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Combined OC (Drospirenone / Ethinyl Estradiol)

Hormonal Contraceptiveprescriptionoral · inferred

Combined OC with drospirenone (anti-androgenic progestin, t1/2 ~31h) and ethinyl estradiol. Brands: Yaz, Yasmin, Beyaz. Drospirenone has mild diuretic and anti-androgenic properties. Unique among OCs for potassium-sparing effect.

Projected serum levels — 1 pill (≈ 3.0 mg), once daily

Combined OC (Drospirenone / Ethinyl Estradiol)
Combined OC (Drospirenone / Ethinyl Estradiol) modeled serum levels, 1 pill (≈ 3.0 mg) once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 0.50 1 1.5 2 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1

Maintenance schedule: 1 pill (≈ 3.0 mg) once daily (oral).

Modeled steady state after ~1 days: peak ≈ 1.1 mg, trough ≈ 0.059 mg body load. Population-based estimate over 15 days for a reference dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Hormonal Contraceptive
Route modeled
Oral
Model confidence
inferred
Half-life
4.9 h
Common dose
1 pill (≈ 3.0 mg)
Suggested maximum
1 pill/day
Reference dose range
0.50–1 pill (single dose)
Suggested cadence
once daily

Documented interactions

  • danger
    Carbamazepine (Tegretol) + Combined OC (Drospirenone / Ethinyl Estradiol) CYP induction

    Carbamazepine (Tegretol) inducer of CYP3A4 predicted to change Combined OC (Drospirenone / Ethinyl Estradiol) AUC by ~0.31x

  • danger
    Drospirenone + Combined OC (Drospirenone / Ethinyl Estradiol) Stacked effects

    Combined OC (Drospirenone / Ethinyl Estradiol) and Drospirenone both push the androgen receptor, mineralocorticoid receptor, and progesterone receptor in the same direction.

  • danger
    Efavirenz (Sustiva) + Combined OC (Drospirenone / Ethinyl Estradiol) CYP induction

    Efavirenz (Sustiva) inducer of CYP3A4 predicted to change Combined OC (Drospirenone / Ethinyl Estradiol) AUC by ~0.21x

  • danger
    Nicotine + Combined OC (Drospirenone / Ethinyl Estradiol) Contraindicated

    Smoking while on combined OCs dramatically increases cardiovascular risk.

  • danger
    Phenobarbital + Combined OC (Drospirenone / Ethinyl Estradiol) Depletion

    Phenobarbital induces CYP3A4 and UGT1A1, reducing ethinyl estradiol and drospirenone levels. Contraceptive failure is a well-documented clinical risk.

  • danger
    Phenytoin (Dilantin) + Combined OC (Drospirenone / Ethinyl Estradiol) CYP induction

    Phenytoin (Dilantin) inducer of CYP3A4 predicted to change Combined OC (Drospirenone / Ethinyl Estradiol) AUC by ~0.48x

Serum checks 117 modeled interaction pairings for combined oc (drospirenone / ethinyl estradiol) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Pharmacokinetics of Drospirenone and Ethinylestradiol Including Effects on Aldosterone and SHBG Krattenmacher R · Contraception, 2000 DOI

    Comprehensive pharmacology of drospirenone: anti-mineralocorticoid (natriuretic), anti-androgenic, with 76% bioavailability and 31h elimination half-life.

  2. Drospirenone: Pharmacology and Pharmacokinetics of a Unique Progestogen Sitruk-Ware R · Contraception, 2005 DOI

    Review establishing drospirenone as pharmacologically closest to natural progesterone among synthetic progestins, with unique antimineralocorticoid activity.

  3. Risk of Venous Thromboembolism Among Users of Drospirenone-Containing Oral Contraceptive Pills Jick SS, Hernandez RK · Contraception, 2011 DOI

    Case-control study finding drospirenone OCs carry approximately 2-3x higher VTE risk compared to levonorgestrel OCs, informing risk-benefit counseling.

3 published studies referenced in the app, each with a plain-language summary.