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By Kathleen Hill-Besinque, Pharm.D., M.S.Ed. |
Contraception choices are both personal decisions and public health issues. The personal aspects include issues related to sexuality, family plans, religious or cultural beliefs, medical conditions, and individual preferences. Public health issues include increases or decreases in the relative risk for cancers, medical complications of contraception and childbearing, and abortion rates. Although the availability, safety, and efficacy of contraceptive methods have been improved significantly over the past fifty years, the rate of unplanned pregnancies in the United States remains among the highest in developed countries.' An estimated fifty percent of all pregnancies in the United States are unplanned, and it is estimated that half of the unplanned pregnancies are aborted. Teen pregnancy contributes significantly to the unintended pregnancy rate in the United States. Unintended pregnancy rates are also high in women who are 40-44 years old, indicating a need for more contraceptive options for older women.
Misconceptions regarding contraceptive methods are common. A 1993 Galiup poll found that 65% of women believed that oral contraceptives were at least as risky as pregnancy. Actually, the risk of death from pregnancy is more than five times the risk of death resulting from oral contraceptive use in nonsmoking women. In fact, no contraceptive method carries more risk to women than pregnancy and childbirth. In the same survey, 58% of respondents were unable to name one noncontraceptive benefit of oral contraceptives. The survey found that 29% of women believed that oral contraceptives cause cancer, and 31 % believed the contraceptive failure rate to be at least 10%. The same survey found that only 6% of respondents thought protection from some cancers resulted from oral contraceptives.2
Actually, there are several noncontraceptive benefits from oral contraceptives including protection from ovarian and endometrial cancer. Despite educational programs, the prevalence of misconceptions regarding the risks and benefits of contraception remains high.
Pharmacists are in an ideal position to educate women about contraception and help them with contraceptive choices. Patient counseling and education improve contraceptive efficacy and patient satisfaction with contraceptive choices. Contraceptives, when used incorrectly, may result in an unplanned pregnancy or unwanted side effects. Side effects are a significant cause of non-compliance with contraceptive methods and discontinuation of use. Women may have fears about a method or questions about the printed information provided with oral contraceptives. The pharmacist is more accessible char other medical providers and is usually the provider of contraceptive products. Strategies to cope with side effects may improve compliance and continuation. Instructions regarding initiation of the regimens, missed pills, and back-up contraception can be provided when contraceptives are dispensed. In addition to prescription products, several contraceptive products are available over the counter. Patients using barrier methods of contraception such as diaphragms or condoms may be offered information about emergency contraceptive options. Questions regarding safety, techniques for proper use, and the efficacy of nonprescription products can be answered by the pharmacist.
Many factors are considered in the selection of a contraceptive method. Patient concerns regarding the safety and efficacy of a method are important determinants. Other factors include the desire for future pregnancy, age of the patient, experience with contraceptives in the past, the need for protection from sexually transmitted diseases, cultural and religious beliefs, partner cooperation, ability of the patient to properly use the method, and cost. Factors in the selection of a contraceptive also include medical conditions or contraindications to hormonal contraception, the potential for drug interactions, the need for episodic versus continual protection from pregnancy, and noncontraceptive benefits. Noncontraceptive benefits are becoming increasingly important in the selection of contraceptive methods. Factors important to the selection of contraceptive methods change over time. Women should be offered opportunities to reassess their contraceptive choices throughout their reproductive lives.
Approximately half of all unplanned pregnancies occur in women using contraception." All methods of contraception have an inherent failure rate. Contraceptive failure may occur because the method was not effective (method failure), because the patient did not use the method or did not use it properly (user failure), or as a result of interfering factors such as drug interactions. The efficacy of contraceptive methods is evaluated on the basis of perfect use and typical use data. Perfect use is derived from clinical trials in which highly motivated patients are using the method correctly and with complete compliance. Failure rates for perfect use are generally lower than rates reported during typical use. Typical use is the failure rate reported by actual patients under everyday circumstances.
Another important factor related to contraceptive failure is the continuation rate for contraceptive methods. A continuation rate is the percentage of users still using a method after one year. Continuation rates are influenced by contraceptive failure (pregnant patients no longer require contraception) and by patient dissatisfaction with the method. The most common reason for discontinuation of hormonal contraceptives is the occurrence of side effects (particularly breakthrough bleeding). Table 1 lists the typical use and perfect use failure rates, and continuation rates for contraceptive methods currently available in the United States.
Since the discovery that hormones control and regulate the menstrual cycle in the 1930s, researchers have worked to develop hormonal products that control fertility. Hormonal methods of contraception are safe, reversible, provide noncontraceptive benefits to users (and past users), and are highly effective. Contraindications to the use of hormonal agents include current thromboembolic disorders and a history of hormone-sensitive tumors. The package inserts contain patient contraindications for use.
