Elacestrant(Orserdu) is a novel estrogen receptor antagonist designed for patients with ER-positive, HER2-negative advanced or metastatic breast cancer harboring ESR1 mutations. It inhibits the growth and spread of tumor cells by precisely targeting ERɑ.
Guidelines for the use of Elacestrant
The efficacy and safety of Elacestrant are highly dependent on standardized medication. Patients should strictly follow the dosage requirements and pay attention to individualized adjustment in special populations to reduce the risk of adverse effects.
Correct medication method
The recommended dose of Elacestrant is 345 mg once daily with a meal to reduce gastrointestinal reactions. Tablets should be swallowed whole and avoid chewing or crushing. If you miss a dose for more than 6 hours or you vomit, you should skip the dose and continue taking the dose as planned. For patients with hepatic insufficiency, the dose should be adjusted according to the Child-Pugh grade: patients with moderate liver impairment should be reduced to 258 mg, and patients with severe liver impairment should not be disabled.
Medication recommendations for special populations
Pregnant and breastfeeding women should avoid the use of Elacestrant because it may cause fetal malformations or affect the baby through breast milk. Women and male partners who wish to have children should use effective contraception during treatment and for 1 week after discontinuation. Older patients do not need to adjust the dose, but people over 75 years of age should be monitored with caution.
Rational drug use should be combined with individual patient differences and clinical monitoring. Regular assessment of liver function and blood lipid levels, timely treatment of common adverse reactions such as musculoskeletal pain and nausea are the keys to ensuring the safety of treatment.
Drug interactions with Elacestrant
Drug interactions may significantly affect the efficacy and toxicity of Elacestrant, and potential risks need to be avoided through scientific management.
Effect of CYP3A4 inhibitors versus inducers
Strong or moderate CYP3A4 inhibitors (e.g., clarithromycin) increase plasma concentrations of Elacestrant and increase the incidence of adverse effects; Inducers, such as rifampicin, reduce drug exposure and weaken efficacy. Clinically, these drugs should be avoided in combination, and treatment regimens should be adjusted if necessary.
Interaction of P-gp and BCRP substrates
Elacestrant may inhibit the P-gp and BCRP transporters, leading to an increase in the blood concentration of substrate drugs such as digoxin, which can cause toxic reactions. When combined, the dose should be adjusted according to the therapeutic window of the substrate drug, and the relevant indicators should be closely monitored.
The management of drug-drug interactions needs to be based on multidisciplinary collaboration. Clinicians need to thoroughly assess the patient's medication history, develop an individualized plan, and enhance patient education to avoid self-use of over-the-counter drugs or supplements.
Pharmacokinetics of Elacestrant
The pharmacokinetic characteristics determine the administration mode and efficacy stability of Elacestrant, which is an important basis for clinical use.
Absorption and Bioavailability
The peak blood concentration is reached 1-4 hours after oral administration, and the bioavailability is about 10%. Food can significantly affect absorption: a high-fat diet increases Cmax and AUC by 42% and 22%, respectively, in the 345mg dosage form, so it is recommended to take it with meals to improve the efficiency of drug use.
The effect of diet on the efficacy of the drug
Taking medication after a meal not only reduces gastrointestinal reactions such as nausea and vomiting, but also promotes drug absorption by delaying gastric emptying. Patients should avoid taking the drug on an empty stomach and keep the diet relatively stable to maintain a stable blood concentration.
Pharmacokinetic studies provide scientific support for optimizing drug strategies. The combination of diet management and medication time control can maximize the efficacy and reduce the differences in drug efficacy between individuals, bringing long-term survival benefits to patients.
