norgestimate and ethinyl estradiol
Dosage Form: tablets
Tri-Sprintec®
(norgestimate and ethinyl estradiol tablets - triphasic regimen)
PATIENTS SHOULD BE COUNSELED THAT THIS PRODUCT DOES NOT PROTECT AGAINST HIV INFECTION (AIDS) AND OTHER SEXUALLY TRANSMITTED DISEASES.
Rx only
Tri-Sprintec Description
Tri-Sprintec® Tablets are a combination oral contraceptive containing the progestational compound norgestimate and the estrogenic compound ethinyl estradiol.
Each gray tablet contains 0.18 mg of the progestational compound, norgestimate (18, 19-Dinor-17-pregn-4-en-20-yn-3-one,17-(acetyloxy)-13-ethyl-oxime, (17α)-(+)-) and 0.035 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna, 1,3,5(10)-trien-20-yne-3, 17-diol), and the inactive ingredients include anhydrous lactose, lactose monohydrate, lake blend black LB 636 (ingredients include aluminum sulfate solution, aluminum-chloride solution, FD&C blue no. 2, FD&C red no. 40, FD&C yellow no. 6, sodium bicarbonate and sodium carbonate), magnesium stearate, and pregelatinized starch.
Each light blue tablet contains 0.215 mg of the progestational compound norgestimate (18, 19-Dinor-17-pregn-4-en-20-yn-3-one,17-(acetyloxy)-13-ethyl-,oxime, (17α)-(+)-) and 0.035 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna, 1,3,5(10)-trien-20-yne-3, 17-diol), and the inactive ingredients include anhydrous lactose, FD&C blue no. 2 aluminum lake, (ingredients include aluminum sulfate solution, aluminum-chloride solution, sodium bicarbonate and sodium carbonate), lactose monohydrate, magnesium stearate, and pregelatinized starch.
Each blue tablet contains 0.25 mg of the progestational compound norgestimate (18, 19-Dinor-17-pregn-4-en-20-yn-3-one,17-(acetyloxy)-13-ethyl-, oxime, (17α)-(+)-) and 0.035 mg of the estrogenic compound, ethinyl estradiol (19-nor-17α-pregna, 1,3,5(10)-trien-20-yne-3, 17-diol), and the inactive ingredients include anhydrous lactose, FD&C blue no. 2 aluminum lake, (ingredients include aluminum sulfate solution, aluminum-chloride solution, sodium bicarbonate and sodium carbonate), lactose monohydrate, magnesium stearate, and pregelatinized starch.
Each white tablet contains only inert ingredients as follows: anhydrous lactose, hypromellose, magnesium stearate, and microcrystalline cellulose.
The structural formula is as follows:
Tri-Sprintec - 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
Acne
Acne is a skin condition with a multifactorial etiology. The combination of ethinyl estradiol and norgestimate may increase sex hormone binding globulin (SHBG) and decrease free testosterone resulting in a decrease in the severity of facial acne in otherwise healthy women with this skin condition.
Norgestimate and ethinyl estradiol are well absorbed following oral administration of Tri-Sprintec. On the average, peak serum concentrations of norgestimate and ethinyl estradiol are observed within two hours (0.5 to 2 hr for norgestimate and 0.75 to 3 hr for ethinyl estradiol) after administration followed by a rapid decline due to distribution and elimination. Although norgestimate serum concentrations following single or multiple dosing were generally below assay detection within 5 hours, a major norgestimate serum metabolite, 17-deacetyl norgestimate, (which exhibits a serum half-life ranging from 12 to 30 hours) appears rapidly in serum with concentrations greatly exceeding that of norgestimate. The 17-deacetylated metabolite is pharmacologically active and the pharmacologic profile is similar to that of norgestimate. The elimination half-life of ethinyl estradiol ranged from approximately 6 to 14 hours.
Both norgestimate and ethinyl estradiol are extensively metabolized and eliminated by renal and fecal pathways. Following administration of 14C-norgestimate, 47% (45 to 49%) and 37% (16 to 49%) of the administered radioactivity was eliminated in the urine and feces, respectively. Unchanged norgestimate was not detected in the urine. In addition to 17-deacetyl norgestimate, a number of metabolites of norgestimate have been identified in human urine following administration of radiolabeled norgestimate. These include 18, 19-Dinor-17-pregn-4-en-20-yn-3-one, 17 - hydroxy - 13 - ethyl,(17α) - ( - );18,19 - Dinor - 5 - 17 - pregnan - 20 - yn,3α,17 - dihydroxy - 13 - ethyl,(17α), various hydroxylated metabolites and conjugates of these metabolites. Ethinyl estradiol is metabolized to various hydroxylated products and their glucuronide and sulfate conjugates.
