In order to work, medicines have an effect on the body, and these types of chemical often have other undesirable (and sometimes unexpected) side effects. This makes designing safe new medicines particularly difficult.
Many new medicines fail in development because the safety concerns outweigh the benefits of the treatment so, to reduce wasted time and effort, toxicologists join the drug development team early in order to help screen out targets and chemicals that would be ultimately unsafe for use in patients. Later in drug development, toxicologists conduct a series of tests so that they can show regulators that the intended drug is safe to use for its intended application.
Toxicologists are needed throughout the drug development process. Their advice at each stage can help weed out chemicals that won’t be safe enough to use as medicines:
- Early in drug development, computer models can be used to predict toxicity based on knowledge of the intended target and chemical structure or existing knowledge of the properties of the chemical or similar chemicals.
- Once chemists have synthesised potential new drugs, in vitroscreening tests can quickly indicate if the new drug is likely to cause skin or eye irritation or damage DNA.
- Toxicologists can use computer models and in vivo tests to understand whether metabolism within the body is likely to affect the toxicity of the drug.