History of Pharmacology

Botanical beginnings

Students of the Edinburgh Medical School were taught about drugs as early as 1676. At this time most drugs were effectively herbal remedies, extracted from plants and animals, and it was appropriate for the subject to be taught by a Professor of Botany. In 1738, however, Dr Charles Alston was appointed Professor of both Botany and Materia medica; at this time students were expected to know the properties of 250 plants, 60 minerals, various gums and resin, and also extracts of snails, worms and vipers used as medicines. Dr John Hope succeeded Aston as Professor of Botany and Materia medica in 1761, and introduced the Linneaen system of classifying plants.

Establishing the Chair of Materia Medica

It was in 1768 that Materia Medica (Pharmacology) separated from Botany, and Francis Home was appointed the first Professor of Materia medica and Head of Department. His notable achievements included issuing the order, while an army surgeon in Flanders, that “the troops should drink no water without it first being boiled and a little brandy or gin be mixed with it”, and was the first to show that sugar in diabetic urine is fermented by yeast. Francis Home was succeeded by James Home, his son.

Andrew Duncan (junior) followed and wrote the Edinburgh New Dispensatory, an influential textbook of the time. Robert Christison succeeded to the Chair in 1832 and specialised in toxicology. He worked on the toxic effects of arsenic, and its detection in the corpse, oxalic acid, laburnum, cyanides, alcohol, and many other poisons; he gave evidence at the trial of Burke and Hare having carried out experiments to show that bruises on corpses sold could not have been caused after death. Christison was Professor of Materia medica for 46 years, and retired in 1877.

Pioneering research

Thomas Fraser, a former pupil of Christison, was appointed Professor of Materia medica and the Chair of Clinical Medicine in 1877, with the support of a number eminent scientists including Sydney Ringer, Paul Bert, E. Vulpian, Carl Ludwig and Oswald Schmiedeberg. Fraser’s contribution to Pharmacology was described as epoch making by the then Chair of Materia medica at Berlin. In 1872 he presented two lectures to the Royal College of Physicians, which were later published in the British Medical Journal. The first lecture related the chemical properties of active substances to their physiological actions, while the second dealt with antagonism. He was perhaps the first to state that as active substances affect different areas of the body “there must undoubtedly be some difference between the chemical properties of each of the structures influenced”, i.e., there must be receptors for active substances.

In 1918 Arthur Cushny succeeded Fraser at Edinburgh, when he moved from University College London where he had been appointed as their first Professor of Pharmacology in 1908, to take up the Chair of Materia medica at Edinburgh. Cushny developed much of our understanding of the mechanism of action of digoxin (extracted from foxglove) against heart failure. He also provided the first example of “pharmacological fact” by demonstrating that one optical isomer (laevorotatory) of a drug, adrenaline, was more active than the other (dextrorotatory).

Innovation and discovery

Cushny was succeeded by Alfred (AJ) Clark in 1926. AJ Clark's pioneering studies on the chemistry of drug action established him as the father of the modern Pharmacology. His classic textbook on the subject, “Applied Pharmacology”, ensured the continuation of discovery and innovation in the field of Pharmacology at the University of Edinburgh. Clark provided the first quantitative study of drug action; he described the now familiar ‘parallel shift’ of the “dose”-response curve produced by a competitive antagonist.

Sir John Gaddum, a renowned neuro-pharmacologist and author of “Gaddum’s Textook of Pharmacology”, was appointed to the Chair in 1942, and developed further our understanding of drug action by deriving, for the first time, the equations that described the binding of two mutually exclusive compounds at the same population of receptor sites. These represent perhaps two of the three most significant advances in modern quantitative pharmacology, the third being the extension of these equations by Schild at King’s College London, which revolutionised approaches to drug development.  

Sir John Gaddum was succeeded by Lord (Walter) Perry in 1958, who continued to build up the strength of the Department and to diversify it’s interests, and provided experimental confirmation of the role of acetylcholine in synaptic transmission at the parasympathetic ganglia. He left Edinburgh to become the founding Vice Chancellor of the Open University. In 1998 he chaired the inquiry established by the Lords' committee on science and technology into the medical uses of cannabis, which recommended that the government allow doctors to prescribe cannabis. He said: "We have seen enough evidence to convince us that a doctor might legitimately want to prescribe cannabis to relieve pain or the symptoms of multiple sclerosis, and that the criminal law ought not to stand in the way."

Eric Horton, a former pupil of Gaddum, succeeded to the Chair in 1969, placing Edinburgh at the forefront of investigations on the therapeutic pathways, specifically prostaglandins, that could be targeted in the treatment of pain and inflammation. Horton was succeeded by Bernard L. Ginsborg in 1980, who described the contribution of flickering eye movement to vision, voltage-gated calcium currents, pre-synaptic inhibitory ATP and adenosine receptors, and store-depletion activated calcium entry.

From 1985 the Chair of Pharmacology was held by John S. Kelly, who oversaw great advances in our understanding of neuroreceptor mechanisms in the brain, spanning cholinergic, glutamatergic and serotoninergic systems.