm thing, this chip of murder. Meat, some part of him said. It’s the meat talking, ignore it.”
—William Gibson (b. 1948)
“Whereas children can learn from their interactions with their parents how to get along in one sort of social hierarchy—that of the family—it is from their interactions with peers that they can best learn how to survive among equals in a wide range of social situations.”
—Zick Rubin (20th century)