Tretinoin Capsules are a retinoid-based targeted drug used for the treatment of acute promyelocytic leukemia (APL). It exerts its therapeutic effects by inducing the differentiation of leukemic cells and inhibiting their proliferation; however, it also carries serious risks such as embryotoxicity and differentiation syndrome.

Precautions for Administration of Tretinoin Capsules

Contraindications and Baseline Assessment

Contraindicated Populations: Contraindicated in patients hypersensitive to tretinoin or other retinoids. It is absolutely contraindicated in pregnant women (may cause fetal death or malformations).

Confirmation Before Administration: Patients must be confirmed to have the t(15,17) translocation or PML/RARα fusion gene via cytogenetic or molecular testing; otherwise, use of the drug is not recommended.

Pregnancy Screening: Women of childbearing age must undergo a pregnancy test with a sensitivity of ≥50 mIU/mL within 1 week before drug administration. Administration is only allowed if the result is negative.

Administration Specifications

Dose and Treatment Course: The recommended dose is 22.5 mg/m², taken orally twice daily, until complete remission is achieved. After remission is reached, continue administration for no more than 30 days, with a total treatment course not exceeding 90 days.

Administration Method: The capsules must be swallowed whole with meals; do not chew, dissolve, or open the capsules. If vomiting occurs after administration, do not take a supplementary dose—proceed with the next scheduled dose as planned.

Management of Missed Doses: If the time to the next scheduled dose is >10 hours, the missed dose can be supplemented; otherwise, skip the missed dose.

Management in Special Populations

Patients of Childbearing Age: Females must use dual contraceptive methods (e.g., hormonal contraception + barrier method) until 1 month after the last dose.

Male Patients: Must use effective contraception during treatment and for 1 week after discontinuing the drug.

Pediatric Patients: Can be used in children aged ≥1 year, but the risk of increased intracranial pressure must be closely monitored. Safety in children aged <1 year has not been established.

Lactation: Breastfeeding is prohibited during treatment and for 1 week after discontinuing the drug.

Risks of Drug Interactions

CYP3A Inhibitors/Inducers: Strong CYP3A inhibitors (e.g., ketoconazole) may increase plasma drug concentrations and enhance toxicity; strong CYP3A inducers (e.g., rifampicin) may reduce efficacy. Concurrent use of these drugs should be avoided.

Vitamin A and Other Retinoids: Concurrent use may exacerbate retinoid-related toxicity (e.g., dry skin, liver injury).

Antifibrinolytic Drugs (e.g., tranexamic acid): Increases the risk of thrombosis; concurrent use is prohibited.

Monitoring During Administration of Tretinoin Capsules

Efficacy Monitoring

Hematological Indicators: Monitor white blood cell (WBC) count weekly. 40% of patients may experience a rapid increase in WBC count (risk is higher when WBC >5×10⁹/L); consider concurrent use of cytoreductive chemotherapy based on clinical conditions.

Differentiation Syndrome: Occurs in 26% of patients, presenting with fever, dyspnea, weight gain, hypotension, etc. Once symptoms appear, intravenous dexamethasone (10 mg every 12 hours) must be administered immediately; temporary suspension of tretinoin may be necessary if required.

Lipid and Liver Function Monitoring

60% of patients develop hypercholesterolemia/hypertriglyceridemia. Fasting lipid levels should be regularly tested at baseline and during treatment.

50%–60% of patients experience elevated liver enzymes (ALT/AST). Monitor ALT/AST; consider discontinuing the drug if levels exceed 5 times the upper limit of normal (ULN).

Special Monitoring of Organ Function

Intracranial Pressure: Pediatric patients require particular vigilance for symptoms such as headache, blurred vision, and vomiting. If suspected, a neurological evaluation is needed, and potentially causative concurrent drugs (e.g., tetracyclines) should be discontinued.

Thrombotic Events: Venous/arterial thrombosis (e.g., stroke, myocardial infarction) is prone to occur in the first month of treatment. Monitor for signs such as limb swelling and chest pain.

Renal Function and Electrolytes: Differentiation syndrome may lead to acute renal failure; monitor urine output and serum creatinine.