The contraindications of Mekinist involve specific populations, dietary restrictions, and medication conditions, and must be strictly followed to avoid serious adverse reactions. The following provides a detailed explanation from three aspects: classification of taboo populations, food interactions, and special restrictions.

1. Taboo population

(1) Pregnant women: Based on animal studies showing teratogenic risks, effective contraceptive measures should be taken during medication and 4 weeks after discontinuation. Pregnant women with positive test results are prohibited from using them.

(2) Breastfeeding women: It is unclear whether the medication is secreted through breast milk. Breastfeeding should be stopped during treatment and within one week after the last dose.

(3) Severe liver dysfunction: Not recommended for Child Pugh C patients, with mild to moderate damage requiring reduced dosage and close monitoring of transaminase levels.

2. Forbidden foods

(1) Grapefruit/grapefruit: Contains strong CYP3A4 inhibitors, which may increase the blood concentration of trametinib and increase the risk of toxicity.

(2) St. John's wort: induces CYP3A4 metabolic enzymes, reduces drug efficacy, and should be avoided for simultaneous use.

3. Restrictive conditions

(1) Cardiovascular disease: Patients with baseline QTc>500ms or uncontrolled heart failure are contraindicated, and regular monitoring of electrocardiogram is required during treatment.

(2) Ophthalmic diseases: Use with caution in individuals with a history of retinal vein occlusion. Prior to medication, a fundus examination should be completed and re examined every 3 months.

(3) Drug combination: Do not use with potent CYP3A4 inducers (such as rifampicin), as it may lead to treatment failure.