ORTHO TRI-CYCLEN® LO TABLETS
(norgestimate/ethinyl estradiol)

Patients should be counseled that this product does not protect against HIV infection (AIDS) and other sexually transmitted diseases.

DESCRIPTION

ORTHO TRI-CYCLEN® Lo Tablets is a combination oral contraceptive containing the progestational compound norgestimate and the estrogenic compound ethinyl estradiol.

ORTHO TRI-CYCLEN® Lo Tablets

Each white tablet contains 0.180 mg of the progestational compound, norgestimate (+)-13-Ethyl-17-hydroxy-18, 19-dinor-17α-pregn-4-en-20-yn-3-one oxime acetate (ester) and 0.025 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna,1,3,5(10)-trien-20-yne-3,17-diol). Inactive ingredients include lactose, magnesium stearate, croscarmellose sodium, microcrystalline cellulose, carnauba wax, hypromellose, polyethylene glycol, titanium dioxide, and purified water.

Each light blue tablet contains 0.215 mg of the progestational compound norgestimate (+)-13-Ethyl-17-hydroxy-18, 19-dinor-17α-pregn-4-en-20-yn-3-one oxime acetate (ester) and 0.025 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna,1,3,5(10)-trien-20-yne-3,17-diol). Inactive ingredients include FD & C Blue No. 2 Aluminum Lake, lactose, magnesium stearate, croscarmellose sodium, microcrystalline cellulose, carnauba wax, hypromellose, polyethylene glycol, titanium dioxide, and purified water.

Each dark blue tablet contains 0.250 mg of the progestational compound norgestimate (+)-13-Ethyl-17-hydroxy-18, 19-dinor-17α-pregn-4-en-20-yn-3-one oxime acetate (ester) and 0.025 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna,1,3,5(10)-trien-20-yne-3,17-diol). Inactive ingredients include FD & C Blue No. 2 Aluminum Lake, lactose, magnesium stearate, croscarmellose sodium, microcrystalline cellulose, polysorbate 80, carnauba wax, hypromellose, polyethylene glycol, titanium dioxide, and purified water.

Each dark green tablet contains only inert ingredients, as follows: FD & C Blue No. 2 Aluminum Lake, lactose, magnesium stearate, pregelatinized starch, ferric oxide, hypromellose, polyethylene glycol, titanium dioxide, talc and purified water.

                                               Norgestimate

                                               Ethinyl Estradiol

CLINICAL PHARMACOLOGY

Oral Contraception

Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increase the difficulty of sperm entry into the uterus) and the endometrium (which reduce the likelihood of implantation).

Receptor binding studies, as well as studies in animals and humans, have shown that norgestimate and 17-deacetyl norgestimate, the major serum metabolite, combine high progestational activity with minimal intrinsic androgenicity.90–93 Norgestimate, in combination with ethinyl estradiol, does not counteract the estrogen-induced increases in sex hormone binding globulin (SHBG), resulting in lower serum testosterone.90,91,94

PHARMACOKINETICS

Absorption

Norgestimate (NGM) and ethinyl estradiol (EE) are rapidly absorbed following oral administration. Norgestimate is rapidly and completely metabolized by first-pass (intestinal and/or hepatic) mechanisms to norelgestromin (NGMN) and norgestrel (NG), which are the major active metabolites of norgestimate. Mean pharmacokinetic parameters for NGMN, NG and EE during three cycles of administration of ORTHO TRI-CYCLEN® Lo are summarized in Table 1. These results indicate that: (1) Peak serum concentrations of NGMN and EE were generally reached by 2 hours after dosing; (2) Accumulation following multiple dosing of the 180 mcg NGM / 25 mcg dose is approximately 1.5 to 2 fold for NGMN and approximately 1.5 fold for EE compared with single dose administration, in agreement with that predicted based on linear kinetics of NGMN and EE; (3) The kinetics of NGMN are dose proportional following NGM doses of 180 to 250 mcg; (4) Steady-state conditions for NGMN following each NGM dose and for EE were achieved during the three cycle study; (5) Non-linear accumulation (4.5–14.5 fold) of norgestrel was observed as a result of high affinity binding to SHBG, which limits its biological activity.100 The effect of food on the pharmacokinetics of ORTHO TRI-CYCLEN® Lo has not been studied.

