Yaz
Yaz
Generic Name
Yaz
Mechanism
- Ovulation suppression – Drospirenone antagonizes LH and FSH surge, preventing follicular rupture.
- Cervical mucus thickening – Both hormones increase viscosity, impeding sperm penetration.
- Endometrial inhibition – Estrogen stabilizes the endometrium, while drospirenone reduces glandular proliferation.
- Anti‑androgenic activity – Drospirenone blocks androgen receptors, decreasing sebum production and acne lesions.
- Anti‑mineralocorticoid effect – Weakly antagonizes aldosterone, modestly reducing fluid retention.
These actions collectively prevent pregnancy and provide therapeutic benefits for androgen‑related dermatoses and menstrual disorders.
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Pharmacokinetics
| Parameter | Value | Notes |
| Absorption | Rapid, peak plasma 2–3 h post‑dose | Food does not significantly alter Cmax |
| Bioavailability | ~30–50 % (first‑pass hepatic metabolism) | Drospirenone > 80 % oral bioavailability |
| Metabolism | CYP3A4‑mediated → 4‑hydroxy‑drospirenone, ethinyl‑estradiol glucuronides | Enzyme inducers decrease efficacy |
| Half‑life | Drospirenone 19 h | Estradiol 2–3 h |
| Protein binding | Drospirenone 98 % | Estradiol 98 % |
| Excretion | Hepatic ↑ fecal bile; renal ~5 % unchanged | Reduced in hepatic impairment |
| Drug interactions | CYP3A4 inducers (e.g., rifampin, carbamazepine, St. John’s wort) ↑ clearance → ↓ contraceptive efficacy; CYP3A4 inhibitors may ↑ drospirenone levels → ↑ adverse events |
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Indications
- Primary infertility prevention: effective birth‑control method for women <45 y.
- Acne vulgaris: improves lesions via anti‑androgenic action.
- Menstrual disorders: reduces dysmenorrhea and heavy menstrual bleeding.
- PMDD: alleviates affective and somatic symptoms.
- Polycystic ovary syndrome (PCOS): controls ovulation and may improve menstrual regularity.
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Contraindications
| Category | Key Points |
| Absolute Contraindications | |
| • Pregnancy or suspected pregnancy | |
| • History of thromboembolic disease (DVT/PE) | |
| • Breast‑feeding (risk of breast abscesses) | |
| • Known estrogen‑sensitive malignancy (e.g., breast cancer) | |
| • Recent (160 mmHg or DBP >100 mmHg) | |
| Relative Contraindications | • Smoking ≥15 cigarettes/day in women >35 y; <35 y if no risk factors. |
| Warnings | • VTE risk (≈3–5 per 10,000 woman‑years). Monitor for leg pain, swelling, chest pain. |
| • Hemorrhagic stroke (especially in hypertensive patients). | |
| • Hepatic dysfunction: monitor LFTs; avoid in severe disease. | |
| • Breast pain/abscesses: avoid during lactation. |
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Dosing
| Cycle | Schedule | Notes |
| Standard 24/4 | 21 pills + 4 placebo (skip) | Take tablets every day at the same time. |
| 24th pill: start next pack day 5 | Optional 1‑day gap (day 0 placebo) for young patients. | |
| 7‑day hormone‑free interval | May reduce breakthrough bleeding. | |
| Start |
• Day 1 of menses (preferred) • Alternatively start on any day if 21‑day pack used, but risk of breakthrough bleeding ↑. | |
| Missed Dose |
• <12 h: take as soon as remembered; no condom needed. • 12–24 h: take immediately; use barrier method 72 h. • >24 h: take as soon as remembered, use backup contraception 72 h. | |
| Pregnancy Test | Do not initiate if positive; obtain baseline test. | |
| Breastfeeding | Contraindicated; switch to non‑hormonal contraception. |
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Adverse Effects
- Common (≤10 %)
- Nausea, vomiting
- Breast tenderness, acne flare‑back
- Headache, dizziness
- Menstrual spotting or breakthrough bleeding
- Increased libido or mood swings
- Serious (≤1 %)
- Venous thromboembolism (DVT/PE)
- Ischemic stroke or myocardial infarction
- Severe hypertension or hypertensive crisis
- Hepatic adenoma/carcinoma
- Severe allergic reactions (rare)
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Monitoring
| Parameter | Frequency | Rationale |
| Blood pressure | Every visit, at least annually | Detect hyper‑aldosteronism‑induced edema, VTE risk |
| Weight | At each visit | Monitor fluid retention, metabolic changes |
| Liver function tests | Baseline + annually | Detect hepatotoxicity |
| Pregnancy test | If bleeding occurs, or if patient reports unprotected sex | Ensure ongoing efficacy |
| VTE risk assessment | Baseline, + if family history or new risk factor | Guide contraceptive choice |
| Skin/Mucosal evaluations | On suspicion of acne flare or rash | Adjust therapy if necessary |
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Clinical Pearls
- Start with a 21‑day pack if your patient has a history of irregular cycles; transition to 24/4 later.
- Use of drospirenone’s anti‑mineralocorticoid effect can modestly aid in fluid‑retained states; consider when prescribing to women with mild edema.
- Pregnancy test should be performed prior to the first dose *even if the patient is menstruating* to avoid inadvertent exposure.
- CYP3A4 inducers (e.g., rifampin, carbamazepine) *halve Yaz’s efficacy*; prescribe alternative contraception in such patients.
- Adolescents with severe acne can benefit from adding a short‑term topical retinoid adjunct while on Yaz to maximize dermatologic outcomes.
- Risk stratify for VTE: A patient aged 35+ who smokes >15 cigarettes/d and has hypertension should receive a non‑hormonal option or a low‑estrogen OCP.
- Use of aspirin 81 mg daily may further reduce VTE risk in high‑risk patients, but weigh hemorrhagic stroke risk.
- For breakthrough bleeding on day 5–7 after starting a pack, reassure the patient; most cases resolve within 2‑3 days; consider adding a short course of low‑dose progesterone if persistent.
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• Key Takeaway:
*Yaz* is a low‑dose estrogen COC highly effective for contraception and dermatologic benefits, but its thromboembolic and hepatic safety profile demands careful patient selection, lifestyle assessment, and routine monitoring.