Contraception – PEBC Exam Preparation
This chapter is designed to equip Pharmacists preparing for the Pharmacy Examining Board of Canada (PEBC) exams with the necessary knowledge to provide comprehensive contraceptive care. The content draws from clinical research studies and guidelines, ensuring pharmacists are well-prepared to address a diverse patient population. However, it is important to acknowledge that the information presented may primarily reflect studies conducted on populations that do not fully encompass the unique identities of all patients. As such, pharmacists are encouraged to explore additional resources, such as the World Professional Association for Transgender Health (WPATH) Standard of Care, to further enhance their practice and meet the specific needs of each individual.
Goals of Therapy
The primary objective in contraceptive care is to prevent pregnancy effectively. This goal is achieved by tailoring contraceptive methods to align with the patient’s unique characteristics, including lifestyle, age, reproductive history (parity), and future fertility intentions. Individualized care is paramount to ensuring both efficacy and patient satisfaction.
Essential Preliminary Assessments
Before initiating any contraceptive method, healthcare professionals must conduct thorough baseline assessments. These evaluations help to identify potential contraindications and select the most appropriate option for each patient. Key considerations include:
Medical History – Review chronic conditions (e.g., hypertension, migraines, depression) and current medications that may interact with contraceptive methods.
Pregnancy Test – Confirm the absence of pregnancy prior to contraceptive initiation.
Weight Assessment – Weight may influence the efficacy of certain contraceptives.
Blood Pressure Monitoring – Critical for patients considering combined hormonal contraceptives (CHCs) to reduce the risk of cardiovascular complications.
Pelvic Examination – A bimanual exam and cervical inspection are necessary for patients opting for intrauterine devices (IUDs), cervical caps, or diaphragms.
STI Screening – Screening for sexually transmitted infections is recommended before initiating intrauterine contraception.
Selecting the Appropriate Contraceptive Method
Patient assessment is foundational to contraceptive selection. Various factors influence this decision, including smoking status, age, body mass index (BMI), breastfeeding, and the likelihood of adherence. Additionally, the presence of chronic conditions (such as endometriosis, acne, or osteoporosis) and the use of enzyme-inducing medications can impact contraceptive effectiveness and safety.
Pharmacists must recognize that effective contraception plays a crucial role in reducing maternal and child mortality rates. As patient needs evolve over time, contraceptive methods must be reassessed periodically. For younger patients, preferred methods are those that are reversible, affordable, and associated with high safety profiles and low failure rates.
A wide range of contraceptive options is available, varying in delivery routes, dosages, regimens, and generic alternatives. The chosen method should enhance, rather than hinder, physiological processes such as vaginal lubrication, spontaneity, and sexual pleasure.
Pathophysiology of the Menstrual Cycle – PEBC Exam Preparation
The menstrual cycle consists of two key phases, each characterized by distinct hormonal activity and physiological changes. Below is a step-by-step breakdown of the process:
Phase 1: Follicular Phase (Preovulatory Phase)
Day 1 – Start of Menstruation:
The follicular phase begins on the first day of menstrual bleeding (menses).
Follicle-stimulating hormone (FSH) is released, stimulating the growth of multiple ovarian follicles.
Day 7 – Follicle Selection:
By day 7, one follicle becomes dominant while the others regress.
The dominant follicle continues to grow, increasing estrogen production.
Endometrial Thickening:
Rising estrogen levels promote the thickening of the endometrial lining, preparing it for potential implantation.
Formation of LH Receptors:
The dominant follicle develops luteinizing hormone (LH) receptors in response to estrogen.
LH Surge (Midcycle):
High estrogen levels trigger the pituitary gland to release a surge of LH.
This surge leads to final follicle maturation and ovulation (release of the ovum into the fallopian tube).
Phase 2: Luteal Phase (Postovulatory Phase)
Ovulation – Start of Luteal Phase:
Ovulation marks the beginning of the luteal phase.
The ruptured follicle transforms into the corpus luteum.
Hormone Secretion by Corpus Luteum:
The corpus luteum secretes estrogen and large amounts of progesterone.
Progesterone prepares the endometrium for possible implantation by inducing secretory changes.
If Fertilization Occurs:
The corpus luteum continues to produce hormones, supporting early pregnancy.
If Fertilization Does Not Occur:
The corpus luteum degenerates, causing estrogen and progesterone levels to fall.
This hormone drop leads to menstruation, marking the start of a new cycle.
Consistency of Phases
Luteal Phase Duration: Typically lasts 14 ± 2 days.
