Colchicine appears as odorless or nearly odorless pale yellow needles or powder that darkens on exposure to light. Used to treat gouty arthritis, pseudogout, sarcoidal arthritis and calcific tendinitis. (EPA, 1998)
颜色/状态:
Pale yellow scales or powder; pale yellow needles when crystallized from ethyl acetate
气味:
Odorless or nearly so
溶解度:
At 25 °C, 4.5 g/100 g water
蒸汽压力:
3.2X10-11 mm Hg at 25 °C (est)
稳定性/保质期:
Colchicine able to withstand drying, storage, and boiling.
旋光度:
Specific optical rotation: -429 at 17 °C/D (water, 1.72%); -121 deg at 17 °C/d (concentration by volume = 0.9 g in 100 ml chloroform); max absorption (95% ethanol): 350.5 nm (log epsilon = 4.22), 243 nm (log epsilon = 4.47)
分解:
When heated to decomposition, colchicine emits toxic fumes of carbon monoxide, carbon dioxide, and nitrogen oxides.
Colchicine is found to be metabolized in the liver and demethylated to major metabolites, which include 2-O-demethylcolchicine and 3-O-demethylcolchicine, and one minor metabolite, 10-O-demethylcolchicine (colchiceine). According to in vitro studies, CYP3A4 metabolizes colchicine to 2- and 3-demethylcolchicine.
Colchicine undergoes some hepatic metabolism. Colchicine is partially deacetylated in the liver. Large amounts of colchicine and of its metabolites undergo enterohepatic circulation. This may explain the occurrence of a second plasma peak concentration observed 5 to 6 hours after ingestion.
Three novel conjugation metabolites of colchicine were identified in rat bile facilitated by enhanced on-line liquid chromatography-accurate radioisotope counting. The known 2- and 3-demethylcolchicines (DMCs) underwent O-sulfate conjugation in addition to the previously described O-glucuronidation. 2-DMC was preferably O-glucuronidated, whereas 3-DMC predominantly yielded O-sulfation conjugates, indicating phase II conjugation regiopreferences. Moreover, M1 was identified as a novel glutathione conjugate and a possible biotransformation pathway for its formation was proposed. The known 2-DMC (M6), 3-DMC (M7), 2-DMC glucuronide (M4), and novel 3-DMC sulfate (M3) were confirmed as the major metabolites. ...
Probably hepatic. Although colchicine metabolites have not been identified in humans, metabolism by mammalian hepatic microsomes has been demonstrated in vitro.
Route of Elimination: In healthy volunteers (n=12) 40 - 65% of 1 mg orally administered colchicine was recovered unchanged in urine.
Enterohepatic recirculation and biliary excretion are also postulated to play a role in colchicine elimination.
Half Life: Elimination half-life is approximately 1 hour in healthy subjects, although a study with an extended sampling time reported mean terminal elimination half-life values of approximately 9 to 10.5 hours. Other studies have reported half-life values of approximately 2 hours in patients with alcoholic cirrhosis and approximately 2.5 hours in patients with familial Mediterranean fever.
