Simeprevir, sold under the brand name Olysio among others, is a medication used in combination with other medications for the treatment of hepatitis C. It is specifically used for hepatitis C genotype 1 and 4. Medications it is used with include sofosbuvir or ribavirin and peginterferon-alfa. Cure rates are in 80s to 90s percent. It may be used in those who also have HIV/AIDS. It is taken by mouth once daily for typically 12 weeks. Common side effects include feeling tired, headache, rash, itchiness, and sensitivity to sunlight. In those with previous hepatitis B infection, active disease may recur. It is not recommended in those with significant liver problems. During pregnancy when used with ribavirin it may cause harm to the baby while when used with sofosbuvir its safety is unclear. Simeprevir is a HCV protease inhibitor. Simeprevir was developed by Medivir AB and Janssen Pharmaceutica. It was approved for medical use in the United States in 2013. It was removed from the World Health Organization's List of Essential Medicines in 2019. It is not available as a generic medication as of 2015.
Medical use Simeprevir is indicated treating chronic hepatic C (CHC) infection as a part of a triple antiviral treatment regimen consisting of two other drugs: peginterferon-alfa (PEG-IFN) and ribavirin (RBV). It is primarily effective in treating Hepatitis C virus (HCV) genotype 1 infected subjects with compensated liver disease, including cirrhosis. There are currently no studies that show Simeprevir's effectiveness as a single therapy for HCV. Simeprevir is generally used for HCV genotype 1 infected subjects, but off-label medical use has been indicated for type 4 genotype as well.
Dosing Simeprevir is dosed along with peg-IFN and RBV as triple therapy. Appropriate dosing of Simeprevir is dependent upon the patient's liver function, kidney function, viral load, and HCV genotype. This medication is not recommended for people with moderate or severe liver impairment and people with end-stage kidney disease since Simprevir was not studied for use in these patient populations. Simeprevir might be discontinued depending on their viral load. For instance, if the patient's viral load is detectable (>25 units/mL) during the 4th week of their treatment regimen, it is considered an inadequate treatment and simeprevir must be discontinued.
Contraindications Any contraindications that apply to peg-IFN and RBV apply to simeprevir since they must be used in combination during treatment of CHC. For example, people with sickle cell anemia are contraindicated to RBV therapy and are therefore contraindicated to simeprevir and peg-IFN combination therapy. Pregnant women and men whose female partners are pregnant are contraindicated for simeprevir since peg-IFN and RBV are known to cause birth defects.
Pregnancy Simeprevir is avoided in pregnant women or women planning to be pregnant because it going to be taken with RBV and Peg-IFN, which have both shown to cause fetal problems in animal studies. RBV has been shown to cause birth defects and fetal deaths in animal studies. Peg-IFN has been shown to cause abortions in animal studies. People must have a negative pregnancy test prior to starting therapy, use at least two effective birth control methods during treatment, and undergo monthly pregnancy tests. If pregnant women are exposed to any medication regimen containing ribavirin, they are encouraged to report this through the ribavirin pregnancy registry.
Adverse effects Severe itching (22%), sensitivity to sunlight (5%), and rash (25%) are some of the common adverse effects of simeprevir. Other side effects may include nausea, muscle pain, difficulty breathing and increased bilirubin. It may reactivate hepatitis B in those who have been previously infected. The European Medicines Agency (EMA) has recommended screening all people for hepatitis B before starting simeprevir for hepatitis C in order to minimize the risk of hepatitis B reactivation.
Combination treatment In March 2015, Gilead Sciences e-mailed warnings to health care providers about nine people that began taking its hepatitis C drugs ledipasvir/sofosbuvir or sofosbuvir along with amiodarone, daclatasvir, or simeprevir developed abnormally slow heartbeats and one died of cardiac arrest. Three required a pacemaker to be inserted. Gilead said the combinations aren't recommended and product labels will be updated.
Mechanism of action Like some other aminocyclopropanes, simeprevir is a hepatitis C virus protease inhibitor. Simeprevir is a NS3/4A protease inhibitor, thus preventing viral maturation through inhibition of protein synthesis. Simeprevir is administered as one capsule once daily with pegylated interferon and ribavirin for the treatment of genotype 1 or genotype 4 chronic hepatitis C in adult people with compensated liver disease (including cirrhosis), with or without HIV-1 co-infection, who are treatment naive or who have failed previous interferon therapy. Genotype 1 is the most prevalent form of hepatitis C virus (HCV) worldwide.
Pharmacokinetics Simeprevir is orally bioavailable. Its absorption increases when taken with food, and is therefore advised to be taken with food. The liver's CYP3A4 enzymes mainly break down simeprevir, but CYP2C8 and CYP2C19 enzymes can also play a role. Its half-life in the plasma is 41 hours in people with HCV. Its peak effect happens 4 to 6 hours after taking the medication. It is primarily excreted into the feces (91%).
Pharmacogenomics According to simeprevir's prescriber information, its efficacy in combination with peginterferon alfa and ribavirin is "substantially reduced in people with HCV genotype 1a with an NS3 Q80K polymorphism at baseline compared to people infected with HCV genotype 1a without Q80K polymorphism." People with Q80K polymorphism are not advised to take simeprevir.
… excerpt ends here. Continue reading the full article.