Table 1 provides a summary of norelgestromin, norgestrel and ethinyl estradiol pharmacokinetic parameters.

Distribution

Norelgestromin and norgestrel (a serum metabolite of norelgestromin) are highly bound (>97%) to serum proteins. Norelgestromin is bound to albumin and not to SHBG, while norgestrel is bound primarily to SHBG. Ethinyl estradiol is extensively bound (>97%) to serum albumin.

Metabolism

Norgestimate is extensively metabolized by first-pass mechanisms in the gastrointestinal tract and/or liver. Norgestimate's primary active metabolite is norelgestromin. Subsequent hepatic metabolism of norelgestromin occurs and metabolites include norgestrel, which is also active and various hydroxylated and conjugated metabolites. Ethinyl estradiol is also metabolized to various hydroxylated products and their glucuronide and sulfate conjugates.

Excretion

Following 3 cycles of administration of ORTHO TRI-CYCLEN® Lo, the mean (± SD) elimination half-life values, at steady-state, for norelgestromin, norgestrel and ethinyl estradiol were 28.1 (± 10.6) hours, 36.4 (± 10.2) hours and 17.7 (± 4.4) hours, respectively (Table 1). The metabolites of norelgestromin and ethinyl estradiol are eliminated by renal and fecal pathways.

Special Populations

Effects of Body Weight, Body Surface Area, and Age

The effects of body weight, body surface area, age and race on the pharmacokinetics of norelgestromin, norgestrel and ethinyl estradiol were eva luated in 79 healthy women using pooled data following single dose administration of NGM 180 or 250 mcg / EE 25 mcg tablets in four pharmacokinetic studies. Increasing body weight and body surface area were each associated with decreases in Cmax and AUC0–24h values for norelgestromin and ethinyl estradiol and increases in CL/F (oral clearance) for ethinyl estradiol. Increasing body weight by 10 kg is predicted to reduce the following parameters: NGMN Cmax by 9% and AUC0–24h by 19%, norgestrel Cmax by 12% and AUC0–24h by 46%, EE Cmax by 13% and AUC0–24h by 12%. These changes were statistically significant. Increasing age was associated with slight decreases (6% with increasing age by 5 years) in Cmax and AUC0–24h for norelgestromin and were statistically significant, but there was no significant effect for norgestrel or ethinyl estradiol. Only a small to moderate fraction (5–40%) of the overall variability in the pharmacokinetics of norelgestromin and ethinyl estradiol following ORTHO TRI-CYCLEN® Lo Tablets may be explained by any or all of the above demographic parameters.

In clinical studies involving 1673 subjects with a mean weight of 141 pounds, there was no association between pregnancy and weight.

Renal and Hepatic Impairment

No studies with ORTHO TRI-CYCLEN® Lo have been conducted in women with renal or hepatic impairment.

Drug-Drug Interactions

Although norelgestromin and its metabolites inhibit a variety of P450 enzymes in human liver microsomes, under the recommended dosing regimen, the in vivo concentrations of norelgestromin and its metabolites, even at the peak serum levels, are relatively low compared to the inhibitory constant (Ki).

Interactions between oral contraceptives and other drugs have been reported in the literature. No formal drug-drug interaction studies were conducted with ORTHO TRI-CYCLEN® Lo (see PRECAUTIONS).

INDICATIONS AND USAGE

ORTHO TRI-CYCLEN® Lo Tablets are indicated for the prevention of pregnancy in women who elect to use oral contraceptives as a method of contraception.

In an active controlled clinical trial 1,673 subjects completed 11,003 cycles of ORTHO TRI-CYCLEN® Lo use and a total of 20 pregnancies were reported in ORTHO TRI-CYCLEN® Lo users.99 This represents an overall use-efficacy (typical user efficacy) pregnancy rate of 2.36 per 100 women-years of use.

Oral contraceptives are highly effective for pregnancy prevention. Table 2 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, the IUD, and the Norplant® system, depends upon the reliability with which they are used. Correct and consistent use of methods can result in lower failure rates.

ORTHO TRI-CYCLEN® Lo has not been studied for and is not indicated for use in emergency contraception.

