The contraindications of voriconazole (Vfend) involve specific populations, food interactions, and medication restrictions, which need to be strictly avoided to reduce the risk of serious adverse reactions. Special attention should be paid to individuals with CYP2C19 metabolic abnormalities and the use of potent enzyme inducers in combination.

1. Taboo population

(1) Genetic metabolic abnormalities

Patients with CYP2C19 ultra fast metabolism may have insufficient blood drug concentration, while those with slow metabolism are prone to accumulation and poisoning. It is recommended to undergo genetic testing before medication.

(2) Special physiological state

Pregnant women are prohibited (animal teratogenic risk level D), and feeding should be suspended during lactation; Oral preparations are prohibited for children under 12 years old, and intravenous preparations require strict evaluation.

(3) Organ dysfunction

Severe liver cirrhosis (Child Pugh C grade) is contraindicated; If the creatinine clearance rate is less than 50ml/min, oral preparations are prohibited, and the dosing regimen needs to be adjusted for hemodialysis patients.

2. Forbidden foods

(1) Grapefruit products

Furancoumarin can inhibit CYP3A4 and increase the AUC of voriconazole by three times. It is necessary to completely avoid intake during treatment.

(2) High-fat diet

The bioavailability of oral preparations is reduced by 20%, and should be taken 1 hour before or 2 hours after meals, avoiding co administration with dairy products.

3. Restrictive conditions

(1) Contraindications for drug combination therapy

Prohibit the use of strong CYP450 inducers such as rifampicin and carbamazepine in combination; When used in combination with sirolimus, the dosage should be reduced to 1/10 and blood drug concentration should be monitored.

(2) Course control

Continuous treatment for more than 6 months requires assessment of liver toxicity risk, and if visual impairment persists for more than 48 hours, the medication must be permanently discontinued.

(3) Monitoring requirements

Baseline electrocardiogram (QTc>500ms is prohibited) is required before treatment. ALT/AST should be monitored weekly for patients with abnormal liver function, and dermatological consultation is needed for patients with photosensitive reactions.