Allopurinol

Structural formula
Tautomers of allopurinol
General
Non-proprietary name	Allopurinol
other names	1 H -pyrazolo [3,4- d ] pyrimidin-4-one ( IUPAC )
Molecular formula	C 5 H 4 N 4 O
Brief description	white solid
External identifiers / databases
CAS number 315-30-0 EC number 206-250-9 ECHA InfoCard 100.005.684 PubChem 2094 DrugBank DB00437 Wikidata Q412486
Drug information
ATC code	M04 AA01
Drug class	Uricostatics
Mechanism of action	Xanthine oxidase - inhibitor
properties
Molar mass	136.11 g · mol -1
Melting point	> 350 ° C
solubility	Water: 569 mg l −1 (25 ° C)
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed GHS labeling of hazardous substances danger H and P phrases H: 301-317 P: 280-301 + 310
Toxicological data	78 mg kg −1 ( LD 50 ,  mouse ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The drug Allopurinol in pure form on a porcelain surface

Allopurinol is a drug used to treat chronic gout and in combination with other drugs for leishmaniasis . The active ingredient allopurinol was added to the list of indispensable drugs of the World Health Organization by the World Health Organization (WHO) in 1977.

pharmacology

Allopurinol prevents the breakdown of purines into uric acid by inhibiting the enzyme xanthine oxidase and is therefore also known as a uricostatic . It causes the uric acid level in the blood to drop, which means that uric acid deposits in the tissue can be broken down and make new formation more difficult. The increased uric acid precursors ( xanthines ) can be excreted via the kidneys .

Allopurinol is usually a well-tolerated drug. Due to the potential side effects , however, it should only be taken if prescribed by a doctor and checked. The indication for therapy with allopurinol is given for hyperuricemia > 8.5 mg / dl or for repeated gout attacks , existing gout nephropathy or the presence of uric acid stones. If renal insufficiency is already present , the dose must be adjusted to the remaining renal performance.

unwanted effects

The main undesirable effects are:

• allergic reactions (especially skin reactions)
• Nausea and vomiting
• Blood formation disorders ( leukopenia )
• Kidney stone formation (especially if you drink too little)
• Liver damage
• Polyneuropathy
• Allopurinol hypersensitivity syndrome ( metabolic idiosyncrasy , mortality approx. 30%) with the following symptoms:
  • allergy-like (allergic) symptoms with fever and rash
  • Kidney dysfunction up to anuria
  • massive liver cell death
  • Leukocytosis and eosinophilia
• Stevens-Johnson syndrome , up to the maximum variant as toxic epidermal necrolysis (Lyell syndrome)

Interactions

• If allopurinol concurrently with purine antimetabolites such as azathioprine or 6-mercaptopurine taken, the dose should be reduced to 25% of the usual because allopurinol and its active metabolite oxypurinol the xanthine oxidase inhibiting, resulting to reduced degradation and accumulation of azathioprine.

• Effect enhancement also with:
  • Coumarin- type anticoagulants ( Warfarin Marcumar ). As a result, more frequent blood coagulation controls are necessary, and dose reduction if necessary
  • Probenecid
  • Chlorpropamide
  • Phenytoin
  • theophylline for high doses of allopurinol
  • Ciclosporin

• with sulfinpyrazone, probenecid, benzbromarone, salicylates in high doses the effectiveness of allopurinol is reduced

• with cytostatic drugs there are more frequent changes in the blood count (therefore blood count checks in short time intervals)

Trade names

Monopreparations

Bleminol (D), Cellidrin (D, CH), Epidropal (D), Foligan (D), Gewapurol (A), Gichtex (A), Mephanol (CH), Purinol (A), Remid (D), Uribenz (D ), Uriconorm (CH), Urosin (A), Zyloric (D, A, CH), numerous generics (D, A, CH)

Combination preparations

Allobenz (A), Allo.comp (D), Gichtex plus (A), ViaSpan organ preservation solution (A)

Individual evidence

1. ↑ Allopurinol data sheet at AlfaAesar, accessed on December 15, 2010 ( PDF )(JavaScript required) .
2. ↑ Entry on allopurinol. In: Römpp Online . Georg Thieme Verlag, accessed on June 14, 2014.
3. ↑ ^{a b} Entry on allopurinol in the ChemIDplus database of the United States National Library of Medicine (NLM) .
4. ↑ ^{a b} Allopurinol data sheet from Sigma-Aldrich , accessed on March 20, 2011 ( PDF ).
5. ^ WHO Model Lists of Essential Medicines: Allopurinol , accessed August 16, 2010.
6. ^ Singer JZ, Wallace SL: The allopurinol hypersensitivity syndrome. Unnecessary morbidity and mortality . In: Arthritis and Rheumatism . 29, No. 1, January 1986, pp. 82-87. PMID 3947418 .
7. ↑ Gutiérrez-Macías A, Lizarralde-Palacios E, Martínez-Odriozola P, Miguel-De la Villa F: Fatal allopurinol hypersensitivity syndrome after treatment of asymptomatic hyperuricaemia . In: BMJ (Clinical Research Ed.) . 331, No. 7517, September 2005, pp. 623-624. PMID 16166134 . PMC 1215560 (free full text).
8. ↑ Technical information (000073-Z923) of the Allopurinol-ratiopharm 100 / 300mg tablets ; 4.5 Interactions with other medicinal products and other forms of interaction; P. 2; Retrieved July 3, 2012.
9. ↑ Red List Online: A30 Interactions Allopurinol. ( Memento of February 12, 2013 in the web archive archive.today ), accessed on July 3, 2012.

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !