My Sandbox

Put together a page on Mitochondrial inheritance. Bartimaeus 23:43, 10 November 2005 (UTC)

Ames test needs a lot of work. Bartimaeus 07:18, 16 November 2005 (UTC)

articles in need of my attention

COX, Peroxynitrite, Heroin, Nitrates, Nitrate tolerance, Furosemide, Glucuronidation, Probenecid.

Coronary heart disease add pharmacotherapy.

Pharmacology

Pharmacology (in Greek: pharmacon (φάρμακον) is drug, and logos (λόγος) is science) is the study of how chemical substances interact with living systems. If these substances have medicinal properties, they are referred to as pharmaceuticals. The field encompasses drug composition, drug properties, interactions, toxicology, and desirable effects that can be used in therapy of diseases.

Development of medication is a vital concern to medicine, but also has strong economical and political implications. To protect the consumer and prevent abuse, many governments regulate the manufacture, sale, and administration of medication. In the United States, the main regulatory body is the Food and Drug Administration through its publication of the USP.

Pharmacology as a science is practiced by pharmacologists. Subdisciplines are clinical pharmacology (the medical field of medication effects on humans), neuro- and psychopharmacology (effects of medication on behavior and nervous system functioning), and theoretical pharmacology.

Scientific background

The study of medicinal chemicals requires intimate knowledge of the biological system affected. With the knowledge of cell biology and biochemistry increasing, the field of pharmacology has also changed substantially. It has become possible, through molecular analysis of receptors, to design chemicals that act on specific cellular signalling or metabolic pathways by affecting sites directly on cell-surface receptors (which modulate and mediate cellular signalling pathways controlling cellular function).

A chemical has, from the pharmacological point-of-view, various properties. Pharmacokinetics describes its behaviour in the body - particularly in the blood (e.g. its half-life and volume of distribution), and pharmacodynamics relates its behaviour in the blood to its effects (desired effects or toxic side-effects).

When describing the pharmacokinetic properties of a chemical, pharmacologists are often interested in ADME:

Absorption - How is the medication absorbed (through the skin, the intestine, the oral mucosa)?
Distribution - How does it spread through the organism?
Metabolism - Is the medication converted chemically inside the body, and into which substances. Are these active? Could they be toxic?
Excretion - How is the medication eliminated (through the bile, urine, breath, skin)?

Medication is said to have a narrow or wide therapeutic index or therapeutic window. This describes the ratio of desired effect to toxic effect. A compound with a narrow therapeutic index (close to 1) exerts its desired effect at a dose close to its toxic dose. A compound with a wide therapeutic index (greater than 5) exerts its desired effect at a dose substantially below its toxic dose. Those with a narrow window are more difficult to dose and administer, and may require therapeutic drug monitoring (examples are warfarin, some antiepileptics, aminoglycoside antibiotics). Most anti-cancer drugs have a narrow therapeutic margin: toxic side-effects are almost always encountered at doses used to kill tumours.

Classification

Medication can be usually classified in various ways, e.g. by its chemical properties, mode of administration, or biological system affected. An elaborate and widely used classification system is the Anatomical Therapeutic Chemical Classification System.