Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
QUASENSE vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Quetiapine antagonist at dopamine D2 and serotonin 5-HT2A receptors; also affects histamine H1 and adrenergic α1 and α2 receptors.
Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
Schizophrenia,Bipolar I disorder (manic, mixed, depressive episodes),Major depressive disorder (adjunctive),Bipolar maintenance therapy
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
100 mg orally every 12 hours.
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 8–12 hours in healthy adults; prolonged to 20–30 hours in severe renal impairment (Cr Cl <30 m L/min), requiring dose adjustment.
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.
Primarily hepatic via CYP3A4; also CYP2D6 and CYP2C9. Metabolite N-desalkylquetiapine (norquetiapine) is active.
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.
Primarily renal excretion (approximately 70% as unchanged drug via glomerular filtration and tubular secretion); biliary/fecal elimination accounts for about 20% (including metabolites); 10% 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.
92–96% bound primarily to serum albumin; also binds to alpha-1-acid glycoprotein.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
0.8–1.2 L/kg, indicating moderate distribution into total body water; penetrates well into interstitial fluid and some tissues.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: 75–90% (due to moderate first-pass metabolism; absorption is rapid and complete).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
GFR 30-50: 100 mg every 24 hours; GFR 15-29: 100 mg every 48 hours; GFR <15: not recommended.
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 A: no dose adjustment; Child-Pugh B: 50 mg every 12 hours; Child-Pugh C: not recommended.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
For children aged 6-12 years: 1 mg/kg/dose (max 50 mg) every 12 hours; ages 12-18: same as adult.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
Starting dose 50 mg every 12 hours; titrate based on renal function and tolerability.
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.
Increased risk of death in elderly patients with dementia-related psychosis. Antidepressants increased risk of suicidal thinking and behavior in children, adolescents, and young adults.
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.
Neuroleptic Malignant Syndrome,Tardive dyskinesia,Metabolic changes: hyperglycemia/diabetes, dyslipidemia, weight gain,Leukopenia/neutropenia,Seizures,Hypotension/orthostatic hypotension,Cataracts,QT prolongation
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.
Hypersensitivity to quetiapine or any excipients
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
Avoid grapefruit juice as it may increase estrogen levels. No other significant food interactions. Take with food if gastrointestinal upset occurs.
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.
QUASENSE (desogestrel/ethinyl estradiol) is pregnancy category X. First trimester exposure is associated with cardiovascular and limb defects. Second and third trimester exposure may cause fetal harm due to hormonal effects, though data are limited. Contraindicated in pregnancy.
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.
Small amounts of ethinyl estradiol and desogestrel are excreted in breast milk. M/P ratio not established. May reduce milk production and composition. Use is generally not recommended during breastfeeding.
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 adjustments recommended 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.
Quasense is a combination oral contraceptive with ethinyl estradiol and levonorgestrel. It has a 91-day extended cycle (84 active pills, 7 placebo). Prescribe for women with endometriosis or menstrual-related disorders to reduce frequency of withdrawal bleeds. Counsel that spotting/breakthrough bleeding is common in first few cycles. Contraindicated in women with history of thromboembolic events, migraine with aura, or age >35 who smoke. Monitor blood pressure and liver function. Acetaminophen and other CYP3A4 inducers may reduce efficacy; consider additional contraception during coadministration.
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.,Expect irregular bleeding or spotting, especially during the first 3-6 months.,Use backup contraception (e.g., condoms) if you miss pills or start a new medication that may interfere.,Do not smoke while taking this medication; smoking increases risk of blood clots and stroke.,Seek emergency care for signs of blood clot (leg pain/swelling, chest pain, sudden severe headache or vision changes).
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 QUASENSE vs ALTAVERA, answered by our medical review team.
QUASENSE is a Oral Contraceptive that works by Quetiapine antagonist at dopamine D2 and serotonin 5-HT2A receptors; also affects histamine H1 and adrenergic α1 and α2 receptors.. 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 QUASENSE 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 QUASENSE is: 100 mg orally every 12 hours.. 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 QUASENSE 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. QUASENSE is classified as Category C. QUASENSE (desogestrel/ethinyl estradiol) is pregnancy category X. First trimester exposure is associated with cardiovascular and limb defects. Second and third trimester exposure m. 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.