Hormonal contraceptive formulations include a progestin, with or without an estrogen. Progestin's are the predominant pharmacologically active component of all hormonal methods. Progestin's inhibit ovulation by inhibiting luteinizing hormone which produces changes in cervical mucus that are hostile to sperm, and by altering the endometrium, which makes implantation unlikely.4 The estrogen component serves to stabilize the endometrium (which prevents irregular bleeding), suppress ovulation by inhibiting follicle stimulating hormone, and potentiate the effects of progestin.
Estrogen-related side effects include nausea, breast tenderness, fluid retention, and cyclic weight changes. Estrogens may also have adverse effects on the coagulation system which are related to thromboembolic complications. "Progestin related side effects include weight gain, acne, depression, and possibly changes in the lipid profile. Progestins may also produce a thinning of the endometrium, which results in scanty withdrawal bleeding or amenorrhea.
| Table 1: Effectiveness Use Rates in United States | ||||
|---|---|---|---|---|
| Method | Reversible (Y/N) | Effectiveness* Perfect Use |
Effectiveness* Typical Use |
Continuation Rates** |
| Sterilization | Not reliably | High | High | High |
| Norplant TM | Yes | High | High | High |
| Depo-Provera R TM | Yes | High | High | Moderate |
| Combination oral pills | Yes | High | High | Moderate |
| Progestin only pills | Yes | High | High | Moderate |
| Male condoms | Yes | High | Moderate | Moderate |
| Diaphragm | Yes | Moderate | Moderate | Moderate |
| Periodic Abstinence | Yes | Moderate | Low | Moderate |
| Spermicides | Yes | Moderate | Low | Low |
| No method | NA | Low | Low | Low |
|
* highly effective=less than 3% failure rate moderate continuation rate=50-80% continuation after 1 year low continuation rate=less than 50% continuation after 1 year |
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Oral contraceptives are the most widely utilized method of contraception in the United States. Oral contraceptives provide reliable, reversible, and easy-to-use contraception, with significant health benefits to users and relatively minor and uncommon side effects. Noncontraceptive health benefits include reduction in the risk of endometrial cancer and ovarian cancer, a reduced risk of ectopic pregnancy, improved cycle control, reduced anemia from heavy menses, a reduction in pelvic inflammatory disease, a decreased risk of rheumatoid arthritis, and increased bone density. Despite proven health benefits, many misconceptions and concerns regarding the safety and risks of oral contraceptives remain; education continues to be important in removing confusion and relieving concerns.
Combination oral contraceptives contain both an estrogen and a progestin and are prescribed for 21 consecutive days followed by a seven-day hormone free interval. Formulations can be monophasic, biphasic, or triphasic. Monophasic regimens provide fixed doses of estrogen and progestin for 21 days. Biphasic formulations provide a fixed estrogen dose and an increased dose of progestin for the last 11 days of the cycle. Triphasic formulations, which have been widely utilized over the past five years, provide increasing doses of progestin every seven days, and either a fixed or increasing dose of estrogen, throughout the cycle.
The initial oral contraceptive selected should be the lowest estrogen dose formulation which effectively prevents pregnancy. Nearly all of the products available today contain ethinyl estradiol as the estrogen component. In 1996, approximately 98% of all oral contraceptive prescriptions were for products containing 3 5 mcg or less of estrogen. An increase in spotting or breakthrough bleeding may occur with lower dose formulations, usually during the first three cycles of contraceptive use. Patients should be reassured that the bleeding is temporary and that spotting does not indicate decreased efficacy. An increased risk of thromboembolic complications corresponds with increased estrogen doses. Estrogen doses above 50 mcg of ethinyl estradiol induce changes in the coagulation and fibrolytic system. It is not clear if these changes occur with doses of 20 mcg ethinyl estradiol."" Currently, the recommended combination oral contraceptives are those containing 3 5 mcg of estrogen or less.
There are several progestins currently approved for use in oral contraceptives and more products are in development. Little conclusive evidence exists to demonstrate that any one progestin is more effective than the others. The newer or second generation progestins are reported to have beneficial effects on the blood lipid profile. The long term benefits of these lipid effects will not be known for several years. Patients who are sensitive to progestin may benefit from products with lower total progestin doses, including multiphasic preparations.
