PEBC: What You Need to Know: Combined Oral Contraceptives

Indications: contraception, acne, dysmenorrhea, irregular menses, menopausal bleeding

Combined oral contraceptives contain ethinyl estradiol (estrogen) plus a progestin

The progestin can vary:

1st generation: norethindrone

2nd generation: levonorgestrel

3rd generation: desogestrel, norgestimate

4th generation: drospirenone (anti-androgen properties)

Absolute Contraindications:

-history of venous thromboembolism

-uncontrolled hypertension > 160/100 mmHg

-uncontrolled diabetes (with microvascular complications)

-stroke

-smoker over 35 years old with more than 15 cigarettes a day

-within 6 weeks of postpartum

-breast cancer

-pregnancy

-undiagnosed vaginal bleeding

-migraine with aura

-liver tumour

Dosing:

-Once daily at the same time each day

-For 28-day pack, take continuously

-For 21-day pack, patient will have 7 day pill-free interval before starting next pack

Adverse Effects:

*Severe but rare:

-deep vein thrombosis/pulmonary embolism

-stroke

-breast cancer

-myocardial infarction

*Common:

-nausea and vomiting - take with food

-breast tenderness (estrogen)

-mood swings, water retention (progestin)

-spotting during first few months

-headache

Drug Interactions:

-Combined oral contraceptives (COC) may increase lamotrigine levels

-Antibiotics: theoretical concern as this may reduce COC concentrations due to reduced enterohepatic circulation. The only antibiotics proven to affect COC are rifampin and griseofulvin.

-Antiepileptics such as carbamazepine and phenytoin - may reduce COC levels - better to choose other contraceptives