Читать книгу Fundamentals of Pharmacology for Paramedics - Группа авторов - Страница 29

Enzymes are the large proteins that catalyse the thousands of biochemical reactions that maintain physiological function. An enzyme carries out the catalysis (speeding up) of a particular reaction by binding the reacting molecules and making it ‘easier’ for the reaction to occur (Figure 1.2). Drugs which have enzymes as their targets tend to be inhibitors of those enzymes, preventing the normal reacting substances from binding with the enzyme for catalysis.

Drugs such as non‐steroidal anti‐inflammatory drugs (NSAIDs), the prototype of which is aspirin, act by inhibiting the enzyme cyclo‐oxygenase, which is responsible for speeding up the reaction producing a range of important signalling molecules known as prostaglandins. It is the reduced level of prostaglandins as a result of blockade of cyclo‐oxygenase that produces the range of effects associated with NSAIDs. Another example of a widely used class of drugs which act by blocking an enzyme is the statin class, including atorvastatin and fluvastatin. These drugs lower cholesterol levels by inhibiting the enzyme HMG‐CoA reductase, responsible for the production of cholesterol in living cells.