Developing New Drugs

There is constant demand to produce new drugs:

• new painkillers are developed to treat symptoms of the disease but not kill the pathogens
• antiviral drugs drugs are needed to kill the virus but not damage the body's tissue
• new antibiotics are needed as new resistant strains of bacteria develop

Traditionally drugs were extracted from plants and moicroorganisms:

• Digitalis is a heart drug that originates with foxgloves
• Aspirin is a pain killer that originates from willow
• Penicillan waxs dicovered by Alexander Fleming from the Penicillium mould

Now the most new drugs are synthesised (made) by chemists in the pharmaceutical industry. However, the starting point may still be a chemical extracted from a plant.

New medical drugs need to be tested and trialled before used to make sure they are safe and not toxic. If a drug is found to be safe, it is tested on patients to:

•  to see if it works
• find out the optimum dosage

After chemists have checked theoretically whether the drugs will or work or not before testing them out on rodents and cells. Once the drugs have passed these tests healthy volunteers try the drug to find the optimum dosage for patients.

These tests on patients are usually double-blind trials:

• some patients are given a placebo, which does not contain the drug, and some patients are given are given the drug
• patients are allocated radomly to the two groups
• neither doctors nor the patientsknow who has recieved a placebo and who has recieved the drug

The purpose of a double-blind triual is to ensure that it is completely fair. If that patients or doctors knew whether it was the drug or the placebo being used, it might influence the outcome of the results.