CONTRAINDICATIONS

Oral contraceptives should not be used in women who have any of the following conditions:

• Thrombophlebitis or thromboembolic disorders
• A past history of deep vein thrombophlebitis or thromboembolic disorders
• Cerebral vascular or coronary artery disease (current or history)
• Valvular heart disease with complications
• Severe hypertension
• Diabetes with vascular involvement
• Headaches with focal neurological symptoms
• Major surgery with prolonged immobilization
• Known or suspected carcinoma of the breast or personal history of breast cancer
• Carcinoma of the endometrium or other known or suspected estrogen-dependent neoplasia
• Undiagnosed abnormal genital bleeding
• Cholestatic jaundice of pregnancy or jaundice with prior pill use
• Hepatic adenomas or carcinomas
• Known or suspected pregnancy
• Hypersensitivity to any component of this product

WARNINGS

The use of oral contraceptives is associated with increased risks of several serious conditions including myocardial infarction, thromboembolism, stroke, hepatic neoplasia, and gallbladder disease, although the risk of serious morbidity or mortality is very small in healthy women without underlying risk factors. The risk of morbidity and mortality increases significantly in the presence of other underlying risk factors such as hypertension, hyperlipidemias, obesity and diabetes.

Practitioners prescribing oral contraceptives should be familiar with the following information relating to these risks.

The information contained in this package insert is principally based on studies carried out in patients who used oral contraceptives with higher formulations of estrogens and progestogens than those in common use today. The effect of long-term use of the oral contraceptives with lower formulations of both estrogens and progestogens remains to be determined.

Throughout this labeling, epidemiological studies reported are of two types: retrospective or case control studies and prospective or cohort studies. Case control studies provide a measure of the relative risk of a disease, namely, a ratio of the incidence of a disease among oral contraceptive users to that among nonusers. The relative risk does not provide information on the actual clinical occurrence of a disease. Cohort studies provide a measure of attributable risk, which is the difference in the incidence of disease between oral contraceptive users and nonusers. The attributable risk does provide information about the actual occurrence of a disease in the population (adapted from refs. 2 and 3 with the author's permission). For further information, the reader is referred to a text on epidemiological methods.

1. Thromboembolic Disorders and Other Vascular Problems

a. Myocardial Infarction

An increased risk of myocardial infarction has been attributed to oral contraceptive use. This risk is primarily in smokers or women with other underlying risk factors for coronary artery disease such as hypertension, hypercholesterolemia, morbid obesity, and diabetes. The relative risk of heart attack for current oral contraceptive users has been estimated to be two to six.4–10 The risk is very low under the age of 30.

Smoking in combination with oral contraceptive use has been shown to contribute substantially to the incidence of myocardial infarctions in women in their mid-thirties or older with smoking accounting for the majority of excess cases.11 Mortality rates associated with circulatory disease have been shown to increase substantially in smokers, especially in those 35 years of age and older and in nonsmokers over the age of 40 among women who use oral contraceptives.

Figure 1: Circulatory Disease Mortality Rates per 100,000 Women-Years by Age, Smoking Status and Oral Contraceptive Use

Figure 1 Adapted from P.M. Layde and V. Beral, Ref. #12.

Oral contraceptives may compound the effects of well-known risk factors, such as hypertension, diabetes, hyperlipidemias, age and obesity.13 In particular, some progestogens are known to decrease HDL cholesterol and cause glucose intolerance, while estrogens may create a state of hyperinsulinism.14–18 Oral contraceptives have been shown to increase blood pressure among users (see section 9 in WARNINGS). Similar effects on risk factors have been associated with an increased risk of heart disease. Oral contraceptives must be used with caution in women with cardiovascular disease risk factors.

Norgestimate has minimal androgenic activity (see CLINICAL PHARMACOLOGY), and there is some evidence that the risk of myocardial infarction associated with oral contraceptives is lower when the progestogen has minimal androgenic activity than when the activity is greater.97

b. Thromboembolism

An increased risk of thromboembolic and thrombotic disease associated with the use of oral contraceptives is well established. Case control studies have found the relative risk of users compared to nonusers to be 3 for the first episode of superficial venous thrombosis, 4 to 11 for deep vein thrombosis or pulmonary embolism, and 1.5 to 6 for women with predisposing conditions for venous thromboembolic disease.2,3,19–24 Cohort studies have shown the relative risk to be somewhat lower, about 3 for new cases and about 4.5 for new cases requir