Pharmacology

Pharmacology

A variety of topics involved with pharmacology, including neuropharmacology, renal pharmacology, human metabolism, intracellular metabolism, and intracellular regulation

Pharmacology (from medicinal properties, they are considered pharmaceuticals.

The field encompasses pharmacy, a health services profession, is concerned with application of the principles learned from pharmacology in its clinical settings; whether it be in a dispensing or clinical care role. In either field, the primary contrast between the two are their distinctions between direct-patient care, for pharmacy practice, and the science-oriented research field, driven by pharmacology.

The origins of

  • American Society for Pharmacology and Experimental Therapeutics.
  • British Pharmacological Society.
  • Pharmaceutical company profiles at NNDB.
  • International Conference on Harmonisation.
  • US Pharmacopeia.
  • International Union of Basic and Clinical Pharmacology.
  • IUPHAR Committee on Receptor Nomenclature and Drug Classification.

External links

  1. ^ Vallance P, Smart TG (January 2006). "The future of pharmacology".  
  2. ^ Brater DC, Daly WJ (May 2000). "Clinical pharmacology in the Middle Ages: principles that presage the 21st century". Clin. Pharmacol. Ther. 67 (5): 447–50.  
  3. ^ Mannfred A. Hollinger (2003)."Introduction to pharmacology". CRC Press. p.4. ISBN 0-415-28033-8
  4. ^ a b Rang HP (January 2006). "The receptor concept: pharmacology's big idea". Br. J. Pharmacol. 147 Suppl 1 (S1): S9–16.  
  5. ^ Maehle AH, Prüll CR, Halliwell RF (August 2002). "The emergence of the drug receptor theory". Nat Rev Drug Discov 1 (8): 637–41.  
  6. ^ Rang, H.P.; M.M. Dale, J.M. Ritter, R.J. Flower (2007). Pharmacology.  
  7. ^ Fareed, M., Afzal, M (2013) "Single nucleotide polymorphism in genome-wide association of human population: A tool for broad spectrum service". Egyptian Journal of Medical Human Genetics 14: 123–134. http://dx.doi.org/10.1016/j.ejmhg.2012.08.001.
  8. ^ Rahman, SZ; Khan, RA (Dec 2006). "Environmental pharmacology: A new discipline". Indian J Pharmacol. 38 (4): 229–30.  
  9. ^ Ilene Sue Ruhoy, Christian G. Daughton. Beyond the medicine cabinet: An analysis of where and why medications accumulate. Environment International 2008, Vol. 34 (8): 1157–1169
  10. ^ James Smith; Viktor Stein (2009). "SPORCalc: A development of a database analysis that provides putative metabolic enzyme reactions for ligand-based drug design". Computational Biology and Chemistry 33 (2): 149–159.  
  11. ^ a b c d e Newton, David; Alasdair Thorpe; Chris Otter (2004). Revise A2 Chemistry.  
  12. ^ Nagle, Hinter; Barbara Nagle (2005). Pharmacology: An Introduction.  

Notes and references

See also

Whereas a pharmacy student will eventually work in a pharmacy dispensing medications, a pharmacologist will typically work within a laboratory setting. Careers for a pharmacologist include academic positions (medical and non-medical), governmental positions, private industrial positions, science writing, scientific patents and law, consultation, biotech and pharmaceutical employment, the alcohol industry, food industry, forensics/law enforcement, and public health or environmental/ecological sciences.

Students of pharmacology must have detailed working knowledge of aspects of physiology, pathology and chemistry. During a typical degree they will cover areas such as (but not limited to) Biochemistry, Biology, Physiology, Genetics, Medical Microbiology and Neuroscience.

Students of pharmacology are trained as Biomedical Scientists, studying the effects of drugs on living organisms. This can lead to new drug discoveries, as well as a better understanding of the way in which the human body works.

Education

The Medicines and Healthcare products Regulatory Agency (MHRA) has a similar role in the UK.

The safety and effectiveness of prescription drugs in the U.S. is regulated by the federal Prescription Drug Marketing Act of 1987.

