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.
Oral Tablet: The 30 mg formulation is an oral, film-coated tablet designed for once-daily administration.
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.
Dosage Adjustment: The 30 mg strength is a specific dosage adjustment for patients who are also taking strong inhibitors of the CYP3A4 enzyme. The standard dose for daclatasvir is 60 mg.
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: A notable characteristic of daclatasvir is its potential for significant drug interactions. It is metabolized by the enzyme CYP3A4, and its dosage needs to be carefully managed when co-administered with strong inhibitors or inducers of this enzyme.
Advantages
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.
Broad Genotype Coverage: It is effective against multiple HCV genotypes, including genotypes 1 and 3, which makes it a versatile treatment option for a diverse patient population.
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.
Interferon-Free Regimen: The development of daclatasvir has been a major step in the move towards all-oral, interferon-free regimens for hepatitis C, which are more tolerable for patients and have better adherence rates.
Uses
Chronic Hepatitis C Infection: Daclatasvir is indicated for the treatment of chronic HCV infection in adults.
HCV Genotypes 1 and 3: The combination therapy is particularly effective for patients with HCV genotypes 1 and 3, including those 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.
Combination with Sofosbuvir: The 30 mg dose is used as part of a treatment regimen with sofosbuvir for patients who are also taking a strong CYP3A4 inhibitor, such as ketoconazole or clarithromycin, to prevent increased daclatasvir exposure.
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. Do not store them in the bathroom.
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 a certain timeframe. However, if it is almost time for the next dose, the missed dose should be skipped to avoid a double dose.
