Description

Hepcinat 400mg (Sofosbuvir) is a nucleotide analog inhibitor of hepatitis C virus NS5B polymerase—the key enzyme mediating HCV RNA replication. Sofosbuvir is a prodrug and after ingestion it is rapidly converted to GS-331007, the predominant circulating drug that accounts for greater than 90% of the systemically active drug. The compound GS-331007 is efficiently taken up by hepatocytes, whereby cellular kinases convert GS-331007 to its pharmacologically active uridine analog 5’-triphosphate form (GS-461203). This triphosphate compound mimics the natural cellular uridine nucleotide and is incorporated by the HCV RNA polymerase into the elongating RNA primer strand, resulting in chain termination. The active form GS-461203 targets the NS5B catalytic site and acts as a non-obligate chain terminator. The active compound (GS-461203) does not inhibit host DNA polymerases, RNA polymerases, or mitochondrial RNA polymerase. Hepcinat is available as a 400 mg tablet. The recommended dose of sofosbuvir is 400 mg taken orally once daily, with or without food. The 400 mg dose of sofosbuvir should be used, regardless of the patient's genotype and prior hepatitis C treatment experience. No dose adjustment is needed for mild-to-moderate renal impairment or with mild, moderate, or severe hepatic impairment. Hepcinat has been very well-tolerated in clinical trial. The most common adverse effects observed with sofosbuvir, when used in combination with ribavirin, have been fatigue and headache. Sofosbuvir is pregnancy category B. The major concern with drug interactions exists with medications that are strong inducers of intestinal P-gp, such as rifampin and St. John's wort, since these compounds may significantly lower sofosbuvir and GS-331007 levels. The coadministration of sofosbuvir with the following medications is not recommended because these medications may significantly lower sofosbuvir levels: Anticonvulsants: carbamazepine, oxycarbazepine, , and phenytoin Antimycobacterials: , rifampin, rifapentine Herbal Supplements: St. John's wort (Hypericum perforatum) HIV Protease Inhibitiors: tipranavir