Correct usage, dosage and medication precautions of Entrectinib

Entrectinib (Entrectinib) is an innovative oral small molecule targeted drug, which belongs to the tyrosine kinase inhibitor (TKI) class of drugs and is mainly used to treat patients with NT Patients with locally advanced or metastatic solid tumors and non-small cell lung cancer (NSCLC) with RKfusion genes or ROS1 rearrangements. As a "broad-spectrum" targeted tumor treatment drug, entrectinib has been approved for marketing by the US FDA and the National Food and Drug Administration of China (NMPA). In order to ensure the best efficacy of the drug and minimize adverse reactions, it is important to correctly understand the usage and dosage of entrectinib and the precautions for taking the drug. The following details the dosage recommendations, medication methods, adverse reaction management, and combined medication.

1. Recommended usage and dosage of entrectinib

Enrectinib is an oral preparation, and the common dosage forms in China and the international market are 100mg and 200mg capsules. The recommended dosage is as follows:

Adults and adolescent patients 12 years old and above weighing ≥20kg: The recommended dose is 600mg taken orally once a day without fasting.

Pediatric patients weighing <20kg: The dose needs to be adjusted individually. It is recommended to use the mg/kg weight calculation method. For details, please refer to the pediatric dosage form or consult a professional physician.

Daily medications should be taken at the same time period to maintain stable blood concentrations. The drug should be swallowed whole and the capsule should not be chewed, opened or dissolved to avoid affecting the release of the drug effect.

2. Precautions when taking medicine

1.Eating and medication time

Entrectinib can be taken on an empty stomach or with food and has minimal effects on food absorption. However, it is recommended to take it at a fixed time every day to reduce fluctuations in blood concentration and improve the stability of the efficacy.

2.Missed dose and make-up dose

If you forget to take the medicine, if it is more than 12 hours before the next dose, you can take it immediately; if it is less than 12 hours, you should skip the missed dose and continue taking the medicine according to the normal plan. Do not take a double dose.

3. Basis for dose adjustment

If serious adverse reactions occur, such as Grade 3 or Grade 4 liver function abnormalities, central nervous system toxicity, QT interval prolongation, etc. , the use needs to be suspended or reduced according to the doctor's advice. The common dosage adjustment is from 600mg to 400mg or 200mg.

4.Drug withdrawal management

Entrectinib is a continuous treatment drug and self-discontinuation should be avoided. If the medication needs to be discontinued, a doctor should assess the condition and formulate a discontinuation plan. Abrupt discontinuation of treatment may lead to rapid tumor progression.

3. Key points of adverse reaction management

Common adverse reactions of entrectinib include:

1. Central nervous system side effects: such as dizziness, memory loss, ataxia, etc., often appear in the early stages of medication. It is recommended that patients avoid driving and operating machinery while taking medication.

2.Gastrointestinal reactions: such as nausea, vomiting, and diarrhea. Anti-nausea drugs can be used in combination, and attention should be paid to hydration and dietary regulation.

3.Electrocardiogram abnormalities: Some patients have prolongation of the QT interval. It is recommended to conduct regular electrocardiogram and electrolyte tests before medication and during treatment.

4.Liver function impairment: Liver enzyme (ALT/AST) and bilirubin levels need to be monitored. If the increase is significant, the medication should be suspended and the need for dose reduction evaluated.

In addition, children and elderly patients have slightly different drug tolerances, and liver and kidney function should be assessed before use to adjust the dosage strategy.

4. Drug interactions and contraindications

1.Interactions with CYP3A enzyme-related drugs

Enrectinib is mainly metabolized by CYP3A enzyme. Therefore, coadministration with CYP3A strong inhibitors (such as ketoconazole, clarithromycin) or inducers (such as rifampicin, carbamazepine) will change its plasma concentration. Simultaneous use or dose adjustment should be avoided.

2. Combined with acidic drugs (stomach medicine)

The absorption of entrectinib may be affected by the gastric acid environment. If it needs to be combined with a proton pump inhibitor (such as omeprazole), it is recommended to take it at an interval or consult a doctor to change the appropriate drug.

3. Contraindicated during pregnancy and lactation

Entrectinib may have toxic effects on the fetus or infant and is contraindicated in pregnant and lactating women. Women of childbearing age should take effective contraceptive measures while taking the medicine, and continue to use contraception for at least 5 weeks after stopping taking the medicine.

4.Patients with renal and hepatic insufficiency

For patients with severe hepatic and renal insufficiency, the pharmacokinetics of entrectinib are not yet clear, and it is recommended to use it with caution or make individual dose adjustments according to the situation.

5. Efficacy monitoring and follow-up evaluation

While patients are receiving entrectinib treatment, the following should be monitored regularly:

Imaging examination: such as chest CT or PET-CT, once every 8-12 weeks to evaluate whether the tumor has shrunk or stabilized.

Molecular testing: If the disease progresses, the NTRK/ROS1 mutation status can be tested again to determine whether there are drug-resistant mutations (such as G595R, etc.), and the treatment plan can be changed if necessary.

Systemic assessment: including electrocardiogram, liver and kidney function, electrolytes, cognitive status assessment, etc. to ensure the safety and tolerability of the drug.

Enrectinib, as a broad-spectrum, highly selective targeted drug, has shown good efficacy in ROS1-positive non-small cell lung cancer and NTRK fusion-positive solid tumors. Its correct usage and dosage and scientific medication management are of great significance for improving efficacy and reducing side effects. Patients should strictly abide by the doctor's instructions during treatment, take medications on time, monitor regularly, and pay attention to drug interactions and safety management. At the same time, family members and caregivers should also participate in supervision and support to help patients adhere to treatment and improve quality of life and survival. As more real-world data accumulate, the therapeutic prospects of entrectinib are still worth looking forward to.

Reference materials:https://www.drugs.com