Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
EKTERLY vs AGRYLIN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.
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.
Essential thrombocythemia (ET) to reduce elevated platelet counts and the risk of thrombotic complications
10 mg orally once daily
Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.
Terminal elimination half-life is 12 hours. Steady state reached within 2 days. Accumulation negligible with once-daily dosing.
Terminal elimination half-life: 1.3–1.5 days (31–36 hours) in patients with ET; allows twice-daily dosing.
Ekterly is primarily metabolized by CYP3A4 and UGT1A8/1A9, with minor contributions from CYP2C9 and CYP2C19.
Primarily metabolized by CYP1A2 to the active metabolite 3-hydroxyanagrelide, and to a lesser extent by CYP2C19 and CYP2D6.
Renal excretion accounts for 70% of elimination, with 30% hepatobiliary/fecal. Approximately 15% is excreted unchanged in urine; the remainder as glucuronide metabolites.
Renal: 80% (primarily unchanged drug), Biliary/Fecal: 5%
92% bound primarily to albumin, with minor binding to alpha-1-acid glycoprotein.
82–88% bound to plasma proteins (primarily albumin).
Vd is 0.3 L/kg (25 L in 70 kg adult), indicating distribution primarily in extracellular fluid. No extensive tissue binding.
30–36 L (approximately 0.45–0.5 L/kg for a 70 kg adult); indicates extensive tissue distribution.
Oral bioavailability is 85% (range 75-95%). Food does not significantly affect absorption.
Oral: 65–80% (median 73%)
GFR 30-59 m L/min: 5 mg once daily; GFR <30 m L/min: not recommended
No specific GFR-based recommendations; use with caution in renal impairment (Cr Cl <50 m L/min) and monitor closely.
Child-Pugh A: no adjustment; Child-Pugh B: 5 mg once daily; Child-Pugh C: not recommended
Child-Pugh A: No adjustment. Child-Pugh B or C: Reduce initial dose by 50% and titrate cautiously.
Not established for patients <18 years
Children ≥7 years: 0.5 mg orally once or twice daily; adjust based on platelet response. Maximum: 10 mg/day. Not established for <7 years.
No specific dose adjustment; monitor renal function
No specific adjustment; start at lower end of dosing range (0.5 mg twice daily) and monitor renal function and platelet counts closely.
There is no black box warning for Ekterly.
None
Hepatotoxicity: 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.
Cardiovascular risks: increased risk of ventricular tachycardia, QTc prolongation, and heart failure; use caution in patients with known cardiac disease.,Hematologic effects: monitor complete blood counts regularly due to risk of anemia, leukopenia, or thrombocytopenia.,Hepatic impairment: reduce dose in patients with moderate to severe hepatic impairment.,Renal impairment: use with caution in severe renal impairment.
Hypersensitivity to Ekterly or any excipients,Pregnancy,Lactation,Severe hepatic impairment (Child-Pugh C)
Severe hepatic impairment,Known hypersensitivity to anagrelide or any component of the formulation
Avoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing upadacitinib exposure. No other significant food interactions known.
Grapefruit and grapefruit juice should be avoided as they may increase anagrelide plasma concentrations. No other specific dietary restrictions; however, maintain adequate hydration to reduce risk of crystalluria.
Insufficient 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.
Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies) at doses less than the human therapeutic dose. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to fetus. First trimester: Avoid due to organogenesis risk. Second and third trimesters: Unknown risks; consider alternative therapy.
No human data; M/P ratio unknown. Drug likely excreted into breast milk due to low molecular weight. Use with caution, monitor infant for adverse effects.
It is not known whether anagrelide is excreted in human milk. No M/P ratio is available. Due to potential for serious adverse reactions in breastfed infants (e.g., thrombocytopenia, cardiovascular effects), advise women not to breastfeed during treatment and for at least 7 days after last dose.
No established dose adjustments in pregnancy. Increased plasma volume and renal clearance may reduce drug exposure; monitor clinical response and adjust empirically if needed.
No specific pharmacokinetic studies in pregnancy. Pregnancy-induced plasma volume expansion may lower drug concentrations, potentially requiring dose adjustment to maintain therapeutic effect. However, due to teratogenicity risks, avoid use in pregnancy. If necessary, start at lowest effective dose (0.5 mg/day) and titrate based on platelet count monitoring, not to exceed 10 mg/day.
EKTERLY 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.
Agrylin (anagrelide) is a phosphodiesterase III inhibitor used to reduce platelet counts in essential thrombocythemia. Monitor platelet count weekly during titration; target <600,000/µL. Avoid in patients with severe hepatic impairment (Child-Pugh C). Use with caution in cardiac disease due to risk of QT prolongation and arrhythmias. Anagrelide may increase bleeding risk, especially when combined with anticoagulants or NSAIDs. Discontinue 4-5 days before elective surgery.
Take 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.
Take exactly as prescribed; do not skip doses or double up.,Report any signs of bleeding (easy bruising, nosebleeds, black/tarry stools) or palpitations immediately.,Avoid NSAIDs like ibuprofen and aspirin unless directed by your doctor.,Do not consume grapefruit or grapefruit juice while taking this medication.,Inform all healthcare providers (including dentists) that you are on anagrelide.,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 EKTERLY vs AGRYLIN, answered by our medical review team.
EKTERLY is a Antineoplastic Agent that works by 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.. AGRYLIN is a Antineoplastic Agent that works by Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between EKTERLY and AGRYLIN depend on the specific clinical indication. These are both Antineoplastic Agent agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of EKTERLY is: 10 mg orally once daily. The standard adult dose of AGRYLIN is: Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.. 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 EKTERLY and AGRYLIN 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. EKTERLY is classified as Category C. Insufficient human data; animal studies show fetal toxicity at maternal toxic doses. First trimester: potential risk of malformations; second/third trimester: risk of fetal growth . AGRYLIN is classified as Category C. Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.