Endocrine Drugs · Contraceptives
The facts most likely to be tested
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Combined oral contraceptives (COCs) function primarily by inhibiting the mid-cycle LH surge, thereby preventing ovulation.
The estrogen component of COCs increases the risk of venous thromboembolism (VTE) by inducing a hypercoagulable state through increased hepatic production of clotting factors.
COCs are strictly contraindicated in women over 35 years old who smoke due to the significantly elevated risk of myocardial infarction and ischemic stroke.
COCs provide a protective effect against endometrial cancer and ovarian cancer by suppressing ovulation and thinning the endometrial lining.
Patients with a history of migraine with aura should not use COCs because of the increased risk of ischemic stroke.
COCs are a first-line treatment for polycystic ovary syndrome (PCOS) to regulate menses and reduce androgen levels by increasing sex hormone-binding globulin (SHBG).
COCs are contraindicated in patients with a history of estrogen-dependent tumors (e.g., breast cancer) or active liver disease.
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A 36-year-old female presents to the clinic requesting a prescription for oral contraceptives. She has a past medical history of polycystic ovary syndrome and currently smokes 15 cigarettes per day. Her blood pressure is 128/82 mmHg, and her BMI is 29 kg/m². She has no history of VTE, migraines, or malignancy. She is eager to start a method that will help regulate her cycles.
Which of the following is the most appropriate contraceptive recommendation for this patient?
Progestin-only pill or intrauterine device (IUD)
This question tests the contraindication of COCs in patients over 35 who smoke; because the patient is 36 and a smoker, estrogen-containing contraceptives are contraindicated due to the high risk of cardiovascular events.
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High yield triage
Classification
Synthetic estrogen and progestin combination.
Indications
Contraception, dysmenorrhea, acne vulgaris, and PCOS.
Mechanism of Action
Suppresses GnRH release, inhibiting LH/FSH surge and ovulation.
Side Effects
Nausea, breast tenderness, thromboembolism, hypertension.
Contraindications / Monitoring
History of DVT/PE, smokers >35, migraine with aura. Monitor blood pressure.
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Mechanism of Action
Synthetic estrogen inhibits FSH secretion, preventing follicular development. Progestin inhibits the LH surge, preventing ovulation. Additionally, progestin thickens cervical mucus to impede sperm transport and thins the endometrium to prevent implantation.
Unique Properties
COCs provide non-contraceptive benefits including reduced risk of ovarian cancer and endometrial cancer. Certain formulations containing drospirenone have anti-androgenic properties, making them preferred for androgen excess states like acne.
Indications
Primary use is contraception. Frequently prescribed for dysmenorrhea, menorrhagia, and cycle regulation in PCOS. Also used to manage endometriosis-associated pain.
Pharmacokinetics
Metabolized primarily via the hepatic cytochrome P450 system. Inducers (e.g., rifampin, phenytoin, carbamazepine) decrease efficacy by increasing metabolism, requiring backup contraception.
Side Effects & Adverse Events
Breakthrough bleeding is the most common reason for discontinuation. Venous thromboembolism risk is dose-dependent on estrogen. Hypertension may occur due to increased angiotensinogen production. Breast cancer risk is slightly elevated during use.
Contraindications
History of DVT/PE or thrombophilia due to hypercoagulability. Smokers >35 due to synergistic myocardial infarction risk. Migraine with aura due to increased ischemic stroke risk. Uncontrolled hypertension (>160/100 mmHg).
Monitoring
Baseline and periodic blood pressure checks are mandatory. No routine laboratory monitoring is required for healthy patients. Assess for red-flag symptoms of ACHES (Abdominal pain, Chest pain, Headaches, Eye problems, Severe leg pain).
Clinical Pearls
Always screen for migraine with aura; if present, COCs are contraindicated due to stroke risk. If a patient misses a dose, advise taking the missed pill as soon as remembered. COCs are the gold standard for managing PCOS-related hyperandrogenism.