Gaining FDA approval usually takes several years to attain. Testing done on animals must be extensive and must include several species to help in the evaluation of both the effectiveness and toxicity of the drug. The dosage of any drug approved for use is intended to fall within a range in which the drug produces a therapeutic effect or desired outcome.[12]

  1. The drug must be found to be effective against the disease for which it is seeking approval (where 'effective' means only that the drug performed better than placebo or competitors in at least two trials).
  2. The drug must meet safety criteria by being subject to animal and controlled human testing.

In the United States, the Food and Drug Administration (FDA) is responsible for creating guidelines for the approval and use of drugs. The FDA requires that all approved drugs fulfill two requirements:

Drug legislation and safety

  • Carefully research the demand for their potential new product before spending an outlay of company funds.[11]
  • Obtain a patent on the new medicine preventing other companies from producing that medicine for a certain allocation of time.[11]

As a result of the long time required to develop analogues and test a new medicine and the fact that of every 5000 potential new medicines typically only one will ever reach the open market, this is an expensive way of doing things, often costing over 1 billion dollars. To recoup this outlay pharmaceutical companies may do a number of things:[11]

These new analogues need to be developed. It needs to be determined how safe the medicine is for human consumption, its stability in the human body and the best form for delivery to the desired organ system, like tablet or aerosol. After extensive testing, which can take up to 6 years, the new medicine is ready for marketing and selling.[11]

The metabolic stability and the reactivity of a library of candidate drug compounds have to be assessed for drug metabolism and toxicological studies. Many methods have been proposed for quantitative predictions in drug metabolism; one example of a recent computational method is SPORCalc.[10] If the chemical structure of a medicinal compound is altered slightly, this could slightly or dramatically alter the medicinal properties of the compound depending on the level of alteration as it relates to the structural composition of the substrate or receptor site on which it exerts its medicinal effect, a concept referred to as the structural activity relationship (SAR). This means that when a useful activity has been identified, chemists will make many similar compounds called analogues, in an attempt to maximize the desired medicinal effect(s) of the compound. This development phase can take anywhere from a few years to a decade or more and is very expensive.[11]

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 body that regulates pharmaceuticals is the Food and Drug Administration and they enforce standards set by the United States Pharmacopoeia. In the European Union, the main body that regulates pharmaceuticals is the EMEA and they enforce standards set by the European Pharmacopoeia.

Medicine development and safety testing

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 one) exerts its desired effect at a dose close to its toxic dose. A compound with a wide therapeutic index (greater than five) exerts its desired effect at a dose substantially below its toxic dose. Those with a narrow margin 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 tumors.

  • Liberation – How is the API disintegrated (for solid oral forms (breaking down into smaller particles)), dispersed, or dissolved from the medication?
  • Absorption – How is the API absorbed (through the skin, the intestine, the oral mucosa)?
  • Distribution – How does the API spread through the organism?
  • Metabolism – Is the API converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic?
  • Excretion – How is the API excreted (through the bile, urine, breath, skin)?

When describing the pharmacokinetic properties of the chemical that is the active ingredient or active pharmaceutical ingredient (API), pharmacologists are often interested in L-ADME:

A chemical has, from the pharmacological point-of-view, various properties. Pharmacokinetics describes the effect of the body on the chemical (e.g. half-life and volume of distribution), and pharmacodynamics describes the chemical's effect on the body (desired or toxic).

The study of 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 signaling or metabolic pathways by affecting sites directly on cell-surface receptors (which modulate and mediate cellular signaling pathways controlling cellular function).

Scientific background

Environmental pharmacology is a new discipline.[8] Focus is being given to understand gene–environment interaction, drug-environment interaction and toxin-environment interaction. There is a close collaboration between environmental science and medicine in addressing these issues, as healthcare itself can be a cause of environmental damage or remediation. Human health and ecology are intimately related. Demand for more pharmaceutical products may place the public at risk through the destruction of species. The entry of chemicals and drugs into the aquatic ecosystem is a more serious concern today. In addition, the production of some illegal drugs pollutes drinking water supply by releasing carcinogens.[9] This field is intimately linked with Public Health fields.

