Comparative Pharmacology
Head-to-head clinical analysis: TRI LO SPRINTEC versus TRI LO ESTARYLLA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRI LO SPRINTEC versus TRI LO ESTARYLLA.
TRI LO SPRINTEC vs TRI-LO-ESTARYLLA
Head-to-head clinical comparison of therapeutic indices and safety profiles.
Tri-Lo Sprintec is a combination oral contraceptive containing ethinyl estradiol and norgestimate. It inhibits ovulation by suppressing gonadotropin release (FSH and LH) from the pituitary, increases viscosity of cervical mucus, and alters endometrial receptivity.
Combination oral contraceptive containing ethinyl estradiol and norgestimate. Suppresses gonadotropin secretion, primarily FSH and LH, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial lining, reducing implantation likelihood.
Prevention of pregnancy
Prevention of pregnancyAcne vulgaris treatment in females ≥15 years who have reached menarche and desire contraception
One tablet (0.035 mg ethinyl estradiol + 0.180/0.215/0.250 mg norgestimate) orally once daily for 28-day cycle: active tablets on days 1-21, placebo on days 22-28.
One tablet (20 mcg ethinyl estradiol/0.1 mg levonorgestrel) orally once daily for 21 days, followed by 7 days of placebo.
None Documented
None Documented
Ethinyl estradiol: terminal half-life approximately 17 hours. Norelgestromin (active metabolite of norgestimate): terminal half-life approximately 28 hours. Clinical context: Ethinyl estradiol half-life supports once-daily dosing with steady-state reached within 7-14 days; norelgestromin half-life allows for sustained progestogenic effect.
Ethinyl estradiol: 19-24 hours (terminal); Norgestimate: active metabolite norelgestromin 28-38 hours; allows once-daily dosing.
Ethinyl estradiol is metabolized primarily via CYP3A4; norgestimate is rapidly metabolized to norelgestromin and subsequently to norgestrel, with further metabolism involving CYP3A4 and other CYP enzymes.
Ethinyl estradiol: metabolized primarily via CYP3A4, undergoes first-pass metabolism, conjugation to glucuronides and sulfates. Norgestimate: rapidly deacetylated to norgestrel (active metabolite), further hydroxylated and conjugated; metabolism involves CYP3A4 and other CYP enzymes.
Renal (approximately 50-60% as metabolites, with about 20% as unchanged ethinyl estradiol glucuronide and 40% as norgestimate metabolites). Fecal (approximately 30-40% as metabolites).
Renal: ~40% as metabolites; Fecal: ~30% as metabolites (including ethinyl estradiol conjugates); Biliary: ~20% (enterohepatic recirculation).
Ethinyl estradiol: approximately 97-98% bound to albumin, 2% free. Norelgestromin: approximately 99% bound to sex hormone-binding globulin (SHBG) and albumin.
Ethinyl estradiol: ~97-98% bound to albumin; Norgestimate/norelgestromin: ~99% bound to SHBG and albumin.
Ethinyl estradiol: Vd approximately 4-5 L/kg. Norelgestromin: Vd approximately 3-4 L/kg. Clinical meaning: indicates extensive distribution into tissues, not primarily confined to plasma volume.
Ethinyl estradiol: 1.5-3 L/kg; Norelgestromin: 2-4 L/kg; reflects extensive tissue distribution.
Oral: ethinyl estradiol bioavailability approximately 45% (first-pass effect); norgestimate prodrug converted to norelgestromin with systemic bioavailability of approximately 63%.
Oral: Ethinyl estradiol ~45% (first-pass metabolism); Norgestimate extensively metabolized to active norelgestromin (bioavailability not directly applicable).
No specific dosing adjustment required for renal impairment. Use caution in severe renal impairment due to potential fluid retention.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure.
Contraindicated in severe hepatic disease or hepatocellular carcinoma. For mild to moderate hepatic impairment (Child-Pugh A or B), use alternative contraception; no established dosing guidelines.
Contraindicated in patients with acute or chronic hepatic dysfunction, including Child-Pugh class A, B, or C, until liver function returns to normal.
Not indicated for use before menarche. Post-menarche: same dosing as adults (one tablet daily). Safety and efficacy established in females of reproductive age.
Not indicated for use in females before menarche. For postmenarcheal adolescents, same dosing as adults (one tablet daily for 21 days, then 7 days placebo).
Not indicated for postmenopausal women; no geriatric dosing established.
Not indicated for use in females after menopause.
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age and with heavy smoking (≥15 cigarettes per day) and is quite marked in women over 35 years of age. Women who use combination oral contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events (e.g., thromboembolism, stroke, myocardial infarction) from combination oral contraceptive use, especially in women >35 years who smoke. Concomitant smoking is contraindicated in women >35 years.
