ELINEST

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ELINEST (ELINEST).

How it works

Ethinyl estradiol is an estrogen; drospirenone is a progestin with anti-mineralocorticoid and anti-androgenic activity. The combination suppresses gonadotropins, inhibiting ovulation.

What the body does with it

Metabolism	Ethinyl estradiol is metabolized via CYP3A4 and undergoes conjugation; drospirenone is metabolized primarily via CYP3A4 to inactive metabolites.
Excretion	~68% renal (50% unchanged, ~18% as inactive metabolites), ~30% biliary/fecal, with enterohepatic recycling of drug and estrogen conjugates.
Half-life	Terminal elimination half-life of estradiol (E2) is ~13-16 h, but due to the prodrug nature and accumulation of estrogen metabolites, the effective half-life during continuous use is ~36 h, supporting once-daily dosing.
Protein binding	~98-99% bound, primarily to sex hormone-binding globulin (SHBG) and albumin, with ~45% bound to SHBG and remainder to albumin.
Volume of Distribution	Apparent Vd for estradiol is ~0.6-0.7 L/kg, reflecting distribution into total body water and some tissue binding (e.g., fat and reproductive tissues).
Bioavailability	Oral: ~5% due to extensive first-pass metabolism, but this is sufficient for therapeutic effect with the ester prodrug enhancing absorption.
Onset of Action	Oral: Clinical effects (e.g., hot flush reduction) begin within 2-4 weeks of daily dosing; maximal effect by 8-12 weeks.
Duration of Action	Once-daily dosing maintains steady therapeutic effects; after discontinuation, symptoms return within several days to weeks depending on individual metabolism.

Classification & Brands

Dosing & administration

0.5 mg orally once daily.

Dosage form	TABLET
Renal impairment	GFR 30-89 mL/min: No adjustment. GFR 15-29 mL/min: 0.25 mg once daily. GFR <15 mL/min: Not recommended.
Liver impairment	Child-Pugh A: No adjustment. Child-Pugh B: 0.25 mg once daily. Child-Pugh C: Not recommended.
Pediatric use	Safety and efficacy not established in pediatric patients.
Geriatric use	No specific dose adjustment required; monitor renal function due to age-related decline.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for ELINEST (ELINEST).

Breastfeeding	Excreted in human milk; M/P ratio 0.6:1.0. Potential for serious adverse reactions in nursing infants; contraindicated during breastfeeding.
Teratogenic Risk	Pregnancy Category X. Contraindicated in pregnancy due to documented teratogenicity. First trimester exposure associated with cardiovascular and neural tube defects; second and third trimester exposure linked to fetal hypothalamic-pituitary-ovarian axis disruption.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives (COCs). Women over 35 who smoke should not use COCs.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Thrombophlebitis or thromboembolic disorders","Cerebrovascular or coronary artery disease","Known or suspected breast carcinoma","Estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Pregnancy","Benign or malignant liver tumor or active liver disease","Renal impairment (creatinine clearance <30 mL/min)","Adrenal insufficiency","Hypersensitivity to any component"]

Clinical Precautions

Precautions

["Risk of thromboembolic disorders including stroke, myocardial infarction, and venous thromboembolism","Should not be used in women with hypertension, diabetes with vascular disease, or hyperlipidemias","May increase risk of gallbladder disease, hepatic neoplasia, and worsening of hereditary angioedema","May cause fluid retention, hyperkalemia in patients with renal impairment or on potassium-sparing drugs","Discontinue if jaundice, visual disturbances, or migraine with focal symptoms occur","May reduce folate levels; consider folate supplementation"]

Clinical Tips & Counseling

Drug interactions

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ELINEST

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ELINEST (ELINEST).

How it works

Ethinyl estradiol is an estrogen; drospirenone is a progestin with anti-mineralocorticoid and anti-androgenic activity. The combination suppresses gonadotropins, inhibiting ovulation.

What the body does with it

Metabolism	Ethinyl estradiol is metabolized via CYP3A4 and undergoes conjugation; drospirenone is metabolized primarily via CYP3A4 to inactive metabolites.
Excretion	~68% renal (50% unchanged, ~18% as inactive metabolites), ~30% biliary/fecal, with enterohepatic recycling of drug and estrogen conjugates.
Half-life	Terminal elimination half-life of estradiol (E2) is ~13-16 h, but due to the prodrug nature and accumulation of estrogen metabolites, the effective half-life during continuous use is ~36 h, supporting once-daily dosing.
Protein binding	~98-99% bound, primarily to sex hormone-binding globulin (SHBG) and albumin, with ~45% bound to SHBG and remainder to albumin.
Volume of Distribution	Apparent Vd for estradiol is ~0.6-0.7 L/kg, reflecting distribution into total body water and some tissue binding (e.g., fat and reproductive tissues).
Bioavailability	Oral: ~5% due to extensive first-pass metabolism, but this is sufficient for therapeutic effect with the ester prodrug enhancing absorption.
Onset of Action	Oral: Clinical effects (e.g., hot flush reduction) begin within 2-4 weeks of daily dosing; maximal effect by 8-12 weeks.
Duration of Action	Once-daily dosing maintains steady therapeutic effects; after discontinuation, symptoms return within several days to weeks depending on individual metabolism.

Classification & Brands

Dosing & administration

0.5 mg orally once daily.

Dosage form	TABLET
Renal impairment	GFR 30-89 mL/min: No adjustment. GFR 15-29 mL/min: 0.25 mg once daily. GFR <15 mL/min: Not recommended.
Liver impairment	Child-Pugh A: No adjustment. Child-Pugh B: 0.25 mg once daily. Child-Pugh C: Not recommended.
Pediatric use	Safety and efficacy not established in pediatric patients.
Geriatric use	No specific dose adjustment required; monitor renal function due to age-related decline.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for ELINEST (ELINEST).

Breastfeeding	Excreted in human milk; M/P ratio 0.6:1.0. Potential for serious adverse reactions in nursing infants; contraindicated during breastfeeding.
Teratogenic Risk	Pregnancy Category X. Contraindicated in pregnancy due to documented teratogenicity. First trimester exposure associated with cardiovascular and neural tube defects; second and third trimester exposure linked to fetal hypothalamic-pituitary-ovarian axis disruption.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives (COCs). Women over 35 who smoke should not use COCs.