Sulfonamide (medicine)


Sulfonamide (medicine)

There are several sulfonamide-based groups of drugs. The original antibacterial sulfonamides (sometimes called simply sulfa drugs) are synthetic antimicrobial agents that contain the sulfonamide group. Some sulfonamides are also devoid of antibacterial activity, e.g., the anticonvulsant sultiame. The sulfonylureas and thiazide diuretics are newer drug groups based on the antibacterial sulfonamides.

Sulfa allergies are common, hence medications containing sulfonamides are prescribed carefully. It is important to make a distinction between sulfa drugs and other sulfur-containing drugs and additives, such as sulfates and sulfites, which are chemically unrelated to the sulfonamide group, and do not cause the same hypersensitivity reactions seen in the sulfonamides.

Function

In bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synthetase, DHPS. DHPS catalyses the conversion of PABA ("para"-aminobenzoate) to dihydropteroate, a key step in folate synthesis. Folate is necessary for the cell to synthesize nucleic acids (nucleic acids are essential building blocks of DNA and RNA), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect.

Folate is not synthesized in mammalian cells, but is instead a dietary requirement. This explains the selective toxicity to bacterial cells of these drugs. These antibiotics are used to treat pneumocystis jiroveci pneumonia, urinary tract infections, shigellosis, and certain protozoan infections.The sulfonamide chemical moiety is also present in other medications that are not antimicrobials, including thiazide diuretics (including hydrochorothiazide, metolazone, and indapamide, among others), sulfonylureas (including glipizide, glyburide, among others), and acetazolamide.

Sulfasalazine, in addition to its use as an antibiotic, is also utilized in the treatment of inflammatory bowel disease.

History

Sulfonamide drugs were the first antimicrobial drugs, and paved the way for the antibiotic revolution in medicine. The first sulfonamide was trade named Prontosil, which is a prodrug. Experiments with Prontosil began in 1932 in the laboratories of Bayer AG, at that time a component of the huge German chemical trust IG Farben. The dye-based drug was discovered by a team under the general direction of Farben executive Heinrich Hoerlein, synthesized by Bayer chemist Josef Klarer and tested under the direction of physician/researcher Gerhard Domagk. The first official communication about the breakthrough discovery was not published until 1935, more than two years after the drug was patented by Klarer and his research partner Fritz Mietzsch. Prontosil was the first medicine ever discovered that could effectively treat a range of bacterial infections inside the body. It had a strong protective action against infections caused by streptococci, including blood infections, childbed fever, and erysipelas, and a lesser effect on infections caused by other cocci. Perplexedly, it had no effect at all in the test tube, exerting its antibacterial action only in live animals. Later it was discovered by a French research team at the Pasteur Institute that the drug was metabolized into two pieces inside the body, releasing from the inactive dye portion a smaller, colorless, active compound called sulfanilamide. The discovery helped establish the concept of "bioactivation" and dashed the German corporation's dreams of enormous profit; the active molecule sulfanilamide (or sulfa) had first been synthesized in 1906 and was widely used in the dye-making industry; its patent had since expired and the drug was available to anyone.

The result was a sulfa craze. For several years in the late 1930s hundreds of manufacturers produced tens of thousands of tons of myriad forms of sulfa. This and nonexistent testing requirements lead to the Elixir Sulfanilamide disaster in the fall of 1937, wherein at least 100 people were poisoned with diethylene glycol. This led to the passage of the Federal Food, Drug, and Cosmetic Act in 1938. As the first and only effective antibiotic available in the years before Penicillin, sulfa drugs continued to thrive through the early years of World War II. They are credited with saving the lives of tens of thousands of patients including Franklin Delano Roosevelt, Jr. (son of President Franklin Delano Roosevelt) (in 1936) and Winston Churchill. Sulfa had a central role in preventing wound infections during the war. American soldiers were issued a first aid kit containing sulfa powder and were told to sprinkle it on any open wound. During the years 1942 to 1943, Nazi doctors conducted sulfanilamide experiments on prisoners in concentration camps.