Follicular Phase Variability: The length can vary, making ovulation timing unpredictable.
Cycle Length: The average menstrual cycle is 28 days, though cycles can range from 25 to 35 days.
Monitoring Physical Changes
Basal Body Temperature:
Stable during the follicular phase.
Drops slightly 12–24 hours before ovulation, then rises due to progesterone.
Three consecutive days of elevated temperature indicate ovulation has occurred.
Cervical Mucus:
After Menstruation: Minimal, opaque, sticky.
Approaching Ovulation: Increased volume, clear, thin, stretchable (resembling egg whites), facilitating sperm movement.
After Ovulation: Mucus becomes opaque and thick again until menstruation.
Fertility Window
Viability of Sperm: Up to 5 days within the reproductive tract.
Ovule Survival: 12–24 hours after ovulation.
Fertile Period: From 5 days before ovulation to 1 day after.
Peak Fertility: 2 days prior to ovulation.
Pregnancy Prevention: Effective contraceptive use is essential during this window if pregnancy is not desired.
Emergency Postcoital Contraception
Emergency contraception (EC) is a critical option to prevent unintended pregnancy after unprotected intercourse or contraceptive failure. The following outlines key emergency contraceptive methods available in Canada.
1. Levonorgestrel
Overview:
A single 1.5 mg dose of levonorgestrel taken within 24 hours of unprotected intercourse prevents approximately 95% of expected pregnancies.
Effectiveness decreases with delayed treatment, but it remains an option up to 5 days after intercourse.
Usage:
Levonorgestrel is effective after contraceptive method failures (e.g., condom breakage, missed pills).
It is less effective for individuals with higher body weight (≥80 kg), though it can still provide benefits. Health Canada recommends continued use until further evidence clarifies this concern.
Safety:
Levonorgestrel has a strong safety record with no major associated risks (e.g., deep vein thrombosis).
Side effects may include nausea, dizziness, vomiting, and fatigue.
Special Considerations:
Patients taking enzyme-inducing medications may require alternative EC methods, such as the copper IUD.
Backup contraception is recommended for the first 7 days after initiating hormonal contraception following levonorgestrel use.
2. Ulipristal Acetate
Overview:
Ulipristal acetate (30 mg) is a selective progesterone receptor modulator approved in Canada for pregnancy prevention within 120 hours (5 days) of unprotected intercourse.
It works by delaying ovulation or inhibiting ovulation altogether.
Effectiveness:
Ulipristal may be more effective than levonorgestrel when taken between 72 to 120 hours after intercourse.
Efficacy can decrease for individuals with a body mass index (BMI) ≥ 25 kg/m², but the European Medicines Agency (EMA) recommends continued use for all patients, as benefits outweigh potential risks.
Usage and Safety:
Ulipristal is the preferred option for patients with a BMI over 25.
Side effects may include nausea, headache, dysmenorrhea, abdominal pain, dizziness, and fatigue.
Hormonal contraception can be initiated 5 days after ulipristal use, with backup contraception recommended for the following 7 days.
3. Copper IUD
Overview:
The copper IUD is the most effective emergency contraception method, preventing pregnancy if inserted within 7 days of unprotected intercourse.
It can be retained for long-term contraception, providing ongoing pregnancy prevention.
Advantages:
The copper IUD is non-hormonal, making it an excellent option for patients who cannot use hormonal contraception.
It remains the only method that provides continuous contraception after emergency use.
Safety and Efficacy:
Meta-analyses demonstrate a failure rate of only 0.1%, making the copper IUD highly effective.
Insertion should be preceded by ruling out existing pregnancy.
Nonpharmacologic Choices
Pharmacologic Options for Contraception – PEBC Exam Preparation
Combined Estrogen and Progestin Contraceptives
Overview of Combined Oral Contraceptives (COCs):
Combined oral contraceptives (COCs), containing both synthetic estrogen and progestin, are among the most widely used contraceptive methods in Canada. Male condoms are also commonly used, providing additional protection against sexually transmitted infections (STIs). COCs have undergone modifications to enhance potency, resulting in lower doses, improved safety, and reduced side effects.
