What are the contraindications and side effects of progestin-only pills (POP), particularly in women with a history of breast cancer, liver disease, unexplained vaginal bleeding, blood clots, stroke, or heart attack?

Contraindications and Side Effects of Progestin-Only Pills

Progestin-only pills have very few absolute contraindications compared to combined hormonal contraceptives, with only 1.6% of reproductive-aged women having any contraindication to their use. 1

Absolute Contraindications (Category 4 - Do Not Use)

According to the FDA label and CDC guidelines, POPs are absolutely contraindicated in the following conditions:

• Known or suspected pregnancy 2
• Known or suspected carcinoma of the breast (current breast cancer) 2, 3
• Undiagnosed abnormal genital bleeding 2
• Hypersensitivity to any component of the product 2
• Benign or malignant liver tumors 2
• Acute liver disease 2

Conditions Requiring Caution (Category 3 - Risks Usually Outweigh Benefits)

The following conditions are classified as Category 3, meaning POPs should generally not be used unless other methods are unavailable or unacceptable:

• Severe (decompensated) cirrhosis - due to impaired hepatic metabolism of hormonal contraceptives 4
• Hepatocellular adenoma 4
• Malignant liver tumors (hepatoma) 4
• Seizure disorder treated with topiramate or other enzyme-inducing anticonvulsants - these medications significantly reduce POP effectiveness through hepatic enzyme induction 4
• Rifampicin or rifabutin therapy - similar mechanism to enzyme-inducing anticonvulsants 4
• Systemic lupus erythematosus with positive or unknown antiphospholipid antibodies 4, 3
• Past breast cancer with no evidence of disease for 5 years 4
• Uncontrolled hypertension (systolic ≥160 mm Hg or diastolic ≥100 mm Hg) 3

Conditions Requiring Some Caution (Category 2)

• History of deep vein thrombosis or pulmonary embolism - POPs carry substantially less thrombotic risk than combined oral contraceptives 3
• History of stroke 3
• Multiple cardiovascular risk factors (older age, smoking, diabetes, hypertension combined) 3
• History of ectopic pregnancy 3
• Severe thrombocytopenia - concern is increased bleeding risk, not thrombosis 5

Common Side Effects

The most frequently reported adverse effects of POPs include:

Menstrual Changes (Most Common)

• Irregular bleeding patterns - the most commonly reported complaint with all POPs 6, 7
• Breakthrough bleeding 3
• Amenorrhea 3
• Menorrhagia 3
• Spotting 3

Central Nervous System

• Headache 3
• Depression 3
• Nervousness 3
• Mood changes 3

Endocrine/Reproductive

• Breast pain or tenderness 3
• Weight changes 3

Gastrointestinal

• Abdominal pain 3
• Nausea 3
• Vomiting 3
• Diarrhea 3

Genitourinary

• Urinary tract infections 3
• Vaginitis 3
• Vaginal candidiasis 3

Other

• Viral infections 3
• Sinusitis 3

Important Clinical Considerations

Cardiovascular Safety

• POPs do not increase risk of myocardial infarction or stroke in otherwise healthy women - with relative risks of 0.98 (95% CI 0.66-1.47) for MI and 1.02 (95% CI 0.72-1.44) for stroke 3
• Women with history of cardiovascular disease can generally use POPs (Category 2), unlike combined hormonal contraceptives which are contraindicated 3

Special Populations Where POPs Are Preferred

• Breastfeeding women - POPs can be initiated immediately postpartum without concerns about milk production 3
• Women with contraindications to estrogen - including migraine with aura, history of VTE, smoking over age 35 6
• Postpartum period - can be started at any time, including <21 days postpartum 3

Efficacy Concerns

• Enzyme-inducing medications significantly reduce POP effectiveness - women on long-term anticonvulsants should use alternative contraception or DMPA instead 4
• Strict adherence required - POPs must be taken at the same time daily for maximum effectiveness 6
• Pregnancy rates range from 1.4 to 4.3 per 100 woman-years, though rates approaching combined oral contraceptives have been reported with good counseling 8

Counseling Priorities

• Menstrual irregularities are expected and not harmful - proactive counseling about variable bleeding patterns improves compliance and continuation 6, 7
• No routine screening required before initiation - pelvic examination, breast examination, and laboratory tests are not necessary for safe POP initiation 3
• Pregnancy testing recommended if pregnancy status is uncertain 3