Bimetinib should focus on the risks of cardiomyopathy, hepatotoxicity, and retinopathy, and regular monitoring of relevant indicators and timely intervention are necessary. The following are specific precautions and management measures.

Monitoring and Management of Cardiomyopathy

Combination therapy may lead to a decrease in left ventricular ejection fraction. Cardiac function needs to be evaluated before treatment, and regular follow-up echocardiography is required during the treatment period. If symptoms such as palpitations and difficulty breathing occur, the medication should be immediately interrupted and cardiac function should be evaluated. Reduce or permanently discontinue medication based on severity.

2 Hepatotoxicity Management

Monitor ALT/AST levels monthly and increase detection frequency when abnormalities occur. If ALT/AST exceeds 3 times the upper limit of normal values, medication should be suspended and other liver injury factors should be investigated. When accompanied by an increase in bilirubin, the medication needs to be permanently discontinued. Patients with moderate liver damage need to reduce their dosage to 30mg per dose.

(1) Classification and treatment of liver function abnormalities

Level 1 (<3 times ULN): Continue medication; Level 2 (3-5 times ULN): Pause until reduced after recovery; Level 3 (>5 times ULN): permanent discontinuation of medication. Patients with elevated bilirubin levels should discontinue use directly.

Prevention and control of retinal lesions

Check for changes in vision during each visit and pay attention to symptoms of blurred vision or blind spots. If serous retinopathy occurs, treatment should be interrupted. If it does not improve within 4 weeks, medication will be permanently discontinued. Retinal vein occlusion requires immediate termination of treatment and referral to ophthalmology.

(1) Ophthalmic examination frequency

A comprehensive ophthalmic assessment is required at baseline, and OCT should be rechecked every 2-3 months during treatment. Those with a history of diabetes retinopathy should be shortened to monthly examination.