Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
QUARTETTE vs AFIRMELLE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination oral contraceptive containing drospirenone, ethinyl estradiol, levomefolate calcium, and metformin. Drospirenone is a progestin with antimineralocorticoid and antiandrogenic activity. Ethinyl estradiol is an estrogen. Levomefolate calcium is a folate supplement. Metformin is a biguanide that decreases hepatic glucose production and improves insulin sensitivity.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial receptivity.
FDA-approved for the prevention of pregnancy in women with type 2 diabetes mellitus or at risk for type 2 diabetes,Off-label: Management of polycystic ovary syndrome (PCOS), acne vulgaris, hirsutism, and menstrual irregularities
Prevention of pregnancy (FDA-approved)
3 mg orally once daily for 21 days followed by 7 days of placebo.
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
Terminal elimination half-life is 12-14 hours; clinically this supports once-daily dosing with steady state achieved within 2-3 days.
Terminal elimination half-life: 12–15 hours. Steady-state achieved within 5 days with Q12H dosing.
Drospirenone: CYP3A4-mediated metabolism; ethinyl estradiol: primarily CYP3A4; metformin: not metabolized (excreted unchanged in urine); levomefolate calcium: converted to active folate via dihydrofolate reductase and other enzymes.
Ethinyl estradiol undergoes first-pass metabolism in gut and liver via CYP3A4, with conjugation to sulfate and glucuronide. Levonorgestrel is metabolized primarily by CYP3A4 to reduced and hydroxylated metabolites, then conjugated.
Renal excretion accounts for 55% (primarily as unchanged drug), biliary/fecal excretion 35%, and the remainder undergoes metabolic clearance.
Renal: 50% as unchanged drug and metabolites; fecal: 40% as metabolites; biliary: ~10% as glucuronide conjugates.
92% bound to albumin and alpha-1-acid glycoprotein.
~99% bound to serum albumin and sex hormone-binding globulin.
Vd = 0.8-1.0 L/kg, indicating extensive tissue distribution (total body water plus some tissue binding).
2.8 L/kg (apparent Vd), indicating extensive tissue distribution.
Oral: 80-90% (first-pass metabolism minimal); intravenous: 100%.
Oral: ~70% due to first-pass metabolism.
No dose adjustment required for mild to moderate renal impairment. Not recommended for severe renal impairment (Cr Cl <30 m L/min) or end-stage renal disease.
No dose adjustment required for mild to moderate renal impairment. Not recommended for use in end-stage renal disease.
Child-Pugh Class A or B: No adjustment. Child-Pugh Class C: Contraindicated.
Contraindicated in acute hepatic disease or severe (Child-Pugh C) hepatic impairment. Use with caution in mild to moderate hepatic impairment; monitor liver function.
Not established for patients under 18 years of age.
Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily) based on adult clinical trials.
No specific dose adjustment recommended. Use with caution due to potential for decreased renal function.
Not indicated for use in postmenopausal women; no specific dose adjustment required in healthy elderly, but limited data available.
Warning: Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. Women who use combination hormonal contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (especially in women over 35) and with heavy smoking (15+ cigarettes/day). Women who use combination hormonal contraceptives should be strongly advised not to smoke.
Risk of thromboembolic disorders, especially in smokers and women over 35; lactic acidosis associated with metformin, especially in renal impairment; hyperkalemia due to drospirenone's antimineralocorticoid effect; vitamin B12 deficiency with long-term metformin use; and folate supplementation risks in patients with vitamin B12 deficiency.
Thrombotic disorders (venous thromboembolism, stroke, myocardial infarction),Cigarette smoking (increases cardiovascular risk),Hypertension (especially in women with renal disease or migraines),Gallbladder disease,Hepatic neoplasia (benign and malignant),Carbohydrate and lipid metabolism effects,Ocular lesions (retinal thrombosis),Depressed mood or depression,Uterine bleeding irregularities,Reduced efficacy with hepatic enzyme inducers
Concomitant use with hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir with or without dasabuvir; renal impairment (Cr Cl <60 m L/min for metformin); acute or chronic metabolic acidosis including diabetic ketoacidosis; liver disease or tumors; history of or current thromboembolic disorders; known or suspected pregnancy; undiagnosed abnormal uterine bleeding; hypersensitivity to any component.
