Azurette (Page 2 of 10)

Distribution

Etonogestrel, the active metabolite of desogestrel, was found to be 99% protein bound, primarily to sex hormone-binding globulin (SHBG). Ethinyl estradiol is approximately 98.3% bound, mainly to plasma albumin. Ethinyl estradiol does not bind to SHBG, but induces SHBG synthesis. Desogestrel, in combination with ethinyl estradiol, does not counteract the estrogen-induced increase in SHBG, resulting in lower serum levels of free testosterone (96 to 99).

Metabolism

Desogestrel

Desogestrel is rapidly and completely metabolized by hydroxylation in the intestinal mucosa and on first pass through the liver to etonogestrel. Other metabolites (i.e., 3a-OH-desogestrel, 3ß-OH-desogestrel, and 3a-OH-5a-H-desogestrel) with no pharmacologic actions also have been identified and these metabolites may undergo glucuronide and sulfate conjugation.

Ethinyl estradiol

Ethinyl estradiol is subject to a significant degree of presystemic conjugation (phase II metabolism). Ethinyl estradiol escaping gut wall conjugation undergoes phase I metabolism and hepatic conjugation (phase II metabolism). Major phase I metabolites are 2-OH-ethinyl estradiol and 2-methoxy-ethinyl estradiol. Sulfate and glucuronide conjugates of both ethinyl estradiol and phase I metabolites, which are excreted in bile, can undergo enterohepatic circulation.

Excretion

Etonogestrel and ethinyl estradiol are excreted in urine, bile, and feces. At steady state, on Day 21, the elimination half-life of etonogestrel is 27.8 ± 7.2 hours and the elimination half-life of ethinyl estradiol for the combination tablet is 23.9 ± 25.5 hours. For the 0.01 mg ethinyl estradiol tablet [light-blue], the elimination half-life at steady state, Day 28, is 18.9 ± 8.3 hours.

Special Populations

Race

There is no information to determine the effect of race on the pharmacokinetics of Azurette.

Hepatic Insufficiency

No formal studies were conducted to evaluate the effect of hepatic disease on the disposition of Azurette.

Renal Insufficiency

No formal studies were conducted to evaluate the effect of renal disease on the disposition of Azurette.

Drug-Drug Interactions

Interactions between desogestrel/ethinyl estradiol and other drugs have been reported in the literature. No formal drug-drug interaction studies were conducted (see PRECAUTIONS section).

INDICATIONS AND USAGE

Azurette^® (desogestrel/ethinyl estradiol and ethinyl estradiol tablets USP) is indicated for the prevention of pregnancy in women who elect to use this product as a method of contraception.

Oral contraceptives are highly effective. Table II lists the typical accidental pregnancy rates for users of combination oral contraceptives and other methods of contraception. The efficacy of these contraceptive methods, except sterilization, depends upon the reliability with which they are used. Correct and consistent use of these methods can result in lower failure rates.

TABLE II: Percentage of women experiencing an unintended pregnancy during the first year of typical use and the first year of perfect use of contraception and the percentage continuing use at the end of the first year, United States.

	% of Women Experiencing an Unintended Pregnancy within the First Year of Use		% of Women Continuing Use at One Year * (4)
Method (1)	Typical Use † (2)	Perfect Use ‡ (3)
Chance §	85	85
Spermicides ¶	26	6	40
Periodic Abstinence	25		63
Calendar		9
Ovulation Method		3
Sympto-Thermal #		2
Post-Ovulation		1
Withdrawal	19	4
Cap Þ
Parous Women	40	26	42
Nulliparous Women	20	9	56
Sponge
Parous Women	40	20	42
Nulliparous Women	20	9	56
Diaphragm Þ	20	6	56
Condom ß
Female (Reality)	21	5	56
Male	14	3	61
Pill	5		71
Progestin Only		0.5
Combined		0.1
IUD
Progesterone T	2	1.5	81
Copper T 380A	0.8	0.6	78
LNg 20	0.1	0.1	81
Depo-Provera	0.3	0.3	70
Norplant and Norplant-2	0.05	0.05	88
Female Sterilization	0.5	0.5	100
Male Sterilization	0.15	0.10	100
Adapted from Hatcher et al., 1998, ref #1.