What Is the Difference between Telaprevir and Boceprevir?

Telaprevir and boceprevir are both drugs that can help people who have Hepatitis C infections. Both of the medications block a particular enzyme that the Hepatitis C virus needs to replicate, and are commonly used in conjunction with other medicines. The way in which the drugs need to be taken differ, however, and the side effects are not all the same with the two drugs.

Although telaprevir and boceprevir have similar actions inside the body, they are different molecules, and do not have the same structure. Telaprevir has a chemical formula of C₃₆H₅₃N₇O₆, which means that the molecule has 36 carbon atoms, 53 hydrogens, 7 nitrogens and 6 oxygens. Boceprevir, on the other hand, has a chemical formula of C₂₇H₄₅N₅O₅, and is a lighter molecule than telaprevir, with a molecular weight of 519.7 grams per mole (g/mol) as opposed to telaprevir's 679.85 g/mol.

Both telaprevir and boceprevir act on an enzyme that the Hepatitic C virus (HCV) produces. This enzyme is called non-structural protein 3 (NS3) serine protease, and it is essential for the virus to make copies of itself. If one of the drugs blocks this enzyme from working, then the amounts of the individual virus particles in a patient's body drop over time.

Ribavirin and peginterferon alfa are two medicines that are commonly part of a treatment regimen that includes one of the telaprevir and boceprevir drugs. When a person with HCV is undergoing telaprevir treatment, he or she takes all three drugs together for three months, and then stops taking telaprevir. Boceprevir treatment, on the other hand, requires the patient to take ribavirin and peginterferon alfa over the space of a month before starting on boceprevir. A typical regime of boceprevir then involves about three to 11 months of concurrent treatment with the three drugs together.

When a person takes telaprevir, he or she needs to ingest some fat in order to help the body absorb the drug. A typical recommendation is 20 g of fat in the half hour before taking the telaprevir medication. Boceprevir patients need not take any special measures with food apart from eating at the the same time as taking the drug.

Each of the drugs can produce side effects such as stomach upset or diarrhea. Boceprevir is more likely to cause hair loss or provoke irritation in patients than telaprevir, and it is also capable of interfering with sleep. Telaprevir, on the other hand, tends to produce skin problems more often than boceprevir treatment programs do.