Direct-Acting Antiviral (DAA): Daclatasvir is a medication that belongs to the class of direct-acting antivirals, which target specific steps in the viral life cycle.
Standard Oral Dosage: The 60 mg formulation is the standard once-daily oral dosage for treating chronic hepatitis C virus (HCV) infection in adults.
Combination Therapy: It is a component of a combination therapy and must not be administered as a monotherapy. It is typically used with other antivirals, such as sofosbuvir, to treat chronic hepatitis C virus (HCV) infection.
Used for Multiple Genotypes: The medication is effective against multiple HCV genotypes, including genotypes 1 and 3, which are some of the most common types of the virus.
Nature
Drug Class: Daclatasvir is a Hepatitis C virus NS5A inhibitor.
Mechanism of Action: The drug works by binding to a protein called nonstructural protein 5A (NS5A). NS5A is a crucial phosphoprotein in the HCV life cycle, involved in both viral RNA replication and the assembly of new viral particles.
Inhibition of Replication and Assembly: By inhibiting NS5A, daclatasvir effectively blocks two key stages of the virus’s life cycle: the replication of viral RNA and the assembly and secretion of new virions. This dual mode of action contributes to its high potency.
Drug Interactions and Metabolism: A notable characteristic of daclatasvir is its metabolism by the enzyme CYP3A4. Its dosage needs to be carefully managed, as co-administration with strong inhibitors or inducers of this enzyme can significantly affect its plasma levels and efficacy.
Advantage
High Cure Rate: When used in combination with other DAAs like sofosbuvir, daclatasvir has demonstrated high rates of sustained virologic response (SVR), with cure rates often exceeding 90% across various HCV genotypes.
Well-Tolerated: The drug is generally well-tolerated with a favorable safety profile. The side effects are often mild, such as headache and fatigue, and it avoids the severe side effects associated with older interferon-based therapies.
Pan-Genotypic Activity: Daclatasvir exhibits a broad spectrum of activity against several HCV genotypes, making it a versatile option for patients with different strains of the virus.
Interferon-Free Regimen: The development of daclatasvir has enabled the use of all-oral, interferon-free regimens for hepatitis C, which are more tolerable for patients and have better adherence rates than previous treatments.
Uses
Chronic Hepatitis C Infection: Daclatasvir is indicated for the treatment of chronic HCV infection in adults.
In Combination with Sofosbuvir: The 60 mg dose is the standard regimen when used in combination with sofosbuvir for patients with HCV genotypes 1 or 3, with or without cirrhosis.
Challenging Patient Populations: It is used in difficult-to-treat patient populations, such as those with HIV co-infection, advanced cirrhosis, or recurrent HCV infection after a liver transplant.
Dosage Adjustment: The 60 mg dose is the standard, but it may be adjusted down to 30 mg with strong CYP3A4 inhibitors or up to 90 mg with moderate CYP3A4 inducers to maintain therapeutic efficacy and safety.
Storage
Temperature: Daclatasvir tablets should be stored at a controlled room temperature, typically not exceeding 30∘C (86∘F).
Protection: Keep the tablets in their original, tightly closed container, protected from light, moisture, and excessive heat.
Administration: The tablets should be swallowed whole and not chewed, crushed, or split. It can be taken with or without food.
Missed Dose: If a patient misses a dose, they should take it as soon as they remember, within 20 hours of the scheduled time. If more than 20 hours have passed, the missed dose should be skipped to avoid a double dose.