The sulfanilamide compound is more active in the protonated form, which in case of the acid works better in a basic environment. The solubility of the drug is very low and sometimes can crystalize in the kidneys, due to its first pKa of around 10. This is a very painful experience so patients are told to take the medication with copious amounts of water. Newer compounds have a pKa of around 5-6 so the problem is avoided.

Many thousands of molecules containing the sulfanilamide structure have been created since its discovery (by one account, over 5400 permutations by 1945), yielding improved formulations with greater effectiveness and less toxicity. Sulfa drugs are still widely used for conditions such as acne and urinary tract infections, and are receiving renewed interest for the treatment of infections caused by bacteria resistant to other antibiotics.

Sulpha is an alternate (British English) spelling of the common name for sulfonamide antibiotics.

Preparation

Sulfonamides are prepared by the reaction of a sulfonyl chloride with ammonia or an amine.Certain sulfonamides (sulfadiazine or sulfamethoxazole) are sometimes mixed with the drug trimethoprim, which acts against dihydrofolate reductase.It is also known as Sulfa Powder. It received widespread use in the treatment of wounds during the Second World War.

List of Sulfonamides

* Acetazolamide
* Benzolamide
* Bumetanide
* Celecoxib
* Chlorthalidone
* Clopamide
* Dichlorphenamide
* Dorzolamide
* Ethoxzolamide
* Furosemide
* Hydrochlorothiazide
* Indapamide
* Mafenide
* Mefruside
* Metolazone
* Probenecid
* Sulfacetamide
* Sulfadimethoxine
* Sulfadoxine
* Sulfanilamides
* Sulfamethoxazole
* Sulfasalazine
* Sultiame
* Sumatriptan
* Xipamide

ide effects

Sulfonamides have the potential to cause a variety of untoward reactions, including urinary tract disorders, haemopoietic disorders, porphyria and hypersensitivity reactions. When used in large dose, it may develop a strong allergic reaction. One of the most serious is Stevens Johnson syndrome(or toxic epidermal necrolysis).

Adverse reactions

Approximately 3% of the general population have adverse reactions when treated with sulfonamide antimicrobials. Of note is the observation that patients with HIV have a much higher prevalence, at about 60%cite journal
author=SA Tilles
title=Practical issues in the management of hypersensitivity reactions: sulfonamides
journal=Southern Medical Journal
year=2001
month=Aug
volume=94
issue=8
pages=817–24
] . People who have a hypersensitivity reaction to one member of the sulfonamide class are likely to have a similar reaction to others.

Hypersensitivity reactions are less common in non-antibiotic sulfonamides, and, though controversial, the available evidence suggests those with hypersensitivity to sulfonamide antibiotics do not have an increased risk of hypersensitivity reaction to the non-antibiotic agentscite journal
author=CG Slatore
title=Sulfonamide hypersensitivity
journal=Immunology and Allergy Clinics of North America
year=2004
month=Aug
volume=24
issue=3
pages=477–90,vii
doi=10.1016/j.iac.2004.03.011
] .

Two regions of the sulfonamide antibiotic chemical structure are implicated in the hypersensitivity reactions associated with the class.
* The first is the N1 heterocyclic ring, which causes a type I hypersensitivity reaction.
* The second is the N4 amino nitrogen that, in a stereospecific process, forms reactive metabolites that cause either direct cytotoxicity or immunologic response.

The non-antibiotic sulfonamides lack both of these structurescite journal
author=CC Brackett
title=Likelihood and mechanisms of cross-allergenicity between sulfonamide antibiotics and other drugs containing a sulfonamide functional group
journal=Pharmacotherapy
year=2004
month=Jul
volume=24
issue=7
pages=856–70
doi=10.1592/phco.24.9.856.36106
] .

