What are the guidelines for prescribing oral contraceptives?

Guidelines for Prescribing Oral Contraceptives

For healthy women with no contraindications, initiate a combined oral contraceptive containing 20-30 μg ethinyl estradiol with levonorgestrel or norethisterone, taken daily for 21 days followed by 7 hormone-free days. 1

Pre-Prescription Screening and Contraindications

Before prescribing oral contraceptives, assess for absolute contraindications using the WHO Medical Eligibility Criteria (Category 4 conditions where contraceptive use represents unacceptable health risk): 2

Absolute Contraindications (Do Not Prescribe):

• Current pregnancy 2
• Age ≥35 years AND heavy smoking (≥15 cigarettes/day) 2, 3
• Hypertension with systolic ≥160 mm Hg or diastolic ≥100 mm Hg 2
• History of or current deep vein thrombosis or pulmonary embolism 2
• Ischemic heart disease (history or current) 2
• History of cerebrovascular accident 2
• Migraine with focal neurologic symptoms at any age, or migraine without aura if age ≥35 years 2
• Current breast cancer 2
• Active viral hepatitis, severe decompensated cirrhosis, or liver tumor 2
• Diabetes with end-organ damage or ≥20 years duration 2
• Breastfeeding <6 weeks postpartum 2

Relative Contraindications (Category 3 - risks usually outweigh benefits):

• Age ≥35 years with light smoking (<15 cigarettes/day) 2
• Hypertension: systolic 140-159 mm Hg or diastolic 90-99 mm Hg 2
• Breastfeeding 6 weeks to <6 months postpartum 2
• History of breast cancer with ≥5 years of no disease 2

Recommended Initial Formulations

First-line choice: Combined oral contraceptive with 20-30 μg ethinyl estradiol plus levonorgestrel or norethisterone 1

The estrogen dose directly correlates with stroke risk - for every 10 μg increase in ethinyl estradiol, there is a 19% increased odds of stroke (OR 1.19,95% CI 1.16-1.23) 2. Lower doses of ethinyl estradiol are mandatory to minimize stroke risk. 2

FDA-approved formulations for acne treatment (if this is a concurrent indication): 2

• Ethinyl estradiol/norgestimate
• Ethinyl estradiol/norethindrone acetate/ferrous fumarate
• Ethinyl estradiol/drospirenone
• Ethinyl estradiol/drospirenone/levomefolate

Special Population Considerations

For women with specific stroke risk factors (age >35 years, tobacco use, hypertension, or migraine with aura): 2

• Progestin-only contraception or non-hormonal methods are preferred to avoid estrogen-related stroke risk 2
• If combined hormonal contraceptives are chosen after shared decision-making, use the lowest possible estrogen dose 2

For postpartum women not breastfeeding: 3

• May initiate 4 weeks postpartum
• Must consider increased thromboembolic risk in postpartum period 3
• Use backup contraception until white (active) tablets taken for 7 consecutive days 3

For women with premature ovarian insufficiency requiring contraception: 2

• First choice: 17β-estradiol-based combined oral contraceptives with nomegestrol acetate or dienogest
• Second choice: ethinyl estradiol-based combined oral contraceptives

Dosing Instructions and Initiation

Sunday Start Method: 3

• Begin first white tablet on first Sunday after menstruation begins
• Use backup contraception for first 7 consecutive days 3
• Take 1 white tablet daily for 21 days, followed by 2 light-green inert tablets, then 5 light-blue tablets 3

Day 1 Start Method: 3

• Begin first white tablet on first day of menstruation
• Take 1 white tablet daily for 21 days, followed by 2 inert tablets, then 5 ethinyl estradiol tablets 3

Missed Pill Management Protocol

One pill late (<24 hours): 2, 1, 3

• Take the late pill immediately
• Continue regular schedule (may take 2 pills same day)
• No backup contraception needed
• Emergency contraception not needed

One pill missed (24-48 hours late): 2, 1, 3

• Take most recent missed pill immediately (discard other missed pills)
• Continue regular schedule
• Use backup contraception (condoms) or avoid intercourse for 7 consecutive days 2, 1

Two or more consecutive pills missed (≥48 hours late): 2, 1, 3

• Take most recent missed pill immediately (discard other missed pills)
• Continue taking remaining pills at usual time
• Use backup contraception for 7 consecutive days 2, 1
• If pills missed in Week 1 AND unprotected intercourse occurred in previous 5 days, consider emergency contraception 2
• If pills missed in Week 3 (days 15-21): omit hormone-free interval by starting new pack immediately 2

Important Clinical Considerations

Higher-dose pills (30 μg) provide better ovulation suppression than 20 μg formulations when pills are missed 2, 1, though this must be balanced against increased stroke risk with higher estrogen doses 2.

Breakthrough bleeding is the most common reason for discontinuation 4. Breakthrough bleeding is highest during first few cycles and typically decreases thereafter 5. Switching from brand-name to therapeutically equivalent formulations may increase breakthrough bleeding and ultimately lead to unintended pregnancy 4.

Monitoring requirements: 1

• Blood pressure should be monitored during routine follow-up visits
• No routine follow-up visits are required, but women should return for side effects or method change 1

Common pitfalls to avoid:

• Do not prescribe combined hormonal contraceptives to women with migraine with aura at any age 2
• Do not use formulations containing >30 μg ethinyl estradiol as initial therapy 1
• Do not substitute therapeutically equivalent products without counseling about potential increased breakthrough bleeding 4
• Recognize that smoking substantially increases cardiovascular risk, particularly in women >35 years 3

Contraceptive effectiveness: The Pearl index for low-dose ethinyl estradiol/levonorgestrel 20 μg/100 μg is 0.88 pregnancies per 100 woman-years with perfect use 5, though typical use failure rates range from <3% to 5% due to compliance issues 6.