As an antiviral drug for hepatitis C, the use of Daclatasvir requires special attention to drug interaction risks and liver function monitoring requirements. The following are key considerations for the contraindications and liver safety of this drug when used in combination.

Drug interactions

(1) Strong CYP3A4 inducers such as rifampicin and carbamazepine can significantly reduce the blood concentration of daratavir and should not be used in combination.

(2) Intermediate acting CYP3A4 inducers such as bosentan and efavirenz require adjusting the dose of daratavir to 90mg/day.

(3) CYP3A4 inhibitors such as ketoconazole may increase the concentration of daratavir, and adverse reactions should be closely monitored when used in combination.

(4) Gastric acid regulator: H2 receptor antagonists should be taken every 12 hours, and PPI drugs should be avoided from being used simultaneously.

2 Liver function monitoring

(1) Baseline examination: ALT, AST, bilirubin and other indicators must be tested before starting treatment.

(2) Routine monitoring: During the treatment period, liver function will be rechecked every 4 weeks, and the monitoring frequency will be increased when abnormalities occur.

(3) Cirrhotic patients: Child Pugh B/C grade need to adjust the dosage to 30mg/day and monitor liver function weekly.

(4) Medication discontinuation indication: When ALT elevation exceeds 10 times ULN or bilirubin elevation exceeds 2 times ULN, immediate discontinuation of medication is recommended.

3 Precautions for Special Groups

(1) Complicated infection of hepatitis B: preventive use of anti hepatitis B drugs is required to avoid hepatitis recurrence.

(2) Liver transplant patients: It is necessary to closely monitor the blood concentration of immunosuppressants and liver function.

(3) Elderly patients: It is recommended to increase the frequency of liver function monitoring for those over 65 years old.

4 Other important warnings

(1) Avoid using Saint John's wort extract in combination as it may result in treatment failure.

(2) Combined use with amiodarone may cause severe bradycardia and require electrocardiographic monitoring.

(3) When used in combination with digoxin, the blood concentration of digoxin should be monitored.