Coenzyme Q10 be measured in blood plasma, these measurements reflect dietary intake rather than tissue status. Currently, most clinical centers measure CoQ levels in cultured skin fibroblasts, muscle biopsies, and blood mononuclear cells. Culture fibroblasts can be used also to evaluate the rate of endogenous CoQ biosynthesis, by measuring the uptake of C-labelled "p"-hydroxybenzoate. CoQ shares a biosynthetic pathway with cholesterol. The synthesis of an intermediary precursor of CoQ, mevalonate, is inhibited by some beta blockers, blood pressure-lowering medication, and statins, a class of cholesterol-lowering drugs. Statins can reduce serum levels of CoQ by up to 40%. CoQ is not approved by
Specialty drugs in the United States be classified as a specialty medication by Magellan Rx Management. Specialty pharmaceuticals are defined as "high-cost oral or injectable medications used to treat complex chronic conditions". According to a 2013 article in the "Journal of Managed Care & Specialty Pharmacy", on the increasingly important role of specialty drugs in the treatment of chronic conditions and their cost, drugs are most typically defined as specialty because they are expensive. Other criteria used to define a drug as specialty include "biologic drugs, the need to inject or infuse the drug, the requirement for special handling, or drug availability only via a limited