Biguanide
4036144
217143593
2008-06-04T20:08:10Z
Travisthurston
248002
added common name of Galega
{{Chembox new
|ImageFile=Biguanide.png
|ImageSize=150px
|IUPACName=2-Carbamimidoylguanidine
|OtherNames=Diguanide
|Section1= {{Chembox Identifiers
| CASNo=56-03-1
| PubChem=5939
| SMILES=C(=NC(=N)N)(N)N
}}
|Section2= {{Chembox Properties
| Formula=C<sub>2</sub>H<sub>7</sub>N<sub>5</sub>
| MolarMass=101.11 g/mol
| Appearance=
| Density=
| MeltingPt=
| BoilingPt=
| Solubility=
}}
|Section3= {{Chembox Hazards
| MainHazards=
| FlashPt=
| Autoignition=
}}
}}
[[Image:Metformin.png|thumb|[[Metformin]]]]
[[Image:Buformin.svg|thumb|[[Buformin]]. Note extra [[butane]] at bottom right.]]
[[Image:Phenformin.svg|thumb|[[Phenformin]]. Note extra [[phenyl]] at left.]]
'''Biguanide''' can refer to a molecule, or to a class of drugs based upon this molecule. Biguanides can function as oral antihyperglycemic [[drug]]s used for [[diabetes mellitus]] or [[prediabetes]] treatment. They are also used as [[antimalarial drug]]s.
The disinfectant polyaminopropyl biguanide ([[PAPB]]) features biguanide functional groups.
==Examples==
Examples of biguanides:
* [[Metformin]] - widely used in treatment of [[diabetes mellitus type 2]] combined with obesity
* [[Phenformin]] - withdrawn from the market in most countries due to toxic effects
* [[Buformin]] - withdrawn from the market due to toxic effects
* [[Proguanil]] - an [[antimalarial drug]].
==History==
''[[Galega officinalis]]'' (French lilac) was used for diabetes treatment in traditional medicine for centuries. In the 1920s, guanidine compounds were discovered in ''Galega'' extracts. Animal studies showed that these compunds lowered blood glucose levels. Some less toxic derivatives, [[synthalin]] A and synthalin B, were used for diabetes treatment, but after the discovery of [[insulin]] they were forgotten for the next several decades. Biguanides were reintroduced into Type 2 [[diabetes]] treatment in the late 1950s. Initially [[phenformin]] was widely used, but its potential for sometimes fatal [[lactic acidosis]] resulted in its withdrawal from pharmacotherapy in most pharmacopeias (in the U.S. in [[1977]]). Metformin has a much better safety profile, and it is the principal biguanide drug used in pharmacotherapy worldwide.
==Pharmacotherapy==
Biguanides do not affect the output of insulin, unlike other [[hypoglycemic agent]]s such as [[sulfonylurea]]s and [[meglitinide]]s. Therefore, they are not only effective in Type 2 diabetics, but they can also be effective in Type 1 patients in concert with insulin therapy.
==Mechanism of action==
The exact [[mode of action]] of biguanides is not fully elucidated. However, in hyperinsulinemia, biguanides can lower fasting levels of insulin in plasma. Their therapeutic uses derive from their tendency to reduce [[gluconeogenesis]] in the liver, and as a result, reduces the level of glucose in the blood. Biguanides also tend to make the cells of the body more willing to absorb glucose already present in the blood stream, and there again reducing the level of glucose in the plasma.
==Side effects and toxicity==
The most common side effect is [[diarrhea]] and dyspepsia, occurring in up to 30% of patients. The most important and serious side effect is [[lactic acidosis]]. Phenformin and buformin are more prone to cause acidosis than metformin therefore they have been practically replaced by it. However, when metformin is combined with other drugs (combination therapy), [[hypoglycemia]] and other side effects are possible.
==References==
{{Unreferenced|date=February 2008}}
{{Reflist}}
{{Oral_hypoglycemics}}
{{Antimalarials}}
[[Category:Anti-diabetic drugs]]
[[Category:Guanidines]]