Colchicine.

Essay by jordan8900 September 2005

download word file, 1 pages 1.0 1 reviews

Colchicine is a highly poisonous water-soluble alkaloid found in plants of the genus Colchicum (autumn crocus, meadow saffron) with the chemical formula C22H25NO6. The chemical name or common name for colchicine is (S) N-(5,6,7,9-tetrahydro- 1,2,3, IO-tetramethoxy-9-oxobenzo [alpha] heptaien-7-yl) acetamide. The molecular weight of it is 399.2 grams.

Colchicine has 4 isomers,each pair has either R or S configuration.(-)-(aS,7S)-Colchicine is the natural isomer which can interconvert between aR and aS

* C22H25NO6

* molecular weight is 399.4426

* melting point is 142 degrees Celsius

* water solubility is less than 10/g mL at 21 degrees Celsius

* pale yellow to greenish crystalline powder

* photosenstive

* slowly hyrdolyzes in acidic solution

* First used over 2000 years ago

* derived form preparations of Colchicum autumnale

* First described by Padanius Dioscordes (AD 54-68), a Greek surgeon, in De Materia Medica

* currently produced locally by Sigma

Uses:

* Treatment of gout

* Treatment of Familial Mediterranean Fever

* minimally effective chemotherapy agent

* research use as an antimitotic agent

* new uses being explored

- chronic hepatitis B and cirrhosis

- Sweet's syndrome

- pediatric pericarditis

- constipation

Symptoms:

* Nausea

* diarrhea

* pancytopenia

* alopecia

* weakness

* respiratory distress

- potentially fatal

Is divided into 3 phases:

* Stage I is the G.I.

Phase

- occurs within hours of ingestion

* Stage II is the multi-phase stage

- cardiovascular insufficiency

- respiratory insufficiency

- metabolic effects

- neuromuscular effects

- hematologic effects

* Stage III is the recovery phase:

- occurs 7 to 10 days after ingestion

- marked by alopecia

- rebound leukocytosis

Mechanism of toxicity:

* Metabolized in the liver

- facilitated by cytochrome P450

- undergoes deacetylation and hydrolysis

- converted to oxydicolchicine

Recirculated in Liver:

* Significant amount absorbed in the digestive tract...