Challenging medicine

1. Challenging medicine

2. Medicines and human health • Roadmap challenges • In Chemistry for Tomorrow’s World, the RSC says: • “Global change is creating enormous challenges relating to energy, food and climate change. It is both necessary and urgent that action be taken.” • In its Roadmap, the RSC identified priority areas in which the chemical sciences can support change. These are: • Energy • Food • Future cities • Human health • Lifestyle and recreation • Raw materials and feedstocks • Water and air • Of these, human health makes connections to medicinal chemistry and pharmaceuticals. [Details of all priority areas may be found at: http://www.rsc.org/ScienceAndTechnology/roadmap/priorityareas/index.asp] • Human health • “Improving and maintaining accessible health, including disease prevention. • Thanks to improvement in health care, people are healthier and live longer today than ever before. However, the progress in health over recent decades has been deeply unequal. Considerable and growing health inequalities exist in many parts of the world. • The nature of health problems is also changing. Longer lives and the effect of ageing have increased the burden of chronic disorders. While urbanisation and globalisation have accelerated worldwide transmission of communicable diseases.” • The challenges • Ageing • Diagnostics • Hygiene and infection • Materials and prosthetics • Drugs and therapies • Personalised medicine

3. What causes ill health Body chemistry In a healthy body numerous chemical reactions are happening − inside cells, on the surface of cells and in body fluids. Illness and disease may occur when some of these chemical reactions are disrupted, for example, by pathogens. Pathogens are organisms that cause disease. They include micro-organisms such as bacteria and viruses and other parasites such as worms. There are trillions of bacteria in a human body. Most are harmless, some are helpful (for example, to digest vegetables and make vitamins), but some cause stomach upsets, tonsillitis, ear infections and meningitis. Viruses can infect healthy cells and cause, for example, colds, flu, mumps, German measles and chicken pox. The human immune system A thousand million white blood cells of various types are made each day in a human body. They form part of the body’s immune system. This uses a complex network of proteins, cells, tissues and organs to protect the body against attack from pathogens. When infected with germs, your body's defence is often inflammation. Blood flow to the affected area increases, making it red, swollen and tender. Blood vessels become 'leaky', allowing defender cells to reach the infected area. Some produce chemicals that kill bacteria or virus-infected cells. Others clear up the debris or feed on and digest bacteria. Chickenpox is caused by a virus called the varicella-zoster virus (VZV). A rash, which starts as small itchy red spots, can sometimes cover the whole body. Streptococcus bacteria can cause skin, throat and inner ear infections.

4. Helping the body’s natural defences Antibodies Some white blood cells make proteins called antibodies. These target and destroy specific pathogens. This takes time, but once the body has learned how to make an antibody, it can be rapidly produced in the future. The body has become immune to that disease and won’t get ill. Vaccines make you immune to a disease before you catch it. Changing body chemistry Sometimes the body’s natural defences need help. When the immune system is unable to fight the pathogens effectively, medicinal drugs can often provide this help. They interfere with undesirable chemical reactions happening in the body, often inside cells, on the surface of cells and in body fluids. Proteins, including enzymes, are often involved in this body chemistry and are targets for medicinal drugs. By interfering in places where the body’s natural chemical reactions are not happening properly, medicinal drugs help put the body chemistry right when it goes wrong. Vaccines are usually administered by injection (sometimes called a ‘jab’). This is vaccination. Sometimes more than one vaccine is administered. The MMR jab, for example, protects against measles, mumps and rubella. In the UK, a programme of vaccinations is offered free of charge on the NHS to all babies and children.

5. Medicinal chemistry • Medicinal chemistry • In the early days the main objective of medicinal chemists was to isolate compounds with therapeutic properties from plants. • Nowadays, obtaining potential drugs from plants is still of interest, but medicinal chemistry it concerned primarily with the synthesis of medicinal drugs. • Medicinal chemistry is almost always aimed at drug discovery and development, drawing upon skills, knowledge and understanding of various areas of science, including: • Synthetic organic chemistry • Computational chemistry • Pharmacology (in particular, pharmacokinetics) • Aspects of the biological sciences • Drug discovery and development • Typically, the discovery and development of a new drug: • takes 10 years; • 10,000 new chemical compounds are made; • costs at least £500,000,000.