🚩Absolute Contraindications to COCs🚩
Before prescribing COCs, it is essential to consider contraindications that could pose significant health risks. Table 1 outlines the conditions in which COCs should be avoided:
Hormone-Dependent Conditions:
Breast cancer or hormone-sensitive cancers
Cardiovascular and Vascular Disorders:
History of cerebrovascular accident or stroke
Complicated valvular heart disease
Current or previous venous thromboembolism, pulmonary embolism, or thrombogenic mutations (e.g., factor V Leiden, protein S, protein C deficiency)
Myocardial infarction or ischemic heart disease
Uncontrolled hypertension
Metabolic and Chronic Conditions:
Diabetes with vascular complications
Severe cirrhosis or liver tumors
Pregnancy and Postpartum:
Current pregnancy
Less than 6 weeks postpartum while breastfeeding
Neurological Disorders:
Migraines with aura (regardless of age)
Lifestyle and Smoking:
Smoking in individuals over 35 years (≥15 cigarettes/day)
Efficacy and Advantages of COCs:
Research shows no significant difference in the effectiveness or bleeding patterns between monophasic and triphasic COCs. Monophasic COCs, which have a fixed hormone dose, are often easier to manage.
Low-Dose COCs:
COCs containing 20-25 mcg of ethinyl estradiol (EE) effectively prevent pregnancy, with rates between 0.07 and 2.1 pregnancies per 100 patient-years in individuals aged 18 to 35.
Ultra-low-dose COCs, such as those with 10 mcg of EE (e.g., Lolo), are also available for individuals seeking lower hormone exposure.
Low-dose COCs are associated with reduced bloating and breast tenderness but may increase the likelihood of bleeding irregularities.
Cycle and Dosing Variations:
Most COCs follow a 28-day cycle with 21 days of active pills and a 7-day hormone-free interval. Some regimens extend beyond 21 days to reduce hormone-free days.
Products like Yaz and Lolo offer regimens with extended active pill days.
For cycles exceeding 28 days, extended or continuous use of COCs can be considered.
Progestin Variations in COCs:
Progestin formulations differ, influencing side effects and therapeutic benefits.
Third-Generation Progestins:
Desogestrel and norgestimate have lower androgenic effects, making them beneficial for managing acne.
Cyproterone acetate (not approved for contraception by Health Canada) is used in acne treatment due to its antiandrogenic properties.
Drospirenone (Aldosterone Antagonist):
Drospirenone-containing COCs exhibit antimineralocorticoid and antiandrogenic effects.
A Cochrane review suggests these COCs may alleviate symptoms of premenstrual dysphoric disorder (PMDD). However, the benefits for mild cases or prolonged use beyond three cycles remain inconclusive.
Observational studies indicate that drospirenone COCs carry a higher venous thromboembolism risk than other progestins.
Hormonal Activity of COC Products
Key Considerations for COC Selection
Drug Interactions: COCs are metabolized in the liver by CYP3A4 enzymes. Efficacy may decrease in patients taking enzyme-inducing drugs (e.g., antiepileptics such as carbamazepine, oxcarbazepine, and rifampin). These medications accelerate estrogen metabolism, reducing contraceptive effectiveness.
Recommendations for Patients on Enzyme-Inducing Drugs:
Choose non-hormonal options (e.g., copper IUD, barrier methods) or depot medroxyprogesterone acetate.
Alternatively, patients on short-term enzyme inducers can take 1 COC pill daily (at least 30 mcg EE) continuously for 3-4 cycles without a hormone-free interval, followed by a 4-day break.
Patients using enzyme-inducing medications long-term may use two COCs containing 20-35 mcg EE with a 4-day hormone-free interval.
Rifampin and rifabutin require alternative non-COC contraceptive methods.
Contraceptive Vaginal Ring
The estrogen/progestin-releasing vaginal ring (NuvaRing) offers consistent hormone delivery throughout the day, minimizing hormonal fluctuations. This method bypasses hepatic first-pass metabolism and gastrointestinal absorption, allowing for lower hormone doses. The contraceptive efficacy of the vaginal ring is comparable to that of low-dose combined oral contraceptives (COCs).
Key Points:
Irregular bleeding occurs in 5.5% of users, while 9.8% experience withdrawal bleeding.
Failure rate: 0.65 pregnancies per 100 patient-years.
The ring can be used continuously, avoiding interference with intercourse.
A randomized controlled trial (RCT) comparing 28-day cycles with continuous ring use indicated similar side effects (breast tenderness, mood changes, weight fluctuations).
Continuous use led to a slight increase in bleeding days (3.5%) and spotting (7.1%), prompting some users to discontinue the method.
Transdermal Contraceptives
The transdermal contraceptive patch (Evra) offers comparable contraceptive efficacy to COCs, with higher adherence rates (88% vs. 78%). The patch provides consistent ovulation suppression.
Effectiveness:
Pregnancy rate: 0.70 to 0.88 pregnancies per 100 patient-years.
