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 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. Clinical pharmacology is the medical field of 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 enzymes, to design chemicals that act on specific molecular pathways.

A chemical has, from the pharmacological point-of-view, various properties. Pharmacokinetics is its fate (e.g. its half-life and volume of distribution) in the organism, and pharmacodynamics is its mode of action and potential toxicity.

When describing the pharmacokinetic properties of a chemical, a pharmacologist employs the ADME principle:

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, and into which substances. Are these active? Could they be toxic?

Excretion - How is the medication eliminated (through the bile, urine, skin)?

Medication is said to have a narrow or wide therapeutic margin or therapeutic window. 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).

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.

Types of medication

For the gastrointestinal tract or digestive system

Upper digestive tract: antacids, reflux suppressants, antiflatulents, antidopaminergics, proton pump inhibitors, H2-receptor antagonists, cytoprotectants, prostaglandin analogues

Lower digestive tract: laxatives, antispasmodics, antidiarrhoeals, bile acid sequestrants, opioids

For the cardiovascular system

General: beta-receptor blocker, calcium channel blockers, diuretics, cardiac glycosides, antiarrhythmics, nitrate, antianginals, vasoconstrictor, vasodilator, peripheral activator

Affecting Blood pressure: ACE inhibitors, angiotensin receptor blockers, alpha blocker

Coagulation: anticoagulant, heparin, antiplatelet drug, fibrinolytic, anti-hemophilic factor, haemostatic drugs

Atherosclerosis/cholesterol agents: hypolipidaemic agents, statins.

For the eye

General: astringent, adrenergic neurone blocker, ocular lubricant

Diagnostic: topical anesthetics, sympathomimetics, parasympatholytics, mydriatics, cycloplegics

Anti-bacterial: antibiotics, topical antibiotics, sulfa drugs, aminoglycosides, fluoroquinolones

Anti-viral:

Anti-fungal:

Anti-inflammatory: NSAIDs, corticosteroids

Anti-allergy: mast cell inhibitors

Anti-glaucoma: adrenergic agonists, beta-blockers, carbonic anhydrase inhibitors/hyperosmotics, cholinergics, miotics, parasympathomimetics, prostaglandin agonists/prostaglandin inhibitors

For the ear, nose and oropharynx

sympathomimetic, antihistamine, anticholinergic, NSAIDs, steroid, antiseptic, local anesthetic, antifungal, cerumenolytic

For the respiratory system

bronchodilator, NSAIDs, anti-allergic, antitussive, mucolytic, decongestant corticosteroid, beta-receptor antagonist, anticholinergic, steroid

For endocrine problems

androgen, antiandrogen, gonadotropin, corticosteroid, growth hormone, insulin, antidiabetic (sulfonylurea, biguanide/metformin, thiazolidinedione, insulin), thyroid hormones, antithyroid drugs, calcitonin, diphosponate, vasopressin analogues

For the reproductive system or urinary system

antifungal, alkalising agent, quinolones, antibiotic, cholinergic, anticholinergic, anticholinesterase, antispasmodic, 5-alpha reductase inhibitor, selective alpha-1 blocker, sildenafil

For contraception

contraceptive, oral contraceptives, spermicide, depot contraceptives

For obstetrics and gynaecology

NSAIDs, anticholinergic, haemostatic drug, antifibrinolytic, Hormone Replacement Therapy, bone regulator, beta-receptor agonist, follicle stimulating hormone, luteinising hormone, LHRH
gamolenic acid, gonadotropin release inhibitor, progestogen, dopamine agonist, oestrogen, prostaglandin, gonadorelin, clomiphene, tamoxifen, Diethylstilbestrol

For the skin

emollient, anti-pruritic, antifungal, disinfectant, scabicide, pediculicide, tar products, vitamin A derivatives, vitamin D analogue, keratolytic, abrasive, systemic antibiotic, topical antibiotic, hormones, desloughing agent, exudate absorbent, fibrinolytic, proteolytic, sunscreen, antiperspirant

For infections and infestations

antibiotic, antifungal, antileprotic, antituberculous drug, antimalarial, anthelmintic, amoebicide, antiviral, antiprotozoal, antiserum

For immunology

vaccine, immunoglobulin, immunosuppressant, interferon, monoclonal antibody

For allergic disorders

anti-allergic, antihistamine, NSAIDs

For nutrition

tonic, iron preparation, electrolyte, parenteral nutritional supplement, vitamins, anti-obesity drug, anabolic drug, haematopoietic drug, food product drug

For neoplastic disorders

cytotoxic drug, sex hormones, aromatase inhibitor, somatostatin inhibitor, recombinant interleukins, G-CSF, erythropoietin

For diagnostics

contrast media

For euthanasia

A euthanaticum is used for euthanasia and physician-assisted suicide, see also barbiturates.

External links

International Conference on Harmonisation

US Pharmocopea

Pharmacology

Pharmacology

Scientific background

Classification

Types of medication

For the gastrointestinal tract or digestive system

For the cardiovascular system

For the central nervous system

For pain & consciousness (Anaesthetic drugs)

For musculo-skeletal disorders

For the eye

For the ear, nose and oropharynx

For the respiratory system

For endocrine problems

For the reproductive system or urinary system

For contraception

For obstetrics and gynaecology

For the skin

For infections and infestations

For immunology

For allergic disorders

For nutrition

For neoplastic disorders

For diagnostics

For euthanasia

External links

See also