| Table 2: Missed Tablets | ||
|---|---|---|
| Number of tablets missed | Action by patient | Back-up contraception required |
| 1 | Take missed tables as soon as remembered. If not until the next day, take 2 tablets for one day only. | No (may be advised by some clinicians for 7 days) |
| 2 | Take 2 tablets as soon as remembered and take 2 tablets the next day. | Yes, for 7 days. |
| 3 | Begin a new cycle of pills using the instructions from the product insert (Sunday or first day of flow start). | Yes, until 7 days of therapy taken. |
| Figure 1: A.C.H.E.S. |
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Abdominal pain |
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Chest Pain |
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Headache |
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Eye or vision changes |
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Severe leg pain |
The risk of ovarian cancer in users and past users of combination oral contraceptives (COC) is reduced by approximately 40%. The protective effect from COC increases with increased duration of use, and is thought to result from inhibition of ovulation. Protection persists for as long as fifteen or more years after discontinuation of COC use. 10 A reduction in the incidence of endometrial cancer has also been reported in users and past users of COC. Women who used COC for at least 12 months have a reduction of 40% in the incidence of endometrial cancer. As with ovarian cancer, the protection persists for up to 15 years after discontinuing COC use. Pelvic inflammatory disease (PID) is a significant factor in infertility in the United States. The use of COC decreases the risk of hospitalization from PID significantly."
The incidence of breast cancer may be slightly increased in users of COC; however, this remains controversial. COC are protective against benign breast disease but not breast cancer. Data collection is still under way to better define the role of COC in breast cancer risk. Patients should be reassured that the increased risk of breast cancer from COC is small.' An increased risk of thromboembolism in users of COC was identified many years ago. The risk was associated with higher doses of estrogens, and identification of this risk contributed to the lowering of estrogen doses in COC. An increased risk of cervical cancer in COC users has also been reported which appears to be linked to the use of COC for six or more years. However, the increased risk is small, and the studies identifying this risk did not control adequately for variables such as smoking or multiple sexual partners, which are independent risk factors for cervical cancer. Women using COC should be advised to have regular PAP screening for cervical cancer.'
Acne is generally improved in women taking any formulation of COC, although some patients using androgenic progestins may experience an increase in acne. However, such increases are less common.
Patient counseling for women who use combination oral contraceptives is important both to clarify instructions for administration and to inform patients of side effects. A back-up method of contraception should be discussed and provided with the initial prescription. Instructions for missed pills should also be discussed (see Table 2). Common side effects, including nausea, spotting, and potentially serious effects (see ACHES, Figure 1) should be reviewed. Patients with nausea may find it helpful to take the dose at bedtime. Women should be reassured that nausea and spotting decrease considerably after the first 3 cycles of use. Because many women believe that a periodic rest from oral contraceptives is beneficial, they should be advised that there is no reason to discontinue COC for a rest Women who do discontinue oral contraceptives for a rest should be advised that substituting a less effective form of contraception may increase their risk for pregnancy. Again, education is a key to effective use of oral contraception.
Progestin-only oral contraceptives are an attractive option for women unable to tolerate estrogen and those who are breastfeeding. The efficacy of progestin-only pills is lower than that of combination oral contraceptives. Also, because of the relatively low doses of progestin-only pills, patients must strictly adhere to the daily regimen, taking the doses as close to every 24 hours as possible: patients who miss pills or take pills on an irregular schedule are more likely to ovulate and become pregnant.
The initial cycle of progestin-only pills should be started on the first day of menses. Patients should be instructed to take one pill every day continuously. There are no pill-free days in a progestin-only regimen.
Irregular bleeding is common in progestin-only pill regimens and is a major reason for discontinuation. Many women experience short, irregularly spaced cycles or amenorrhea, and they are often concerned about the possibility of pregnancy in the absence of regular cycles. It may be reassuring to the patient to keep home pregnancy tests available in the home.
Patient counseling for progestin-only oral contraceptives should include the importance of taking the pills at exactly the same time every day. Patients should be educated about the possibility of spotting and irregular menstrual cycles. Back-up contraceptive regimens should be discussed and a back-up contraceptive dispensed to the patient.
Introduced in 1992 in the United States, Depo-Provera™ (depomedroxyprogesterone acetate, DMPA) is a highly effective, long-acting progestin-only method of contraception. The efficacy of DMPA is high because, unlike other progestin-only methods of contraception, the dose of progestin is high enough to suppress ovulation reliably. The injection is effective for 12 weeks; therefore patient compliance is high.
DMPA injections should be initiated during menses or within the first five days of the cycle and repeated every 12 weeks. Contraceptive activity is immediate if given during menses, and no back-up method is required. If the first injection is not given within the first five days of the cycle, a pregnancy test should be done to exclude pregnancy and a back-up method used for the first two weeks.
Good candidates for DMPA include women who have difficulty complying with oral regimens, women seeking long-lasting contraception, women taking medication for seizure disorders, women intolerant of estrogens, breastfeeding women, and possibly women with a history of thromboembolism. Noncontraceptive benefits of DMPA include lack of an effect on lactation, decreased risk of endometrial cancer, reduced menstrual flow, reduced risk of PID, reduced risk of endometriosis, and fewer ectopic pregnancies.
