Routes of administration

Routes of administration

Sven O. Skouby

Dept. OB/GYN, Frederiksberg Hospital, University of

Copenhagen, Denmark

Women who want safe, effective contraception have many more

options than they did only a few years ago. Each option must be weighed

carefully according to the needs and lifestyle of each particular woman.

Combined oral contraceptives (OCs) are still the preferred choice for the

majority of European women although the once daily administration result in

fluctuation of hormone plasma levels that may increase the incidence of side


The only contraceptive patch marketed, Evra®, delivers

norelgestromin and ethinyl estradiol (EE) transdermally. The patch is applied

once a week. Pharmacokinetic studies have shown that the concentrations of

norelgestromin and EE are within the ranges seen with OCs containing

norgestimate 250 µg and EE 35 µg, but without the peaks and the absorption

avoids the first-pass metabolism. The drug levels have been noted to remain

unaffected during conditions of heat, humidity, and exercise. The method failure

Pearl index is 0.7 and the incidence of adverse similar to that observed during

use of OCs. However, the patch seems to have a higher adherence rate for younger

users. A month’s supply is more expensive compared to OCs but may show cost

saving attributed to reduced costs of pregnancy.

The Nuva® vaginal ring is a soft, flexible, transparent polymer

and delivers etonogestrel and ethinyl estradiol The hormonal dose is comparable

to a pill containing 150 µg desogestrel and 30 µg EE. The advantage of the

ring is once-a-month insertion. However, if the ring is out of the vagina for

more than 3 hours, a back-up method is needed. When compared to OCs, the

incidence of irregular bleeding appears similar. Users of the ring group report

higher incidence of vaginal discomfort, but few feel the ring during intercourse.

The contraceptive patch and the vaginal ring offer additional

choice for women who wish to use a combined hormonal method of contraception

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