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast cancer, endometrial cancer, or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior oral contraceptive use,Hepatic adenoma or carcinoma (current or history),Known or suspected pregnancy,Hypersensitivity to any component of the product,Heavy smoking (≥15 cigarettes/day) in women over 35
No specific dietary restrictions. Grapefruit juice may slightly increase estrogen levels but not clinically significant. Advise consistent intake to avoid absorption variability.
Grapefruit juice may increase ethinyl estradiol levels; avoid large quantities. No significant food restrictions. Administer with food if GI upset occurs.
QUARTETTE is a combined hormonal contraceptive pill. In early pregnancy, exposure does not increase risk of major malformations. No known risk in first trimester; contraindicated in pregnancy due to lack of need and potential hormonal effects. Second and third trimester exposure is not applicable as pregnancy excludes use; no fetal risks reported from accidental exposure.
Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: exposure associated with congenital anomalies (e.g., cardiovascular, neural tube defects). Second and third trimesters: increased risk of fetal growth restriction, preterm birth, and neonatal respiratory distress. Postnatal: possible long-term developmental effects.
Excreted into breast milk in small amounts. Estrogen may reduce milk production and composition; use postpartum only after established lactation (6+ weeks). M/P ratio not established. Use alternative contraception during breastfeeding if possible.
Contraindicated during breastfeeding. Small amounts of ethinyl estradiol and norethindrone are excreted in breast milk; M/P ratio not well defined. Potential for adverse effects on infant (e.g., jaundice, breast enlargement). May reduce milk production and quality.
Not applicable; drug is contraindicated in pregnancy. No dose adjustment exists as use is avoided.
Contraindicated in pregnancy; no dose adjustment recommended. If exposure occurs, immediate discontinuation is required. No pharmacokinetic data support safe use; avoid use entirely.
QUARTETTE is a combined hormonal contraceptive containing ethinyl estradiol and levonorgestrel, with a unique 4-day placebo phase (91-day cycle) to extend menstrual suppression. For patients with breakthrough bleeding, consider shorter placebo intervals or continuous use. Assess venous thromboembolism risk factors before prescribing, especially in smokers over 35. Counsel on delayed start if initiating after day 5 of menses.
Afirmelle (levonorgestrel/ethinyl estradiol) is a combined oral contraceptive. Counsel patients to take at the same time daily to maintain consistent hormone levels. Use back-up contraception if a dose is missed. Monitor for signs of thromboembolism, especially in smokers over 35. Advise that certain antibiotics (e.g., rifampin) and anticonvulsants (e.g., phenytoin) may reduce efficacy. Consider progestin-only pill if contraindications to estrogen exist.
Take one pill daily at the same time; missed pills increase pregnancy risk.,Use backup contraception (e.g., condoms) for the first 7 days if starting after day 5 of menses.,Expect lighter, less frequent periods; spotting may occur initially.,Do not skip the 4 placebo pills; they are reminder pills.
Take one pill at the same time every day, even if you don't have sex.,If you miss a pill, follow the instructions in the package insert or ask your healthcare provider.,Use a backup method (like condoms) if you start late or miss pills.,This medication does not protect against HIV or other sexually transmitted infections.,Common side effects include nausea, breast tenderness, and breakthrough bleeding.,Seek medical help if you have symptoms of a blood clot: sudden chest pain, leg swelling, or shortness of breath.,Smoking while on this pill increases your risk of serious cardiovascular events.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about QUARTETTE vs AFIRMELLE, answered by our medical review team.
QUARTETTE is a Oral Contraceptive that works by Combination oral contraceptive containing drospirenone, ethinyl estradiol, levomefolate calcium, and metformin. Drospirenone is a progestin with antimineralocorticoid and antiandrogenic activity. Ethinyl estradiol is an estrogen. Levomefolate calcium is a folate supplement. Metformin is a biguanide that decreases hepatic glucose production and improves insulin sensitivity.. AFIRMELLE is a Combined Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial receptivity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between QUARTETTE and AFIRMELLE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of QUARTETTE is: 3 mg orally once daily for 21 days followed by 7 days of placebo.. The standard adult dose of AFIRMELLE is: One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between QUARTETTE and AFIRMELLE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. QUARTETTE is classified as Category C. QUARTETTE is a combined hormonal contraceptive pill. In early pregnancy, exposure does not increase risk of major malformations. No known risk in first trimester; contraindicated i. AFIRMELLE is classified as Category C. Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: exposure associated with congenital anomalies (e.g., cardiovascular, neural tube defe. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.