["Increased risk of thromboembolic disorders (e.g., venous thromboembolism, stroke, myocardial infarction)","Cigarette smoking increases risk of serious cardiovascular events","Increased risk of hepatic neoplasia (benign and malignant)","Elevated blood pressure","Gallbladder disease","Carbohydrate and lipid metabolic effects"]
["Thromboembolic disorders and cardiovascular risks including venous thromboembolism, arterial thromboembolism, stroke, myocardial infarction","Hepatic neoplasia: benign and malignant liver tumors reported","Gallbladder disease","Elevated blood pressure","Carbohydrate and lipid metabolism effects","Headache/migraine exacerbation","Bleeding irregularities including amenorrhea and breakthrough bleeding","Depression","Hereditary angioedema","Chloasma","Folate levels reduction","Potential for reduced contraceptive efficacy with hepatic enzyme inducers","Reduced efficacy and increased breakthrough bleeding with CYP3A4 inducers"]
["Known or suspected pregnancy","Current or history of thrombophlebitis or thromboembolic disorders","Cerebrovascular or coronary artery disease","Known or suspected breast cancer or other estrogen-sensitive neoplasia","Undiagnosed abnormal uterine bleeding","Benign or malignant liver tumor or active liver disease","Hypersensitivity to any component","Use of hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir with or without dasabuvir"]
["Current or past venous thromboembolism (e.g., deep vein thrombosis, pulmonary embolism)","Cerebrovascular or coronary artery disease (e.g., stroke, myocardial infarction)","Thrombogenic valvular or rhythm disorders (e.g., atrial fibrillation with thrombogenic risk)","Uncontrolled hypertension (sustained blood pressure ≥160/≥100 mmHg)","Diabetes with vascular involvement","Headaches with focal neurological symptoms or migraine with aura (any age) or migraine without aura if >35 years","Biliary tract disease (including cholestatic jaundice of pregnancy or prior pill use)","Liver tumors (benign or malignant), acute hepatitis, or severe cirrhosis","Known or suspected pregnancy","Hypersensitivity to any component","Carcinoma of the breast or endometrium or other estrogen-sensitive neoplasia","Undiagnosed abnormal uterine bleeding","Cigarette smoking in women >35 years","Use of Hepatitis C combination regimen containing ombitasvir/paritaprevir/ritonavir with or without dasabuvir"]
Data Pending Review
Data Pending Review
No significant food interactions. Grapefruit may slightly alter estrogen metabolism but clinically not significant. Maintain consistent dietary habits if constipating.
No specific food restrictions. Grapefruit juice may slightly increase estrogen levels but is not considered clinically significant. High-fat meals may delay absorption slightly but do not reduce efficacy.
FDA Category X. Use contraindicated in pregnancy due to risk of congenital anomalies, particularly cardiovascular and limb defects, from exposure during first trimester. Second and third trimester exposure associated with potential for fetal harm, including androgenization of female fetuses and liver adenoma. Discontinue promptly if pregnancy occurs.
FDA Pregnancy Category X. Contraindicated in pregnancy due to known teratogenic effects. First trimester: increased risk of cardiovascular defects, neural tube defects, and oral clefts. Second and third trimesters: potential for fetal harm including masculinization of female fetuses from progestins. Discontinue immediately if pregnancy occurs.
Enters breast milk in small amounts (M/P ratio not established). May reduce milk production and quality. Use caution in nursing mothers, especially during early postpartum period. Consider alternative contraception until weaning.
Contraindicated during lactation. Estrogens and progestins are excreted in breast milk in small amounts (M/P ratio unknown for triphasic regimen). May reduce milk production and infant exposure to steroids. Alternative contraception recommended.
Contraindicated in pregnancy; no dose adjustments recommended as use is precluded. If inadvertently used, discontinue immediately.
No dosing adjustments apply as drug is contraindicated in pregnancy. If pregnancy occurs, discontinue immediately. Do not use for any indication during confirmed pregnancy.
Category C
Category C
Tri-Lo Sprintec is a triphasic oral contraceptive with ethinyl estradiol and norgestimate. Monitor for thromboembolic events, especially in smokers over 35. Advise use of backup contraception if vomiting/diarrhea occurs. CYP3A4 inducers may reduce efficacy.
Tri-Lo-Estarylla is a triphasic oral contraceptive containing ethinyl estradiol and norgestimate. It is important to counsel patients about the increased risk of venous thromboembolism, especially in smokers over 35. The low estrogen dose (25 mcg) may be associated with breakthrough bleeding, which typically improves after 3-6 months. Efficacy relies on consistent daily intake; missing doses requires backup contraception per package instructions. Drug interactions with rifampin, certain anticonvulsants, and St. John's wort can reduce efficacy.
Take one tablet daily at the same time; missed doses increase pregnancy risk.Use backup contraception for 7 days after missing 2 or more pills.Report symptoms of blood clots: leg pain/swelling, chest pain, sudden shortness of breath.Avoid smoking while on this medication, especially if over 35.May cause irregular bleeding initially; contact provider if persistent.
Take one pill daily at the same time, following the order on the pack. Missed pills increase pregnancy risk; refer to package insert for missed dose instructions.Do not smoke while taking this medication, especially if over 35, due to increased risk of blood clots, stroke, or heart attack.Common side effects include nausea, headache, breast tenderness, and spotting. These often improve after a few months.Use backup contraception (e.g., condoms) if you miss pills, vomit within 4 hours of taking a pill, or start a new medication that may interact.Contact your healthcare provider immediately if you experience signs of a blood clot: leg pain/swelling, sudden shortness of breath, chest pain, or severe headache.This medication does not protect against HIV or other sexually transmitted infections.