Indications and Usage for Tri-Sprintec
Tri-Sprintec Tablets are indicated for the prevention of pregnancy in women who elect to use oral contraceptives as a method of contraception.
Tri-Sprintec Tablets are indicated for the treatment of moderate acne vulgaris in females, ≥15 years of age, who have no known contraindications to oral contraceptive therapy, desire contraception, have achieved menarche and are unresponsive to topical anti-acne medications.
Oral contraceptives are highly effective. Table I 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 methods can result in lower failure rates.
| |||
| % of Women Experiencing an Unintended Pregnancy within the First Year of Use | % of Women Continuing Use at One Year* | ||
| Method | Typical Use† | Perfect Use‡ | |
| (1) | (2) | (3) | (4) |
| 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 | |
| CapÞ | |||
| Parous Women | 40 | 26 | 42 |
| Nulliparous Women | 20 | 9 | 56 |
| Sponge | |||
| Parous Women | 40 | 20 | 42 |
| Nulliparous Women | 20 | 9 | 56 |
| DiaphragmÞ | 20 | 6 | 56 |
| Condomß | |||
| 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 T380A | 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. | |||
In four clinical trials with norgestimate and ethinyl estradiol, the use-efficacy pregnancy rate ranged from 0.68 to 1.47 per 100 women-years. In total, 4,756 subjects completed 45,244 cycles and a total of 42 pregnancies were reported. This represents an overall use-efficacy rate of 1.21 per 100 women-years. One of these 4 studies was a randomized comparative clinical trial in which 4,633 subjects completed 22,312 cycles. Of the 2,312 patients on norgestimate and ethinyl estradiol, 8 pregnancies were reported. This represents an overall use-efficacy pregnancy rate of 0.94 per 100 women-years.
In two double-blind, placebo-controlled, six month, multicenter clinical trials, norgestimate and ethinyl estradiol showed a statistically significant decrease in inflammatory lesion count and total lesion count (TABLE II). The adverse reaction profile of norgestimate and ethinyl estradiol from these two controlled clinical trials is consistent with what has been noted from previous studies involving norgestimate and ethinyl estradiol and are the known risks associated with oral contraceptives.
| Norgestimate and Ethinyl Estradiol | Placebo | |
| N=163 | N=161 | |
| Mean Age at Enrollment | 27.3 years | 28 |
| Inflammatory Lesions - | 56.6 | 36.6 |
| Mean Percent Reduction | ||
| Total Lesions - | 49.6 | 30.3 |
| Mean Percent Reduction |
Contraindications
Oral contraceptives should not be used in women who currently have the following conditions:
- Thrombophlebitis or thromboembolic disorders
- A past history of deep vein thrombophlebitis or thromboembolic disorders
- Cerebral vascular or coronary artery disease
- Known or suspected carcinoma of the breast
- 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
Warnings
Cigarette smoking increases the risk of serious cardiovascular side effects from oral contraceptive use. This risk increases with age and with heavy smoking (15 or more cigarettes per day) and is quite marked in women over 35 years of age. Women who use oral contraceptives should be strongly advised not to smoke.
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 among women who use oral contraceptives.
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 greater97.
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 requiring hospitalization.25 The risk of thromboembolic disease associated with oral contraceptives is not related to length of use and disappears after pill use is stopped.2
A two- to four-fold increase in relative risk of post-operative thromboembolic complications has been reported with the use of oral contraceptives.9 The relative risk of venous thrombosis in women who have predisposing conditions is twice that of women without such medical conditions.26 If feasible, oral contraceptives should be discontinued at least four weeks prior to and for two weeks after elective surgery of a type associated with an increase in risk of thromboembolism and during and following prolonged immobilization. Since the immediate postpartum period is also associated with an increased risk of thromboembolism, oral contraceptives should be started no earlier than four weeks after delivery in women who elect not to breast-feed or four weeks after a second trimester abortion.
