AJN, American Journal of Nursing:
Aschenbrenner, Diane S. MS, APRN-BC
Diane S. Aschenbrenner is the course coordinator for undergraduate pharmacology at Johns Hopkins University School of Nursing in Baltimore, MD. She also coordinates Drug Watch: email@example.com.
* Natazia is a newly approved oral contraceptive that has four phases of estrogen and progestin strengths.
* Natazia shouldn't be prescribed for patients taking inducers of the CYP3A4 isoenzyme.
The first four-phase oral contraceptive, Natazia, has been approved by the Food and Drug Administration (FDA). Like most other oral contraceptives, Natazia is a combination of an estrogen and a progestin, although this is the first pill to use the estrogen estradiol valerate. The levels of estrogen and progestin in an oral contraceptive vary throughout the 28-day cycle of drug administration. In the case of Natazia, there are four different combinations of hormone levels (hence the description "four phase"); before the approval of Natazia, combination pills had either two or three level changes. Because Natazia is metabolized through the CYP3A4 isoenzyme of the cytochrome P-450 enzyme system, women who take drugs that are strong inducers of CYP3A4, such as carbamazepine (Tegretol and others), phenytoin (Dilantin, Phenytek), rifampin (also known as rifampicin; Rifadin, Rimactane), and St. John's wort, shouldn't take Natazia because those drugs can lower the circulating levels of estrogen and progestin, decreasing the contraceptive's effectiveness. Adverse effects are similar to those of all other oral contraceptives and include "headaches, irregular uterine bleeding, breast tenderness, headaches, nausea [and] vomiting, acne, and increased weight."
Patient education regarding starting contraception with Natazia and continued use of the drug is important, so women can maximize therapeutic effectiveness and prevent pregnancy. The first pill should be taken on the first day of a menstrual cycle (the first day of bleeding). One pill should be taken daily at the same time of day. The pills should be taken in order as noted on the blister pack because of the varied hormone levels. If a woman is switching to Natazia from another hormonal birth control method (such as a vaginal ring, a patch, an intrauterine device, implant, or injections), she should begin taking Natazia the day she stops the other method. If she's switching from another oral contraceptive, she should start on the first day of her withdrawal bleeding (the monthly bleeding, which isn't actually a period, that typically occurs when she's taking the pills that contain no hormone). Regardless of which method was used previously, women should also use a nonhormonal birth control for the first nine days after starting Natazia. Postpartum women should wait at least a month after giving birth before starting Natazia, although breastfeeding women should avoid Natazia and other oral contraceptives altogether; they should use a nonhormonal form of birth control. To see the press release from the FDA, go to http://bit.ly/ay2qj0; to read the complete prescribing information, go to http://bit.ly/aCS6xQ.
© 2010 Lippincott Williams & Wilkins, Inc.