The most common manifestation of a hypersensitivity reaction to sulfa drugs are rash and hives. However, there are several life-threatening manifestations of hypersensitivity to sulfa drugs, including Stevens-Johnson syndrome, toxic epidermal necrolysis, agranulocytosis, hemolytic anemia, thrombocytopenia, and fulminant hepatic necrosis, among otherscite book
title=Harrison's Principles of Internal Medicine, 13th Ed.
publisher=McGraw-Hill Inc.
date=1994
pages=604
] .

ee also

*Antibiotic
*Timeline of antibiotics
* Elixir Sulfanilamide

References

External links

*http://www.nlm.nih.gov/cgi/mesh/2004/MB_cgi?field=entry&term=Sulfonamides - List of sulfonamides
*http://www.thomashager.net - author of "The Demon under the Microscope," a history of the discovery of the sulfa drugs
*http://www.lung.ca/tb/tbhistory/treatment/chemo.html - A History of the Fight Against Tuberculosis in Canada (Chemotherapy)
*http://www.nobel.se/medicine/laureates/1939/press.html - Presentation speech, Nobel Prize in Physiology and Medicine, 1939
*http://home.att.net/~steinert/wwii.htm - The History of WW II Medicine
*http://www.life.umd.edu/classroom/bsci424/Chemotherapy/AntibioticsHistory.htm - A history of antibiotics


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Sulfonamide — may refer to:* Sulfonamide (chemistry) the sulfonamide functional group (organic chemistry) * Sulfonamide (medicine) the group of sulfonamide antibacterial drugs …   Wikipedia

  • sulfonamide — sul·fon·amide or chiefly Brit sul·phon·amide .səl fän ə .mīd, məd; fō nə .mīd n any of various amides (as sulfanilamide) of a sulfonic acid also SULFA DRUG * * * sul·fon·a·mide (səl fonґə mīd) 1. an organic compound containing the… …   Medical dictionary

  • Sulfonamide (chemistry) — In chemistry, the sulfonamide functional group (also spelt sulphonamide ) is S(=O)2 NH2, a sulfonyl group connected to an amine group.A sulfonamide (compound) is a compound that contains this group. The general formula is RSO2NH2, where R is some …   Wikipedia

  • medicine, history of — Introduction  the development of the prevention and treatment of disease from prehistoric and ancient times to the 20th century. Medicine and surgery before 1800 Primitive (primitive culture) medicine and folklore       Unwritten history is not… …   Universalium

  • medicine — I (New American Roget s College Thesaurus) n. medicament, medication, remedy; therapy, physic; medical profession. II (Roget s IV) n. 1. [The healing profession] Syn. medical men, healers, practitioners, doctors, physicians, surgeons, osteopaths …   English dictionary for students

  • preventive medicine — 1. the branch of medical science that deals with prevention of disease. 2. a medication or other agent used for prophylaxis. [1760 70] * * * Efforts toward disease prevention in the community and the individual. It covers patient interviews and… …   Universalium

  • Su — sulfonamide; supine …   Medical dictionary

  • sulfamethoxazole — A sulfonamide related chemically to sulfisoxazole, with a similar antibacterial spectrum, but a slower rate of absorption from the gastrointestinal tract and urinary excretion. * * * sul·fa·meth·ox·a·zole or chiefly Brit sul·pha·meth·ox·a·zole… …   Medical dictionary

  • sulfasalazine — A sulfonamide (acid azosulfa compound) with a marked affinity for connective tissues, especially for those rich in elastin, used in chronic ulcerative colitis; it is broken down in the body to aminosalicylic acid and sulfapyridine. SYN:… …   Medical dictionary

  • Prontosil — The first sulfa drug to be discovered. Largely of historic interest today. The discovery was made by the great German physician and chemist Gerhard Domagk (1895 1964). In 1925 Domagk was named Lecturer in Pathologic Anatomy (pathology) in the… …   Medical dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.