Tretinoin Capsules are a retinoid-based targeted medication used for the treatment of acute promyelocytic leukemia (APL). It exerts its therapeutic effects by inducing the differentiation of leukemia cells and inhibiting their proliferation. However, strict adherence to medication guidelines is required to avoid risks such as embryotoxicity and differentiation syndrome.

How to Use Tretinoin Capsules

Indications and Diagnostic Confirmation

Tretinoin Capsules are indicated for APL patients in whom t(15,17) chromosomal translocation or PML/RARα fusion gene has been confirmed by cytogenetic or molecular testing, especially those who are resistant to or have contraindications for anthracycline chemotherapy.

Before medication administration, the indication must be clearly confirmed through morphological diagnosis combined with genetic testing to avoid incorrect use in non-target populations.

Administration Regimen

Dosage: The recommended dosage is 22.5mg/m², taken orally twice daily, until complete remission (CR) is achieved.

Treatment Course: After CR is achieved, continue medication for 30 days, or the total treatment course should not exceed 90 days (whichever comes first).

Administration Method: The capsules must be taken with meals and swallowed whole. They should not be chewed, dissolved, or opened, as this may affect the efficacy. If the time since a missed dose is more than 10 hours before the next scheduled dose, the missed dose can be taken; no additional dose is needed after vomiting.

Key Monitoring and Discontinuation Indications

During treatment, regular evaluation of blood routine, liver function, blood lipids, and coagulation function is required.

If t(15,17) translocation or PML/RARα fusion gene is not detected, medication should be discontinued immediately.

Dosage Adjustment of Tretinoin Capsules

Adjustment Related to Adverse Reactions

Differentiation Syndrome: The incidence is approximately 26%, manifested as fever, dyspnea, weight gain, etc. When symptoms occur, intravenous injection of dexamethasone (10mg every 12 hours) is required immediately, and tretinoin should be suspended until symptoms are relieved.

Intracranial Hypertension: More common in children. Dosage reduction or medication discontinuation is necessary, and concurrent use of tetracyclines and other drugs that may increase intracranial pressure should be avoided.

Hepatotoxicity: If liver enzyme levels rise more than 5 times the upper limit of normal, it is recommended to suspend medication until liver function returns to normal.

Impact of Drug Interactions

CYP3A Inhibitors/Inducers: Potent inhibitors (such as ketoconazole) may increase the blood concentration of tretinoin, requiring close monitoring for toxicity.

Potent inducers (such as rifampicin) may reduce the efficacy of tretinoin, and concurrent use should be avoided.

Antifibrinolytic Drugs: Concurrent use increases the risk of thrombosis and is strictly prohibited.

Medication for Special Populations with Tretinoin Capsules

Pregnant and Lactating Women

Contraindication in Pregnancy: Tretinoin has confirmed teratogenicity. A negative pregnancy test must be confirmed before medication, and double contraceptive measures should be taken during treatment and within 1 month after discontinuation.

Lactation Period: Breastfeeding is prohibited during treatment and within 1 week after the last dose.

Children and Elderly Patients

Children: Tretinoin can be used in children over 1 year old, but the risk of intracranial hypertension must be vigilant. Lumbar puncture for decompression or dosage reduction may be necessary if needed. The safety in children under 1 year old has not been established.

Elderly Patients: Compared with young patients, no dosage adjustment is required, but enhanced monitoring of adverse reactions is necessary.