Toxicology is largely a subset of Pharmacology and is sometimes defined as Overdose Pharmacology.

The rules of causation are possibly more elegant in pharmacology than in any other science. is the study of how drugs act, from the submicroscopic molecular level to statistical investigations of the effects of drugs on populations of people - pharmacoepidemiology.

Quantitative causation

Life scientists, unlike physicians not engaged in research, systematically quantitate results for statistical significance. It is second nature to be familiar with chance associations and the unbiquitous 'noise' that can obscure or occasionally mimic true signals.

In another sense, causation by a drug is typically quantitative in terms of the dose or concentration of drug required to cause an efffect.

A Pharmacologist is a scientist. A physician uses drugs and diagnoses diseases using principles of pharmacology. But it is the scientist who discovers how drugs cause their actions; it is the pharmacologist who quantitates causation by analyzing the dose-response for therapeutic and toxic effects.

Neuropharmacology encompasses those drugs which act on the centrail nervous system (brain, spinal cord) and peripheral nerves. This includes drugs with therapeutic effects or adverse reactions in anxiety, depression, cognition, bipolar disorder, etc: diseases or effects in the areas of neurology and psychiatry. Neuropharmacology Definition

Neurotoxicology likewise concerns toxic effects of drugs (and other substances) on the nervous system. There is a qualitative aspect (what type of neurotoxic effects are produced?) and a quantitative aspect (what exposure (dose x duration) results in what level of neurotoxic effect?). Neurotoxicology Definition

John Lehmann PhD is the principal of Pharmikos. With a BSc from Caltech and PhD from University of British Columbia, he pursued further postdoctoral training in Paris at Synthelabo and in Baltimore at the Johns Hopkins University School of Medicine. He joined the drug discovery effort at Ciba Geigy (now Novartis) ...