Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
QUARTETTE vs ALTAVERA
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 of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
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,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
3 mg orally once daily for 21 days followed by 7 days of placebo.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Terminal elimination half-life is 12-14 hours; clinically this supports once-daily dosing with steady state achieved within 2-3 days.
Levonorgestrel: terminal elimination half-life 25±10 hours; ethinyl estradiol: 13±7 hours. Clinical context: steady-state concentrations achieved within 5-7 days; contraceptive efficacy requires consistent daily 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: primarily metabolized by CYP3A4; undergoes sulfation and glucuronidation. Desogestrel: rapidly converted to active metabolite etonogestrel via CYP2C9 and CYP2C19; further metabolism by CYP3A4.
Renal excretion accounts for 55% (primarily as unchanged drug), biliary/fecal excretion 35%, and the remainder undergoes metabolic clearance.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
92% bound to albumin and alpha-1-acid glycoprotein.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Vd = 0.8-1.0 L/kg, indicating extensive tissue distribution (total body water plus some tissue binding).
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: 80-90% (first-pass metabolism minimal); intravenous: 100%.
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic 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. Contraindicated in severe renal disease or acute renal failure due to potential fluid retention.
Child-Pugh Class A or B: No adjustment. Child-Pugh Class C: Contraindicated.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Not established for patients under 18 years of age.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
No specific dose adjustment recommended. Use with caution due to potential for decreased renal function.
Not indicated for postmenopausal women. No specific geriatric dosing; consider increased risk of thromboembolism, cardiovascular disease, and metabolic effects in older women of reproductive age.
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 combined oral contraceptives. Risk increases with age (especially >35 years) and with number of cigarettes smoked. Women who use combined 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: risk of venous thromboembolism (VTE), stroke, myocardial infarction; discontinue if thrombotic event occurs.,Hepatic disease: discontinue if jaundice or liver function abnormalities develop.,Hypertension: monitor blood pressure; discontinue if uncontrolled.,Carbohydrate metabolism: may affect glucose tolerance; monitor diabetic patients.,Depression: discontinue if significant depression occurs.,Gallbladder disease: increased risk of cholelithiasis.
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 carcinoma,Estrogen-dependent neoplasia (known or suspected),Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma (known or suspected),Pregnancy (known or suspected),Hypersensitivity to any component
No specific dietary restrictions. Grapefruit juice may slightly increase estrogen levels but not clinically significant. Advise consistent intake to avoid absorption variability.
No significant food interactions. Alcohol does not affect efficacy but may increase risk of adverse effects such as nausea. Grapefruit juice has no known interaction. Avoid excessive alcohol consumption due to potential hepatotoxicity.
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.
ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular defects (relative risk 1.2-1.4) and no consistent increase in other major malformations. Second and third trimesters: No known teratogenic effects, but theoretical risks from estrogenic effects (e.g., feminization of male fetus). Postnatal: No increased risk of long-term developmental effects from pregnancy exposure.
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.
Combined oral contraceptives may reduce milk production and quality, especially in early lactation. Ethinyl estradiol transfers into breast milk at low levels (M/P ratio approximately 0.1-0.2), excluding clinical effects in term infants. Levonorgestrel transfer is minimal (M/P ratio ~0.2-0.4). Use is generally avoided in breastfeeding women, especially during the first 6 weeks postpartum. Progestin-only methods are preferred.
Not applicable; drug is contraindicated in pregnancy. No dose adjustment exists as use is avoided.
Contraindicated in pregnancy. No dose adjustment recommended because use is discontinued upon confirmed or suspected pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased hepatic clearance, altered binding proteins) are not relevant for this indication.
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.
ALTAVERA is a combined oral contraceptive (COC) containing ethinylestradiol and levonorgestrel. It inhibits ovulation via suppression of gonadotropins. Counsel patients to take at the same time daily to maintain efficacy. Missed pill management: if missed within 12 hours, take immediately; if >12 hours, take last missed pill and use backup contraception for 7 days. Be aware of increased VTE risk, especially in smokers over 35. May reduce effectiveness of lamotrigine; monitor seizure control. Initiate on the first day of menses or first Sunday after onset.
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 tablet daily at the same time each day, with or without food.,If you miss a pill by less than 12 hours, take it as soon as you remember. If more than 12 hours, take the missed pill and use a backup method (e.g., condoms) for the next 7 days.,Smoking increases your risk of serious cardiovascular side effects, especially if you are over 35 years old. Do not smoke while taking this medication.,Seek immediate medical attention if you experience sudden severe headache, chest pain, leg pain/swelling, or vision changes (symptoms of blood clots).,This medication does not protect against HIV or other sexually transmitted infections.,If you are taking lamotrigine or other anticonvulsants, tell your doctor; your seizure medication may be less effective.,Store at room temperature away from moisture and heat.
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 ALTAVERA, 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.. ALTAVERA is a Combined Oral Contraceptive that works by Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between QUARTETTE and ALTAVERA 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 ALTAVERA is: 1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.. 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 ALTAVERA 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. ALTAVERA is classified as Category C. ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular def. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.