c. Cerebrovascular Diseases: Oral contraceptives have been shown to increase both the relative and attributable risks of cerebrovascular events (thrombotic and hemorrhagic strokes), although, in general, the risk is greatest among older (>35 years), hypertensive women who also smoke. Hypertension was found to be a risk factor for both users and nonusers, for both types of strokes, and smoking interacted to increase the risk of stroke.27-29
In a large study, the relative risk of thrombotic strokes has been shown to range from 3 for normotensive users to 14 for users with severe hypertension.30 The relative risk of hemorrhagic stroke is reported to be 1.2 for nonsmokers who used oral contraceptives, 2.6 for smokers who did not use oral contraceptives, 7.6 for smokers who used oral contraceptives, 1.8 for normotensive users and 25.7 for users with severe hypertension.30 The attributable risk is also greater in older women.3
d. Dose-Related Risk of Vascular Disease from Oral Contraceptives: A positive association has been observed between the amount of estrogen and progestogen in oral contraceptives and the risk of vascular disease.31-33 A decline in serum high density lipoproteins (HDL) has been reported with many progestational agents.14-16 A decline in serum high density lipoproteins has been associated with an increased incidence of ischemic heart disease. Because estrogens increase HDL cholesterol, the net effect of an oral contraceptive depends on a balance achieved between doses of estrogen and progestogen and the activity of the progestogen used in the contraceptives. The activity and amount of both hormones should be considered in the choice of an oral contraceptive.
Minimizing exposure to estrogen and progestogen is in keeping with good principles of therapeutics. For any particular estrogen/progestogen combination, the dosage regimen prescribed should be one which contains the least amount of estrogen and progestogen that is compatible with a low failure rate and the needs of the individual patient. New acceptors of oral contraceptive agents should be started on preparations containing 0.035 mg or less of estrogen.
e. Persistence of Risk of Vascular Disease: There are two studies which have shown persistence of risk of vascular disease for ever-users of oral contraceptives. In a study in the United States, the risk of developing myocardial infarction after discontinuing oral contraceptives persists for at least 9 years for women 40 to 49 years who had used oral contraceptives for five or more years, but this increased risk was not demonstrated in other age groups.8 In another study in Great Britain, the risk of developing cerebrovascular disease persisted for at least 6 years after discontinuation of oral contraceptives, although excess risk was very small.34 However, both studies were performed with oral contraceptive formulations containing 50 micrograms or higher of estrogens.
2. Estimates of Mortality from Contraceptive Use
One study gathered data from a variety of sources which have estimated the mortality rate associated with different methods of contraception at different ages (Table IV). These estimates include the combined risk of death associated with contraceptive methods plus the risk attributable to pregnancy in the event of method failure. Each method of contraception has its specific benefits and risks. The study concluded that with the exception of oral contraceptive users 35 and older who smoke, and 40 and older who do not smoke, mortality associated with all methods of birth control is low and below that associated with childbirth. The observation of an increase in risk of mortality with age for oral contraceptive users is based on data gathered in the 1970's.35 Current clinical recommendation involves the use of lower estrogen dose formulations and a careful consideration of risk factors. In 1989, the Fertility and Maternal Health Drugs Advisory Committee was asked to review the use of oral contraceptives in women 40 years of age and over. The Committee concluded that although cardiovascular disease risks may be increased with oral contraceptive use after age 40 in healthy nonsmoking women (even with the newer low-dose formulations), there are also greater potential health risks associated with pregnancy in older women and with the alternative surgical and medical procedures which may be necessary if such women do not have access to effective and acceptable means of contraception. The Committee recommended that the benefits of low-dose oral contraceptive use by healthy nonsmoking women over 40 may outweigh the possible risks.
Of course, older women, as all women, who take oral contraceptives, should take an oral contraceptive which contains the least amount of estrogen and progestogen that is compatible with a low failure rate and individual patient needs.
