Pharmacology is the science of the interaction between chemical substances and living tissues. If the chemical is primarily
beneficial its study falls under the title therapeutics if primarily harmful its study is called toxicology. In either case pharmacodynamics defines how the material is absorbed by the body where it acts what its effect is and how it is metabolized and excreted. Pharmacologists determine the therapeutic index of drugs that is the relative benefit to toxicity at various doses. This helps define the dosage of a drug that will most benefit a sick person. They also study how various conditions affect the excretion of drugs. For example many drugs are more slowly metabolized in older people so these drugs need to be administered less frequently. Because many chemicals are excreted by the kidney people with kidney disease may have impaired drug excretion. Doctors who specialize in
pharmacology are called clinical pharmacologists. Pharmacists who practice in hospitals also specialize in pharmacology and they can advise doctors on the optimal use of medicinal drugs.
Medicine development and safety testing
f the structure of a medicine is altered slightly this will slightly alter the medicine''s properties. This means when a useful activity as been identified chemists will make many similar compounds called analogues to try and maximise the beneficial effects. This development phase can take up to 3 years
typically and is expensive.
These new analogues need to be developed. It needs to be determined how safe the medicine is for human consumption, its stability in the human body and the best form for dispensing like tablet or aerosol. After lots of testing which can take up to 6 years the new medicine is ready for marketing.
As a result of the long time required to develop analogues and test a new medicine and the fact that of every 5000 potential new medicines typically only one will ever reach the open market this is an expensive way of doing things costing millions of Dollars. To recoup this outlay pharmaceutical companies may do a number of things:
Carefully research the demand for their potential new product before spending an outlay of company funds.
Obtain a patent on the new medicine preventing other companies from producing that medicine for a certain allocation of time.