Drugs are chemical compounds which prevent diseases and infections. Anciently plants/plant parts were used to ameliorate certain disease symptoms. Chinese/Indians/German herbal medicines have been used for years. The methodology to use plants for treatment is to isolate the pharmacologically active drug from the plant and hence treat. An example of this is Foxglove where the active molecule is digitalis and this stimulates heart muscles. Some others being Taxol used for anti-cancer treatment and Quinine for anti-malaria. Some natural elements like Elemental Sulphur and Platinum are also used for treating certain ailments. Sulphur was first used in the Second World War to treat secondary infections. Sprinkling sulphur over the wound prevents sepsis. Platinum on the other hand helps in tumor regression, but they cannot be used on a long term basis. The new drugs Platinex are used for treatment of cancer. Vaccines were discovered by Edward Jenner against Small pox which caused mortality between 50-60 percent. Later antitoxins and antivenis were discovered. Antivenis are drugs for snake bites and these are prepared from small doses from different snakes and animals. Then injected in horses, after which the horse's blood is centrifuged in order to obtain the plasma which neutralize toxins.
The first recombinant DNA (rDNA) drug was the Humulin. This was given to people who produced insufficient amounts of insulin. Two Canadian scientists were responsible for the discovery of this miracle. The pancreas from pigs was isolated, which were then injected into humans who were diabetic. This was plausible because the pigs and humans had similar physiology. Later Genentech licensed insulin to Eli Lilly. This had an advantage over the pig insulin as the human insulin gene was cloned and inserted into humans. Alpha interferon was the second recombinant drug, initially used for capasis skin cancer but was also the first drug used for HIV. Some other rDNA drugs were pulmozyme developed by Genentech, which is used to treat cystic fibrosis. Activase TPA a clot buster was one other rDNA. Monoclonal antibodies used as drugs are also an in thing in the market. The first one of this kind was Herceptin. Secondary metabolites are also used as effective drugs to treat some other diseases. Chemotherapeutics are chemically synthesized drugs which are also affectively used for treatment.
Some Drug concepts
While taking cancer chemotherapy there is an occurrence of killing even the normal cells and hence the side effects are seen. A traditional chemotherapy fails to distinguish normal cell and tumor cell. Epithelial cells lining our head and gut losses a turnover. Highly specific drugs can avoid these issues. For the development of these specific drugs understanding of ADME is essential. ADME stands for absorption, distribution, metabolism and excretion. This is a very important pharmacokinetic property.
Pharmacoeconomics which means the cost in making the drug in balance with the disease occurrence is an important aspect to be considered. Drug must be manufactured in large amounts and must be economically feasible. In order to make sure the drug is feasible and produced in large amounts, lots of investment is needed. This funding is provided in a number of ways to companies to manufacture the drug. CRO 's also called as Clinical Research Organizations help in the form of outsourced pharmaceutical research services. They perform different services for a fee for example GLP toxic studies. This supports initiation of IND, test drugs which are also done by contract labs and help in FDA approvals.
The story of VIOXX
NSAID's were the first drugs to be used for the treatment of Rheumatoid Arthritis. NSAID's are Non- steroidal anti inflammatory drugs. The most common side effect of NSAID is GI bleeding. 100mg of this drug did wonders for RA but did not resolve the GI bleeding problem. Then came along VIOXX in an effort to combat this problem and also cure RA to a certain extent, however there was an increased incidence in vascular disorders (heart attacks/ stroke.) Merck was accused of concealing the side effect and law suits were filed. Many people sued Merck saying they did not bring into notice of the people the safety protocols. Later however Merck voluntarily removed Vioxx from the market.
There are number of obstacles which come in the way of development of a drug or vaccine. In short the risks versus the benefits must be measured, always the benefits must outweigh the risks else the drug is not successful.
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A scientific writer