| ||||||
| Method of control and outcome | 15-19 | 20-24 | 25-29 | 30-34 | 35-39 | 40-44 |
| No fertility | 7 | 7.4 | 9.1 | 14.8 | 25.7 | 28.2 |
| control methods* | ||||||
| Oral contraceptives | 0.3 | 0.5 | 0.9 | 1.9 | 13.8 | 31.6 |
| nonsmoker† | ||||||
| Oral contraceptives | 2.2 | 3.4 | 6.6 | 13.5 | 51.1 | 117.2 |
| smoker† | ||||||
| IUD† | 0.8 | 0.8 | 1 | 1 | 1.4 | 1.4 |
| Condom* | 1.1 | 1.6 | 0.7 | 0.2 | 0.3 | 0.4 |
| Diaphragm/ | 1.9 | 1.2 | 1.2 | 1.3 | 2.2 | 2.8 |
| spermicide* | ||||||
| Periodic | 2.5 | 1.6 | 1.6 | 1.7 | 2.9 | 3.6 |
| abstinence* | ||||||
| Adapted from H.W. Ory, ref. #35. | ||||||
3. Carcinoma of the Reproductive Organs and Breasts
Numerous epidemiological studies have been performed on the incidence of breast, endometrial, ovarian, and cervical cancer in women using oral contraceptives. While there are conflicting reports, most studies suggest that use of oral contraceptives is not associated with an overall increase in the risk of developing breast cancer. Some studies have reported an increased relative risk of developing breast cancer, particularly at a younger age. This increased relative risk has been reported to be related to duration of use.36-44,79-89
A meta-analysis of 54 studies found a small increase in the frequency of having breast cancer diagnosed for women who were currently using combined oral contraceptives or had used them within the past ten years. This increase in the frequency of breast cancer diagnosis, within ten years of stopping use, was generally accounted for by cancers localized to the breast. There was no increase in the frequency of having breast cancer diagnosed ten or more years after cessation of use.95
Some studies suggest that oral contraceptive use has been associated with an increase in the risk of cervical intraepithelial neoplasia in some populations of women.45-48 However, there continues to be controversy about the extent to which such findings may be due to differences in sexual behavior and other factors.
4. Hepatic Neoplasia
Benign hepatic adenomas are associated with oral contraceptive use, although the incidence of benign tumors is rare in the United States. Indirect calculations have estimated the attributable risk to be in the range of 3.3 cases/100,000 for users, a risk that increases after four or more years of use especially with oral contraceptives of higher dose.49 Rupture of benign, hepatic adenomas may cause death through intra-abdominal hemorrhage.50,51
Studies have shown an increased risk of developing hepatocellular carcinoma52-54,96 in oral contraceptive users. However, these cancers are rare in the U.S.
5. Ocular Lesions
There have been clinical case reports of retinal thrombosis associated with the use of oral contraceptives. Oral contraceptives should be discontinued if there is unexplained partial or complete loss of vision; onset of proptosis or diplopia; papilledema; or retinal vascular lesions. Appropriate diagnostic and therapeutic measures should be undertaken immediately.
6. Oral Contraceptive Use Before or During Early Pregnancy
Extensive epidemiological studies have revealed no increased risk of birth defects in women who have used oral contraceptives prior to pregnancy.56,57 The majority of recent studies also do not indicate a teratogenic effect, particularly in so far as cardiac anomalies and limb reduction defects are concerned,55,56,58,59 when taken inadvertently during early pregnancy.
The administration of oral contraceptives to induce withdrawal bleeding should not be used as a test for pregnancy. Oral contraceptives should not be used during pregnancy to treat threatened or habitual abortion.
It is recommended that for any patient who has missed two consecutive periods, pregnancy should be ruled out before continuing oral contraceptive use. If the patient has not adhered to the prescribed schedule, the possibility of pregnancy should be considered at the time of the first missed period. Oral contraceptive use should be discontinued until pregnancy is ruled out.
7. Gallbladder Disease
Earlier studies have reported an increased lifetime relative risk of gallbladder surgery in users of oral contraceptives and estrogens.60,61 More recent studies, however, have shown that the relative risk of developing gallbladder disease among oral contraceptive users may be minimal.62-64 The recent findings of minimal risk may be related to the use of oral contraceptive formulations containing lower hormonal doses of estrogens and progestogens.
8. Carbohydrate and Lipid Metabolic Effects
Oral contraceptives have been shown to cause a decrease in glucose tolerance in a significant percentage of users.17 This effect has been shown to be directly related to estrogen dose.65 Progestogens increase insulin secretion and create insulin resistance, this effect varying with different progestational agents.17,66 However, in the nondiabetic woman, oral contraceptives appear to have no effect on fasting blood glucose.67 Because of these demonstrated effects, prediabetic and diabetic women in particular should be carefully monitored while taking oral contraceptives.
A small proportion of women will have persistent hypertriglyceridemia while on the pill. As discussed earlier (see WARNINGS, 1a and 1d), changes in serum triglycerides and lipoprotein levels have been reported in oral contraceptive users.
