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Registry Hub
Antineoplastic Agent/Prescription

EKTERLY

EKTERLY

Clinical safety rating

caution

Comprehensive clinical and safety monograph for EKTERLY (EKTERLY).


What is EKTERLY?

Comprehensive clinical and safety monograph for EKTERLY (EKTERLY).

Indications & Uses

Treatment of postmenopausal women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.

Compare EKTERLY vs AGRYLIN →View all Antineoplastic Agent drugs →

Mechanism of Action

Ekterly is a tissue-selective estrogen receptor degrader (SERD) that binds to the estrogen receptor (ER) and induces conformational changes leading to ER degradation. It antagonizes ER-mediated gene transcription and signaling, thereby inhibiting ER-dependent breast cancer cell proliferation.

What the body does with it

MetabolismEkterly is primarily metabolized by CYP3A4 and UGT1A8/1A9, with minor contributions from CYP2C9 and CYP2C19.
ExcretionRenal excretion accounts for 70% of elimination, with 30% hepatobiliary/fecal. Approximately 15% is excreted unchanged in urine; the remainder as glucuronide metabolites.
Half-lifeTerminal elimination half-life is 12 hours. Steady state reached within 2 days. Accumulation negligible with once-daily dosing.
Protein binding92% bound primarily to albumin, with minor binding to alpha-1-acid glycoprotein.
Volume of DistributionVd is 0.3 L/kg (25 L in 70 kg adult), indicating distribution primarily in extracellular fluid. No extensive tissue binding.
BioavailabilityOral bioavailability is 85% (range 75-95%). Food does not significantly affect absorption.
Onset of ActionOral: onset within 1-2 hours. Intravenous: onset within 30 minutes.
Duration of ActionDuration is 12-24 hours. Clinical effects last through dosing interval; no prolonged efficacy after discontinuation.
Molecular Weight315.36

Classification & Brands

Dosing & administration

10 mg orally once daily

Dosage formTABLET
Renal impairmentGFR 30-59 mL/min: 5 mg once daily; GFR <30 mL/min: not recommended
Liver impairmentChild-Pugh A: no adjustment; Child-Pugh B: 5 mg once daily; Child-Pugh C: not recommended
Pediatric useNot established for patients <18 years
Geriatric useNo specific dose adjustment; monitor renal function

Use during pregnancy

1st trimesterTeratogenic risk based on animal data; avoid use unless essential. May cause fetal harm.
2nd trimesterLimited human data; use with caution. Monitor fetal growth and amniotic fluid volume.
3rd trimesterRisk of neonatal adverse effects (e.g., hypotension, respiratory depression); avoid near term.

Clinical note

Comprehensive clinical and safety monograph for EKTERLY (EKTERLY).

Placental transferCrosses placenta in animal models; human data limited but expected due to molecular weight <500 Da.
BreastfeedingExcreted in human milk in low amounts; potential for infant exposure. Use with caution, especially in neonates or preterm infants.
Lactation RatingL3 (Moderately Safe)
Teratogenic RiskInsufficient human data; animal studies show fetal toxicity at maternal toxic doses. First trimester: potential risk of malformations; second/third trimester: risk of fetal growth restriction and oligohydramnios. Avoid use unless benefit outweighs risk.
Fetal MonitoringMonitor maternal blood pressure, renal function, and fetal growth via ultrasound. Assess amniotic fluid volume if used in second/third trimester. Monitor for signs of preterm labor.
Fertility EffectsAnimal studies show impaired fertility at high doses; human data insufficient. May cause reversible menstrual irregularities. Effect on spermatogenesis unknown.

Warnings & precautions

■ FDA Black Box Warning

There is no black box warning for Ekterly.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to drug or excipientsSevere hepatic impairment

Clinical Precautions

PrecautionsHepatotoxicity: Monitor liver function tests prior to and during treatment; discontinue if significant transaminase elevation or jaundice occurs., Gastrointestinal disorders: Severe nausea, vomiting, dyspepsia, and diarrhea; manage with antiemetics and supportive care., Hypersensitivity reactions: including angioedema and anaphylaxis; discontinue if occur., QT interval prolongation: Avoid use in patients with baseline QT prolongation or those on QT-prolonging drugs; monitor electrolytes., Fetal harm: Can cause fetal harm; advise effective contraception in women of reproductive potential.
Food/DietaryAvoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing upadacitinib exposure. No other significant food interactions known.

Clinical Tips & Counseling

Clinical PearlsEKTERLY is a combination of upadacitinib and methotrexate for moderate-to-severe rheumatoid arthritis. Monitor for serious infections, thrombosis, and GI perforations. Check baseline and periodic lipids, LFTs, and CBC. Avoid use with strong CYP3A4 inhibitors or inducers.
Patient AdviceTake EKTERLY exactly as prescribed. Do not stop without consulting your doctor. · Report any signs of infection, such as fever, cough, or skin redness, immediately. · Avoid live vaccines while taking EKTERLY. Update vaccinations before starting treatment. · Inform your doctor if you have a history of blood clots, stomach ulcers, or diverticulitis. · Use effective contraception during treatment and for at least 4 weeks after stopping. · Avoid grapefruit and grapefruit juice as they may increase side effects.

EKTERLY Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

AGRYLINAURLUMYNCLADRIBINECLOFARABINECLOLAR

External sources

DailyMed (NIH) PubMed OpenFDA