Sofovir contains an anti-viral agent known as sofosbuvir Sofovir is a single fixed dose combination of two nonstructural protein inhibitors like NS5B. Sofosbuvir is used with other antiviral drugs to prevent hepatitis c viral infection. Sofovir is a prescription drug used under the supervision of medical practioners
Sofovir therapeutic indication
Sofovir is used for the treatment of chronic hepatitis C viral infection. In decompensated cirrhosis, Sofovir tablets are combined with ribavirin
The major limitation of use during Sofovir therapy;
In hepatitis C viral genotype III infected patients with cirrhosis getting Daclatasvir in combination with sofosbuvir for 12 weeks leads to cause reduction of sustained virological response rate frequently.
Sofovir mechanism of action
Sofovir – Sofosbuvir
Sofosbuvir is pharmacologically categorized as uridine monophosphate analogue prohibitor of HCV polymerase. The mechanism of action of sofosbuvir is basically involved in RNA replicates inhibitor.
Sofosbuvir is available as prodrug which gets converted into an active uridine triphosphate and inserted the active moiety into viral RNA by NS5B polymerase enzyme causes chain elimination.
Sofovir ADME properties
The peak plasma concentration time of sofosbuvir is 0.5 to 1 hour
Sofosbuvir plasma protein binding capacity 61 to 65%
The metabolism of both Sofovir is occurs hepatically Sofosbuvir: cathepsin A, carboxyl esterase 1 or HINT1
Sofosbuvir half life is 0.4 hour & GS-331007: 27 hours Sofosbuvir: 80% through urine, 14% through feces.
The usual dosage of Sofovir by combination with other medicines;
Patient obtained with genotype I, IV, V or VI chronic hepatitis C viral infection:
Sofovir is combined with ribavirin and peg interferon alfa should be taken as a single dose for 12 weeks
Sofovir and ribavirin should be taken in case of patients are undesirable to take peg interferon alfa for 24 weeks
Patients suffered with genotype II chronic hepatitis C:
Sofovir should be combined with ribavirin as a single dose for 12 weeks
Patients with genotype III hepatitis:
Sofovir combined with ribavirin and peg interferon alfa and it should be taken as a single dose for 12 weeks Otherwise Sofovir with ribavirin should be taken as single dose for 24 weeks
In liver transplantation:
Sofovir should be concurrently used with ribavirin as a single dose until liver transmission.
Sofovir tablet is recommended for the children at age 12 or weight of at least 35kg;
In without cirrhosis or with child Pugh A or compensated:
The recommended dosage is one tablet of Sofovir should be combined with weight-based ribavirin as a single dose for 12 weeks
In decompensated cirrhosis:
The prescribed dosage of Sofovir is one tablet should be used with ribavirin for 24 weeks
Ribavirin is prescribed to consume in two divided doses only with food Initial dose 600mg slowly increased up to 100mg per day in weight less than 75kg 1200mg should be taken per day with the weight at least 75kg
In pediatric ribavirin dosage;
<47kg: 15mg/kg/day 47 to 49kg: 600mg/day 50 to 65kg: 800mg/day 66 to 80kg: 1000mg/day >80kg: 1200mg/day No dosage adjustment is followed in the therapy using Sofovir in case of renal and hepatic impairment.
GenerallySofovir is administered with or without food. Sofovir is taken as a single dose The patients should give tablet by crushing or chewing the tablet, swallow the tablet as whole with some water
No specific antidote is required for over dosage of sofosbuvir. In case of over dosage, patient should be provided with general supportive management. Manifestation due to over dosage condition should be monitored. Over dosage should be treated by undergoing hemodialysis.
Sofovir adverse effects
Symptomatic bradycardia while combining with amiodarone Headache, Fatigue, Anemia, Increased AST, ALT, Increased bilirubin, Increased lipase, Nausea, Diarrhea, Insomnia, Dizziness, Somnolence
Risk of HBV reactivation
This fatal case is occurs in the patient who is receiving anti-HCV therapy. Prevent the problem by measuring HBsAg & anti-HBc levels of patients before starting the treatment. Hepatic function test should be monitored frequently and maintain the hepatic enzymes. Initiate the HBV infection management for the patients.
Loss of virological response
Due to advancement of resistance of Daclatasvir it should be combined with other abnti-viarl agents like sofosbuvir for better activity.
Avoid concurrent use of Sofovir with amiodarone Monitor the ECG Provide alternative medication for reducing the cardiac issues Counsel the patients before initiate the therapy about the risk associated with these combination.
Risk related to ribavirin
Ribavirin is contraindicated to pregnancy because it causes fetal harm even to death.
Combination of P-gp inducers
The combination of Sofovir with P-gp inducers causes loss of activity by decreasing the sofosbuvir concentration.