In clinical studies with norgestimate and ethinyl estradiol there were no clinically significant changes in fasting blood glucose levels. Minimal statistically significant changes were noted in glucose levels over 24 cycles of use. Glucose tolerance tests showed no clinically significant changes from baseline to cycles 3, 12, and 24.
9. Elevated Blood Pressure
An increase in blood pressure has been reported in women taking oral contraceptives68 and this increase is more likely in older oral contraceptive users69 and with extended duration of use.61 Data from the Royal College of General Practitioners12 and subsequent randomized trials have shown that the incidence of hypertension increases with increasing progestational activity.
Women with a history of hypertension or hypertension-related diseases, or renal disease70 should be encouraged to use another method of contraception. If women elect to use oral contraceptives, they should be monitored closely and if significant elevation of blood pressure occurs, oral contraceptives should be discontinued. For most women, elevated blood pressure will return to normal after stopping oral contraceptives, and there is no difference in the occurrence of hypertension between former and never users.68-71
10. Headache
The onset or exacerbation of migraine or development of headache with a new pattern which is recurrent, persistent or severe requires discontinuation of oral contraceptives and evaluation of the cause.
11. Bleeding Irregularities
Breakthrough bleeding and spotting are sometimes encountered in patients on oral contraceptives, especially during the first three months of use. Nonhormonal causes should be considered and adequate diagnostic measures taken to rule out malignancy or pregnancy in the event of breakthrough bleeding, as in the case of any abnormal vaginal bleeding. If pathology has been excluded, time or a change to another formulation may solve the problem. In the event of amenorrhea, pregnancy should be ruled out.
Some women may encounter post-pill amenorrhea or oligomenorrhea, especially when such a condition was preexistent.
12. Ectopic Pregnancy
Ectopic as well as intrauterine pregnancy may occur in contraceptive failures.
Precautions
1. Physical Examination and Follow-Up
It is good medical practice for all women to have annual history and physical examinations, including women using oral contraceptives. The physical examination, however, may be deferred until after initiation of oral contraceptives if requested by the woman and judged appropriate by the clinician. The physical examination should include special reference to blood pressure, breasts, abdomen and pelvic organs, including cervical cytology, and relevant laboratory tests. In case of undiagnosed, persistent or recurrent abnormal vaginal bleeding, appropriate measures should be conducted to rule out malignancy. Women with a strong family history of breast cancer or who have breast nodules should be monitored with particular care.
2. Lipid Disorders
Women who are being treated for hyperlipidemias should be followed closely if they elect to use oral contraceptives. Some progestogens may elevate LDL levels and may render the control of hyperlipidemias more difficult.
3. Liver Function
If jaundice develops in any woman receiving such drugs, the medication should be discontinued. Steroid hormones may be poorly metabolized in patients with impaired liver function.
4. Fluid Retention
Oral contraceptives may cause some degree of fluid retention. They should be prescribed with caution, and only with careful monitoring, in patients with conditions which might be aggravated by fluid retention.
5. Emotional Disorders
Women with a history of depression should be carefully observed and the drug discontinued if depression recurs to a serious degree.
6. Contact Lenses
Contact lens wearers who develop visual changes or changes in lens tolerance should be assessed by an ophthalmologist.
7. Drug Interactions
Reduced efficacy and increased incidence of breakthrough bleeding and menstrual irregularities have been associated with concomitant use of rifampin. A similar association, though less marked, has been suggested with barbiturates, phenylbutazone, phenytoin sodium, carbamazepine, and possibly with griseofulvin, ampicillin and tetracyclines.72
8. Interactions with Laboratory Tests
Certain endocrine and liver function tests and blood components may be affected by oral contraceptives:
a. Increased prothrombin and factors VII, VIII, IX, and X; decreased antithrombin 3; increased norepinephrine-induced platelet aggregability.
b. Increased thyroid binding globulin (TBG) leading to increased circulating total thyroid hormone, as measured by protein-bound iodine (PBI), T4 by column or by radioimmunoassay. Free T3 resin uptake is decreased, reflecting the elevated TBG, free T4 concentration is unaltered.
c. Other binding proteins may be elevated in serum.
d. Sex hormone binding globulins are increased and result in elevated levels of total circulating sex steroids; however, free or biologically active level
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