Problems with DMPA include a high incidence of irregular bleeding and amenorrhea. However, irregular bleeding tends to stabilize with continued use, and many patients experience complete amenorrhea (80%) after one year. A delay of six to nine months in the return to fertility is possible following discontinuation of DMPA injections. A reduction in bone density has also been reported with the use of DMPA, but the reduction is mild and reversible upon discontinuation. Patient education should include information regarding irregular bleeding and me delay in return to fertility.
The Norplant™ contraceptive system consists of long-acting progestin (lev-onorgestrel) containing rods that are implanted subdermally. The Norplant™ system is highly effective, rapidly reversible, and provides protection against
pregnancy for five years. Levels of levonorgestrel are sufficient to prevent pregnancy within 24 hours of insertion and fall to ineffective levels within 24 hours of removal.
A significant number of patients using Norplant™ report menstrual irregularities. Irregular spotting and bleeding are common reasons for removal of Norplant systems within the first year of use. Bleeding irregularities tend to stabilize after the first year of use.
Good candidates for Norplant™ systems include breastfeeding women. women who have completed childbearing but do not want sterilization, women seeking long-term protection from pregnancy, women who cannot tolerate estrogens, and women who have difficulty complying with other methods of contraception. Patients who are properly educated about this method are more likely to be satisfied and experience safe, effective, long-lasting contraception.
The use of barrier methods for contraception dates from at least the earliest historical times of man. Currently, barrier methods of contraception are less popular than hormonal methods. The use of condoms for contraception has declined, but condom use for prevention of sexually transmitted diseases has increased dramatically in the last two decades and largely because of AIDS.
Barrier contraceptives mechanically block the access of sperm to the egg. Barrier methods are most effective when combined with a spermicidal agent. Unlike hormonal contraceptives, barrier methods are free of systemic effects. Barrier methods are temporary and used during or in anticipation of intercourse and require consent and proper use to insure efficacy.
Diaphragms are latex rubber devices inserted into the vagina and positioned over the cervical opening. Diaphragms must be fitted by a health care provider, and patients should be refitted after childbirth. A diaphragm can be inserted up to six hours before intercourse, but should not be removed until six hours after intercourse. Repeated sexual intercourse requires the application of additional spermicide to the vagina without removing the diaphragm. (However, some patients may experience a burning or irritation from the spermicide,) There may be an increase in urinary tract infections when using diaphragms, and to minimize the risk of urinary infections, women should be encouraged to void after intercourse. For recurrent cases, a post-coital antibiotic regimen may be prescribed.
Condoms are an inexpensive, temporary barrier contraceptive which may provide protection from some sexually transmitted diseases. The contraceptive efficacy of condoms varies significantly due to improper or inconsistent use and the quality of material used. Male condoms are more effective than the female condom. Male condoms are available in latex, polyurethane, and natural skin varieties. Latex and polyurethane condoms provide protection from some sexually transmitted diseases, while natural products do not. Male condoms may include a lubricant or a spermicide. The female condom is polvurethane and does not require application of a spermicide. Condoms are a good back-up method of contraception. Patients who use condoms for contraception should be counseled regarding proper use and receive information about post-coital contraception regimens in the event of breakage or noncompliance.
Spermicidal agents are available as creams, foams, jellies, films, and suppositories. The most common active ingredient is nonoxynol-9, which is thought to exert its contraceptive effect by destroying the cell wall of sperm. For optimal protection, Spermicidal agents must fully disperse in the vagina, cover the cervix, and be applied within the time guidelines provided in me product literature. Additional spermicide must be used for repeated sexual intercourse. Spermicidal agents are a readily available, inexpensive, reversible, nonprescription method of contraception. The efficacy is lower in comparison to hormonal products or barriers. The combination of a male condom and a Spermicidal agent may be equal to that of COC. Spermicides are a good choice for back-up contraception. Local irritation and allergic reactions may be experienced by either partner.
The future offers additional methods of contraceptive hormone delivery, including vaginal rings, better tolerated injections, biodegradable implants, and lower dose oral contraceptive formulations.
Contraceptive methods in the United States have improved in safety, efficacy, and variety over the past several decades. The variety of contraceptive choices has improved the quality of life for women. Patient education and counseling are essential to ensure the efficacy of currently available methods and to help patients select a method which best suits their needs. Pharmacists not only are able to provide the contraceptives, but are also in an ideal position to provide the education and support needed by patients who are making choices about contraceptive methods.
As the results of long-term studies which answer questions about the risk of breast cancer and the nonconcraceptive benefits of hormonal products become available, the best use of these products will become clearer. Improved availability of contraceptives and better patient education may result in a decrease in the unplanned pregnancy rate in the United States. Programs designed to reduce teenage pregnancy and increase contraceptive use in this age group may also reduce the rates of unplanned pregnancies.