Trade name: Velasof
Composition: Sofosbuvir & Velpatasvir
Strength of the components: 400mg & 100mg respectively
Manufacturer name: Hetero healthcare
Package: 28 tablets in a container
Classification: Anti-hepaciviral drug.
Drug Prescribing Information of Velasof tablets:
Velasof is used in following conditions like;
Patients suffered from compensated cirrhosis or without cirrhosis.
Patients with decompensated with long-lasting condition used in combination with ribavirin.
Velasof tablets are used in the conditions like hepatitis C viral infection in adolescents; HCV infection is caused by various genotypes like I, II, III, IV, V or VI.
Mechanism of Action of Velasof:
- A Velasof tablet containing directly acting anti-viral agents such as sofosbuvir & Velpatasvir which expels their actions by undergoing some mechanism includes;
- Sofosbuvir is an inhibitor of HCV NS5B RNA dependent RNA polymerase, an enzyme essential for viral production. Hence this inhibition causes depletion in viral proliferation.
- Velpatasvir is an inhibitor of HCV NS5A is a pan genotype, NS5A is a protein required for HCV viral replication thus the inhibition leads to reduce the production of HCV virus in the human body.
If gastric pH level increases lead to cause depletes insolubility of Velpatasvir.
The peak concentration time of both sofosbuvir and Velpatasvir occurs within 0.5 to 1 hour and 3 hours respectively.
The peak plasma concentration of sofosbuvir and Velpatasvir exist in 567ng/ml & 259ng/ml respectively.
The human plasma protein bound to sofosbuvir and Velpatasvir with the range of 61 to 65% and >99.5% respectively.
Sofosbuvir is metabolized hepatically, with the help of cathepsin A, CES1 & HINT1.
Sofosbuvir is a substrate of P-gp transporter and breast cancer resistance protein.
Velpatasvir is partially metabolized and it is excreted as an unchanged form.
The mean terminal half-life period of both sofosbuvir and Velpatasvir and the circulating metabolite called GS-331007 are reaching at 0.5 hours, 15 hours, & 27 hours respectively
The main routes of excretion of all the components like;
Sofosbuvir by metabolism; Velpatasvir through bile in unchanged form & GS-331007 through glomerular filtration and active tubular secretion.
Sofosbuvir: 80%; Velpatasvir: 14%
Sofosbuvir: 0.4%; Velpatasvir: 94%
When to take the Tablet Velasof:
Velasof tablets should be taken with or without food.
To administer the Velasof tablets frequently at the same time every day, as a single dose.
If concomitant with ribavirin, Velasof must be taken with food.
Gastric pH increasing drugs causes depletion in effect of serum concentration of Velpatasvir, to avoid these complications consume the antacids, H2 antagonist and proton pump inhibitors before the dose of Velasof.
Dosage Regimens of Velasof tablets:
Before initiating the therapy, patients should be examined by counting the hepatitis B surface antigen and hepatitis B core antibody (HBsAg & Anti-HBc) to prevent the problem like reactivation of HBV infection.
The prescribed dosage of Velasof tablets includes as;
Velasof containing fixed-dose combination drugs like 400mg of sofosbuvir and 100mg of Velpatasvir.
Recommended Velasof tablets in patients with chronic HCV infection related to genotypes like I, II, III, IV, V or VI.
Patients with child Pugh A: one tablet of Velasof should be administered as a single dose.
Patients with chronic cirrhosis or decompensated (child B or C): Velasof tablets should be combined with ribavirin.
The ribavirin dosage should be administered on the basis of the weight of the patients.
Less than 75kg: 1000mg per day; at least75kg: 1200mg per day.
No dosage adjustment is required for renal impaired patients.
Drug Called side effects:
Some effects may occur during the therapy of Velasof tablets;
Elevate lipase level
Elevation of creatinine kinase
Life-threatening condition like severe symptomatic bradycardia occurs while co-administration with amiodarone.
Drug Interaction of Velasof:
Velasof tablet combining with HMG CoA reductase agents leads to increase the concentration of these agents.
Velasof tablet concomitant with acid-reducing agents causes the decrease in the effect of concentration of Velpatasvir.
Velasof tablets are P-gp & BCRP drug transporters substrate while combining Velasof with P-gp inducers causes depletion in plasma concentration of Velasof tablet leads to reduce the curative effect.
Velasof tablet concurrently used with anti-mycobacterials causes depletion of Velasof tablet.
Velasof with amiodarone causes serious bradycardia.
Velasof tablet combined with digoxin causes increasing the serum concentration of digoxin.
Velasof tablet with anticonvulsants causes depletion of the effect of concentration of Velasof tablet.
Velasof tablet combined with HIV anti-retroviral agents leads to cause decrease the serum concentration of Velpatasvir.
Food -Drug Interactions:
No food-drug interaction occurs, an herbal product like st. Johns wort combining with Velasof causes decreasing the therapeutic effect of Velasof.
The anaphylactic reaction occurs while patients are contraindicated to the components present in Velasof tablet.
Velasof tablets while using alone it is safe if it is combined with ribavirin which is contraindicated in pregnant women.
Ribavirin with Velasof tablets in chronic condition causes ill to pregnant women cause fetal harm.
Serious bradycardia occurs while combining with amiodarone.
While taking Velasof tablet some adverse effects occur, to avoid these conditions some precautions should be taken.
Care should be taken in renal and hepatic impaired patients:
After completion of therapy, reactivation of HBV infection occurs in the patients who are co-infected with HCV/HBV infections, to avoid these conditions investigate the patient by measuring HBsAg and anti-HBc.
Reduction in the therapeutic effect of Velasof, while the concomitant use of Velasof with P-gp inducers.
Pregnancy and Lactation:
Velasof used alone then its pregnancy category comes under B1; safe to use.
If Velasof combined with ribavirin, pregnancy category is X; causes fetal death.
Breastfeeding should not be recommended during therapy.
Storage and Handling:
Velasof tablets container should be stored at room temperature below 30oC.
Keep the container away from moisture, heat, and light.
Velasof is not a normal drug, it is prescription medicine used only by the patients who are all having a valid prescription.
If the patient fails to take the dose of Velasof tablet, must get advice from the physician and take the medicine within the time because it is single dose therapy.
Otherwise, the missed dose should be skipped and follow the regular dosing schedule.
No distinct antidote is applicable for overdosing of Velasof tablets; once the overdose occurs to confirm the presence of toxicity.
Check the crucial manifestations and give adjuvant measures.
The Hemodialysis is another method used in an overdose of Velasof tablets, can efficiently dispose of the dominant circulating metabolite of sofosbuvir, GS-331007 with eradicating ration of 53%.
Hence Velpatasvir is highly bound to the human plasma protein; it is not cleared by hemodialysis and gives incredible results.