The patch may be less effective in individuals weighing over 90 kg.
Obesity can reduce follicular development despite high hormone levels.
Extended or Continuous Use of Combined Hormonal Contraceptives
Continuous or extended use of combined hormonal contraceptives (CHCs) – including pills, patches, and rings – eliminates the hormone-free interval, reducing symptoms such as dysmenorrhea, heavy menstrual flow, or social discomfort. This can be achieved through marketed products (e.g., extended-cycle tablets) or by adjusting traditional cycles.
Benefits of Continuous Use:
Reduces side effects (pelvic pain, headaches, bloating, swelling).
Can improve symptoms of endometriosis and polycystic ovary syndrome (PCOS).
May reduce pregnancy rates compared to standard 28-day cycles.
One disadvantage includes the potential for unscheduled bleeding.
Amenorrhea may raise concerns about potential pregnancy.
Risks:
A cohort study indicated a slight increase in venous thromboembolism (VTE) with continuous CHC use compared to cyclic use, but the difference was not clinically significant.
Progestin-Only Contraceptives
Oral Progestin
Norethindrone-only pills prevent pregnancy by thickening cervical mucus, which inhibits sperm penetration. Regular and timely use is critical, as cervical mucus thins approximately 22 hours post-dose.
Guidelines:
Backup contraception is recommended for the first month, though some experts suggest 2 days may suffice.
Suitable for individuals over 35 who smoke or experience COC side effects.
Effective for migraine sufferers or breastfeeding individuals.
Drospirenone-only pills were introduced in Canada in May 2022, offering reliable ovulation suppression.
Unlike norethindrone, drospirenone exhibits antimineralocorticoid activity, increasing hyperkalemia risk.
Depot Medroxyprogesterone Acetate (DMPA)
The injectable contraceptive DMPA suppresses ovulation, but users may experience irregular bleeding, weight gain, mood swings, and bloating. This method is particularly useful for patients over 35 who smoke or cannot tolerate estrogen.
Key Considerations:
Failure rate: <0.32% per year.
Menstrual periods may not resume for up to 12 months post-injection.
Bone mineral density (BMD) studies show a 7.2% loss in patients aged 18-54 compared to non-users.
Higher risk of BMD loss in those starting DMPA before 21 or using it for over 15 years.
No conclusive evidence links DMPA to osteoporosis or fractures.
Etonogestrel Implant
Introduced in Canada in 2020, the single-rod etonogestrel (ENG) implant continuously releases progestin over 3 years, suppressing ovulation.
Benefits:
Highly effective with a failure rate of 0.05%.
Fertility returns shortly after removal.
May aid in managing heavy periods, dysmenorrhea, and endometriosis.
Adverse Effects:
Irregular bleeding, weight gain, acne, headaches, emotional lability, and breast tenderness.
Insertion/removal complications may occur.
Levonorgestrel Intrauterine System (IUS)
The LNG-IUS releases low levels of progestin directly into the uterus, effectively preventing pregnancy (failure rate: 0.2% for 52 mg devices over 5 years). This system lowers menstrual bleeding by 90% and alleviates conditions like fibroids, dysmenorrhea, and endometriosis.
Advantages:
Suitable for patients at risk of heavy bleeding or those seeking long-term contraception.
Reduces invasive cervical cancer risk by 40%.
Insertion and Safety:
Expulsion rates are higher in younger patients.
Perforation, infection, and expulsion rates are similar across age groups.
Misoprostol is not necessary before insertion.
Pain Management:
NSAIDs (e.g., naproxen 500 mg BID for 5-7 days) and tranexamic acid can reduce post-insertion bleeding.
Risks Associated with Hormonal Contraception – PEBC Exam Preparation
Hormonal contraceptives (HC) may pose increased risks for certain health conditions, such as myocardial infarction (MI), stroke, venous thromboembolism (VTE), and breast cancer. However, the overall benefits of contraception often outweigh these risks, as pregnancy itself carries a higher morbidity and mortality risk. For example, while COCs may raise the risk of VTE by 1.5 to 3 times, pregnancy is associated with a 6-fold increase in VTE risk.
Pharmacists should individualize contraceptive choices by assessing the patient’s medical history, risk factors (e.g., smoking, hypertension, obesity), and the non-contraceptive benefits of hormonal methods. The following table summarizes key risks associated with HC and corresponding management strategies.
