Typically, the clinical toxicologist is a medically qualified graduate who has specialist knowledge of the adverse effects of drugs and other chemicals in humans – and especially how to treat patients who have been exposed to a toxic substance. Most clinical toxicologists work in hospitals and have close links with university clinical pharmacology departments. Clinical toxicologists are responsible for providing advice on how to treat patients who have been poisoned with a drug or other substance, either accidentally or intentionally. This can be provided as part of the National Poisons Information Service. They are expert in interpreting the results of analyses performed in poisoned patients.