Pharmacology    

 

Pharmacology is the science of the interaction between chemical substances and living tissues. If the chemical is primarily beneficial, its study falls under the title therapeutics; if primarily harmful, its study is called toxicology. In either case, pharmacodynamics defines how the material is absorbed by the body, where it acts, what its effect is, and how it is metabolized and excreted.

 

Pharmacologists determine the therapeutic index of drugs, that is, the relative benefit to toxicity at various doses. This helps define the dosage of a drug that will most benefit a sick person. They also study how various conditions affect the excretion of drugs. For example, many drugs are more slowly metabolized in older persons, so these drugs need to be administered less frequently. Because many chemicals are excreted by the kidney, persons with kidney disease may have impaired drug excretion.

 

Doctors who specialize in pharmacology are called clinical pharmacologists. Pharmacists who practice in hospitals also specialize in pharmacology, and they can advise doctors on the optimal use of medicinal drugs.

 

Pharmacy is practice of compounding and dispensing drugs; also the place where such medicinal products are prepared. Pharmacy is an area of materia medica, the branch of medical science concerning the sources, nature, properties, and preparation of drugs. Pharmacists share with the chemical and medical profession responsibility for discovering new drugs and synthesizing organic compounds of therapeutic value. In addition, the community pharmacist is increasingly called upon to give advice in matters of health and hygiene.

 

The cup Hygeia, daughter of Asklepius is the symbol of pharmacy. In antiquity, pharmacy and the practice of medicine were often combined, sometimes under the direction of priests, both men and women, who ministered to the sick with religious rites as well. Many peoples of the world continue the close association of drugs, medicine, and religion or faith. Specialization first occurred early in the 9^th century in the civilized world around Baghdad. It gradually spread to Europe as alchemy, eventually evolving into chemistry as physicians began to abandon beliefs that were not demonstrable in the physical world. Physicians often both prepared and prescribed medicines; individual pharmacists not only compounded prescriptions but manufactured medicaments in bulk lots for general sale. Not until well into the 19^th century was the distinction between the pharmacist as a compounder of medicines and the physician as a therapist generally accepted. Now, in many countries, pharmacists are required to undergo specialized undergraduate education for periods of, on average, three to five years, followed by practical training, before being allowed to practice.

 

rembert dodonaeus 1517 – 1585

was born in Malines in Brussels. He studied medicine at  Leuven University, acquiring his degree in 1540. he than traveled around France, Italy and Germany to meet the eminent physicians of his day. He conducted many autopsies and his record of 54 cases were compiled in Medicinalium Observationum Exempla Rara. He served Maximillian II and his son Rudolf II as court physician. Dodonaeus studied medicinal plants and his works were complied in Cruydtboek (Book on Plants) published in Antwerp.

 

Jan Baptista van HELMONT 1580 – 1644

Belgian doctor and chemist, the first scientist to distinguish between gases and air. He pioneered in experimentation and an early form of biochemistry, called iatrochemistry. Helmont believed that the basic elements of the universe are air and water. He believed that plants are composed only of water and claimed to have proved this theory by planting a willow of known weight in soil of known weight and weighing the willow and the soil five years later. The willow had gained 76.7 kg and the soil had lost practically no weight. He suggested that the willow had gained weight by taking in water alone. For the modern explanation of his experiment ð Photosynthesis

 

Philippus Aureolus paracelsus (Theophrastus Bombastus von Hohenheim) 1493 – 1541

German doctor and chemist. Quarrelsome and vitriolic, Paracelsus defied the medical tenets of his time, asserting that diseases were caused by agents that were external to the body and that they could be countered by chemical substances.

 

Many of his remedies were based on the belief that “like cures like”, and in this respect he was a precursor of homoeopathy.

 

Homoeopathy

Homoeopathy is system of medical practice based on the principle that diseases can be cured by drugs that produce in a healthy person the same pathological effects that are symptomatic of the disease. This doctrine was first formulated by the German doctor Samuel Hahnemann in 1796. Homoeopaths also believe that small doses of a drug are more efficacious than large doses. Although homoeopathy is discounted by most doctors, it is still widely practiced.

 

Homoeopathic diagnosis and therapy treats the whole body as a unified organism. Its basis lies in the 19^th century, when Samuel Hahnemann defined disease as “an aberration from the state of health”, which cannot be mechanically removed from the body. In 1881 Hahnemann called for healing to be quick, reliable, and permanent and he believed that holistic medicine embraced all of these attributes. Disease was considered to be of two types: acute, which temporarily disabled the person but which could be overcome with time and treatment, and chronic conditions, a series of acute episodes that could with time seriously disable the patient. In treating acute illness, the homoeopath is charged with four responsibilities: a thorough knowledge of the disease, its etiology, pathology, prognosis, and diagnosis; a thorough knowledge of the medicinal power of drugs; the ability to relate the power of drugs to the patient's condition; an ability to foresee barriers between the patient and good health and a knowledge of how to reduce such barriers.

 

The treatment prescribed by the homoeopathic doctor is largely based on the idea that the body contains a vital natural force which has the power to affect recovery. The basis of homoeopathy adheres to four basic laws. “SIMILIA SIMILIBUS CURENTUR” The law of similar, “like cures like”; a drug that produces symptoms of a disease in a healthy person will cure a person who has the disease. Significantly, this does not have a sound basis in conventional pharmacology. The law of potentiation maintains that high doses of medicine intensify disease symptomatology, whereas small doses tend to strengthen the body's defense mechanisms. There-fore a cure does not lie in the quantity of medicine but in its quality, and invariably in subtle aspects of the curative treatment. This is why most homoeopathic remedies used today require elaborate prescription and formulation regimes. The law of cure occurs from above downwards, from within outwards, from an important organ to a less important one, and in the reverse order of the symptoms. Single remedy medication consists of one pure drug at a time, never in mixtures that could potentially contain harmful compounds.

 

The modern pharmacist deals with complex pharmaceutical remedies far different from the elixirs, spirits, and powders described in the Pharmacopoeia of London 1618 and the Pharmacopoeia of Paris 1639. Most countries with a regulated health-care system prepare a compendium, or formulary, of authorized drugs and formulae.

  

The First Anti-Infective Drugs

The first drug to cure an often fatal infectious disease was the “magic bullet” of the German bacteriologist Paul Ehrlich. Convinced that arsenic provided the clue to a cure for the venereal disease syphilis, Ehrlich synthesized hundreds of organic arsenical compounds. These he injected into mice previously infected with the causative organism, Spirochaete pallidum. Some of the 605 compounds tested showed some promise of success but too many mice died. In 1910 Ehrlich made and tested compound number 606, arsphenamine. It cured his infected mice and, more importantly, left them in good health.

 

Ehrlich now had the problem of making his compound in quantity, suitably packaged for injection, and distributing it for use. He sought the help of the Frankfurt chemical company Hoechst AG. They marketed the substance in glass ampoules, each containing a single dose of arsphenamine in powder form, to be dissolved in sterile water prior to injection. Exported worldwide, it was given the trade name Salvarsan. This process of discovery, commercial production, and distribution has remained a pattern for the pharmaceutical industry to the present day.

Cancellation of F.W. Sertürner, who discovered Morphine