Environmental pharmacology

Behavioral pharmacology, also referred to as psychopharmacology, is an interdisciplinary field which studies behavioral effects of psychoactivedrugs. It incorporates approaches and techniques from neuropharmacology, animal behavior and behavioral neuroscience, and is interested in the behavioral and neurobiological mechanisms of action of psychoactive drugs. Another goal of behavioral pharmacology is to develop animal behavioral models to screen chemical compounds with therapeutic potentials. People in this field (called behavioral pharmacologists) typically use small animals (e.g. rodents) to study psychotherapeutic drugs such as antipsychotics, antidepressants and anxiolytics, and drugs of abuse such as nicotine, cocaine, methamphetamine, etc.

Behavioral pharmacology

Pharmacognosy is a branch of pharmacology dealing especially with the composition, use, and development of medicinal substances of biological origin and especially medicinal substances obtained from plants.

Pharmacognosy

Posology is the study of how medicines are dosed. It also depends upon various factors including age, climate, weight, and sex,time of admistrtion .

Posology

Theoretical pharmacology is the study of metrics in pharmacology.

Theoretical pharmacology

Toxicology is the study of the adverse effects, molecular targets, and characterization of drugs or any chemical substance in excess (including those beneficial in lower doses).

Toxicology

Pharmacoepidemiology is the study of the effects of drugs in large numbers of people.

Pharmacoepidemiology

Identification of the genetic basis for polymorphic expression of a gene is done through intronic or exomic single-nucleotide polymorphisms (SNPs) which abolishes the need for different mechanisms for explaining the variability in drug metabolism. SNPs based variations in membrane receptors lead to multidrug resistance (MDR) and the drug–drug interactions. Even drug induced toxicity and many adverse effects can be explained by GWA studies. The multitude of SNPs help in understanding gene pharmacokinetic (PK) or pharmacodynamic (PD) pathways.[7]

Pharmacogenomics is the application of genomic technologies to drug discovery and further characterization of older drugs.

Pharmacogenomics

Pharmacogenetics is clinical testing of genetic variation that gives rise to differing response to drugs.

Pharmacogenetics

Psychopharmacology is the study of the effects of medication on the psyche, observing changed behaviors of the body and mind, and how molecular events are manifest in a measurable behavioral form.

Psychopharmacology

Neuropharmacology is the study of the effects of medication on central and peripheral nervous system functioning.

Neuropharmacology

Clinical pharmacology is the basic science of pharmacology with an added focus on the application of pharmacological principles and methods in the medical clinic and towards patient care and outcomes.

Clinical pharmacology

The discipline of pharmacology can be divided into many sub disciplines each with a specific focus.

Divisions

Contents

  • Divisions 1
    • Clinical pharmacology 1.1
    • Neuropharmacology 1.2
    • Psychopharmacology 1.3
    • Pharmacogenetics 1.4
    • Pharmacogenomics 1.5
    • Pharmacoepidemiology 1.6
    • Toxicology 1.7
    • Theoretical pharmacology 1.8
    • Posology 1.9
    • Pharmacognosy 1.10
    • Behavioral pharmacology 1.11
    • Environmental pharmacology 1.12
  • Scientific background 2
  • Medicine development and safety testing 3
  • Drug legislation and safety 4
  • Education 5
  • See also 6
  • Notes and references 7
  • External links 8

Early pharmacologists focused on natural substances, mainly plant extracts. Pharmacology developed in the 19th century as a biomedical science that applied the principles of scientific experimentation to therapeutic contexts.[6] Today Pharmacologists harness the power of genetics, molecular biology, chemistry, and other advanced tools to transform information about molecular mechanisms and targets into therapies directed against disease, defects or pathogens, and create methods for preventative care, diagnostics, and ultimately personalized medicine.

[4] in 1847, in recognition of the need to understand how therapeutic drugs and poisons produced their effects.Rudolf Buchheim The first pharmacology department was set up by [5]