Codeine are not available without a prescription. Preparations containing pure codeine (e.g., codeine phosphate tablets or codeine phosphate linctus) are available on prescription and are considered S8 (Schedule 8, or "Controlled Drug Possession without authority illegal"). Schedule 8 preparations are subject to the strictest regulation of all medications available to consumers. In Canada tablets containing 8 mg of codeine combined with 15 mg of caffeine and 300 mg of acetaminophen are sold as T1s (Tylenol Number 1) without a prescription. A similar tablet called "A.C. & C." (which stands for Acetylsalicylic acid with Caffeine and Codeine) containing 325–375 mg of acetylsalicylic
Mevalonic acid precursor in the biosynthetic pathway known as the mevalonate pathway that produces terpenes and steroids. Mevalonic acid is the primary precursor of isopentenyl pyrophosphate (IPP), that is in turn the basis for all terpenoids. Mevalonic acid is chiral and the (3"R")-enantiomer is the only one that is biologically active. Mevalonic acid Mevalonic acid (MVA) is a key organic compound in biochemistry; the name is a contraction of dihydroxymethylvalerolactone. The carboxylate anion of mevalonic acid, which is the predominant form in biological environments, is known as "mevalonate" and is of major pharmaceutical importance. Drugs like statins (which lower levels of cholesterol)