Risks and Management of Hormonal Contraceptives
Abbreviations:
COC – Combined Oral Contraceptive
CHC – Combined Hormonal Contraceptive
LNG-IUS – Levonorgestrel Intrauterine System
VTE – Venous Thromboembolism
CI – Confidence Interval
CV – Cardiovascular
Management of Adverse Effects of Hormonal Contraceptives – PEBC Exam Preparation
Adverse effects associated with hormonal contraceptives (HCs), such as nausea, headache, and breakthrough bleeding, typically decrease within 3 to 6 months of continued use. However, these side effects can significantly impact adherence and satisfaction with contraceptive methods. Proper assessment of their severity and duration is crucial before switching to alternative methods.
The following table outlines common adverse effects of hormonal contraceptives and practical management strategies.
Management of Adverse Effects of Hormonal Contraceptives
Abbreviations:
COC – Combined Oral Contraceptive
DMPA – Depot Medroxyprogesterone Acetate
ENG – Etonogestrel
LNG-IUS – Levonorgestrel Intrauterine System
EE – Ethinyl Estradiol
Cu-IUD – Copper Intrauterine Device
HC – Hormonal Contraceptive
STI – Sexually Transmitted Infection
HIV and Contraception
Barrier Protection:
The most effective method to reduce the risk of HIV transmission is the correct and consistent use of latex male condoms. Regardless of formulation or dosage, spermicides containing nonoxynol-9 do not protect against HIV.
Intrauterine Devices (IUDs) and HIV:
Copper IUDs do not increase the risk of acquiring HIV in non-contraceptive users. However, there is theoretical concern regarding pelvic infections in patients with HIV/AIDS who use IUDs. Evidence supporting this concern is limited.
Progestin IUDs may interact with viral shedding, but current data does not strongly support this risk.
General Recommendations:
Individuals at risk of HIV should consistently use latex condoms during sexual activity, regardless of additional contraceptive methods.
No evidence conclusively shows that hormonal contraceptives (e.g., COCs) increase HIV risk in individuals who are HIV-negative or enhance disease progression in HIV-positive individuals.
Antiretroviral drugs may interact with COCs, though no significant correlation has been found between COC use and changes in CD4 counts or RNA levels.
Contraceptive Choices during Breastfeeding and Postpartum Period
Fertility and Contraception After Delivery
Fertility restoration is unpredictable in breastfeeding individuals, with ovulation and potential pregnancy possible within six weeks of delivery. At the postpartum visit, pregnancy should be excluded if intercourse has occurred before six weeks postpartum. Initiation of hormonal contraception should follow confirmation that the patient is not already pregnant.
Contraceptive Choices in the Postpartum Period
Barrier Methods and Spermicides:
Barrier methods and spermicides offer lubrication for the hypoestrogenic vagina and can provide contraception, although they may be less effective compared to other methods.
Progestin-Only Contraceptives:
Progestin-only contraceptives (excluding drospirenone-containing products) are recommended for postpartum patients, regardless of breastfeeding status.
These methods are safe during breastfeeding, with a lower risk of thrombosis in the initial six weeks postpartum compared to combined oral contraceptives (COCs).
Norethindrone formulations must be taken consistently at the same time daily to avoid missed pills, breakthrough bleeding, and reduced contraceptive efficacy.
COCs may be introduced at three weeks postpartum in non-breastfeeding individuals, while those at higher risk of venous thromboembolism (VTE) should avoid COCs for at least six weeks.
Intrauterine Devices (IUDs):
Levonorgestrel-releasing intrauterine systems (LNG-IUS) can be inserted immediately after delivery (vaginal or cesarean) or following abortion (first or second trimester).
Immediate insertion is safe and effective, providing postpartum contraceptive assurance.
Immediate placement minimizes the risk of unintended pregnancies and abortions.
Good uterine fundal placement is essential to reduce expulsion risk.
Contraceptive Choices and Breastfeeding
Progestin-Only Methods:
Current evidence suggests that progestin-only contraceptives do not negatively impact infant growth, development, or health.
COC Considerations:
Use of COCs within the first six weeks postpartum may increase the risk of thrombotic events and potentially reduce milk supply.
After six weeks, evidence of COC impact on breastfeeding success is inconsistent, and later initiation (>6 weeks) is not associated with adverse infant outcomes.
Emergency Contraception (EC):
Levonorgestrel (1.5 mg) can be used between 24 to 72 hours postpartum for emergency contraception without affecting breastfeeding.
Ulipristal acetate, if used for EC, may require the patient to avoid breastfeeding for at least 24 hours. WHO recommends avoiding breastfeeding for one week after ulipristal intake. Breast milk should be expressed and discarded during this time.
How to Manage Missed Dose