IDENTIFICATION: Colchicine is an antigout preparations. Colchicine is available as tablets and, in some countries, as injectable solutions. Colchicine is an alkaloid of Colchicum autumnale (autumn crocus, meadow saffron). Colchicum is also present in Gloriosa superba. Colchicine is a pale yellow odorless powder or scales. It darkens on exposure to light. Colchicine is used for acute gout attacks to reduce pain and inflammation. It may be used on long-term basis to prevent or reduce the frequency of attacks. Colchicine is used on long-term basis to prevent fever and recurrent polyserositis. Colchicine is effective in preventing the amyloidosis in this condition. Colchicine has been showed to be effective in the treatment of articular, cutaneous and mucosal symptoms. Colchicine has been used in the treatment of scleroderma and sarcoidosis. HUMAN EXPOSURE: Main risks and target organs: Colchicine exerts a multiorgan toxicity. The main toxic effects are related to the effects of colchicine on cellular division and account for diarrhea, bone marrow depression, alopecia. Other acute effects are hypovolemia, shock, and coagulation disturbances, which may lead to death. Summary of clinical effects: Toxic manifestations appear after a delay of 2 to 12 hours following ingestion or parenteral administration. Symptomatology progresses in three stages: Stage I (Day 1 to 3) gastrointestinal and circulatory phase: Severe gastrointestinal irritation: Nausea, vomiting, abdominal cramps, severe diarrhea. Dehydration, hypovolemia, shock. Cardiogenic shock may occur and may result in death within the first 72 hours. Hypoventilation, acute respiratory distress syndrome. Stage II (Day 3 to 10) bone marrow aplasia phase: Bone marrow aplasia with agranulocytosis. Coagulation disorders with diffuse hemorrhages. Rhabdomyolysis, polyneuritis, myopathy, acute renal failure and infections. Stage III: (After 10 day) recovery phase: Alopecia. Routes of entry: Oral: Oral absorption is the most frequent cause of intoxication. Parenteral: Intoxications after parenteral administration are rare, however, the toxic dose appears to be lower than the oral toxic dose. A fatal bone marrow aplasia in a 70 year-old man after 10 mg intravenous colchicine over 5 days. Intoxication with multisystemic reactions after instillation of colchicine into the penile urethra for treatment of condyloma acuminata. Absorption by route of exposure: Oral: Rapidly absorbed from the gastro-intestinal tract. Peak plasma concentration is reached 0.5 to 2 hours after ingestion. Half time of absorption is 15 minutes. Absorption may be modified by pH, gastric contents, intestinal motility. Colchicine is not totally absorbed. There is an important hepatic first pass effect. Colchicine distributes in a space larger than that of the body. In severe renal or liver diseases the volume of distribution is smaller. Colchicine accumulates in kidney, liver, spleen, gastro-intestinal wall and leucocytes and is apparently excluded in heart, brain, skeletal muscle. Colchicine crosses the placenta and has also been found in maternal milk. Biological half-life by route of exposure: Parenteral: After a single 2 mg intravenous dose the average plasma half-life is 20 minutes. Plasma half-life is increased in severe renal disease (40 min) and decreased in severe hepatic disease (9 min). Oral: After oral administration plasma concentrations reach a peak within 0.5 to 2 hours and afterwards decrease rapidly within 2 hours. The plasma half-life is 60 minutes. Colchicine may remain in tissues for as long as 10 days. Metabolism: Colchicine undergoes some hepatic metabolism. Colchicine is partially deacetylated in the liver. Large amounts of colchicine and of its metabolites undergo enterohepatic circulation. This may explain the occurrence of a second plasma peak concentration observed 5 to 6 hours after ingestion. Elimination by route of exposure: Colchicine is excreted unchanged (10 to 20 percent) or as metabolites. Oral: Urinary excretion amount to 16 to 47% of an administered dose. 50 to 70% of colchicine is excreted unchanged and 30 to 50% as metabolites. 20% of the dose administered is excreted in urine in the first 24 hours and 27.5% in the first 48 hours. Colchicine is detected in urine up to 7 to 10 days after ingestion. Urinary excretion is increased in patients with impaired hepatic function. Bile: 10 to 25% of colchicine is excreted in the bile. Feces: Large amounts of the drug are excreted in the feces. Breast Milk: Colchicine may be eliminated in breast milk. Intravenous: Feces: After intravenous administration 10 to 56% is excreted in the feces within the first 48 hours. Breast Milk: Colchicine may be eliminated in breast milk. Mode of action: Colchicine binds to tubulin and this prevents its polymerization into microtubules. The binding is reversible and the half-life of the colchicine-tubulin complex is 36 hours. Colchicine impairs the different cellular functions of the microtubule: separation of chromosome pairs during mitosis (because colchicine arrests mitosis in metaphase), ameboid movements, phagocytosis. Mitosis blockade accounts for diarrhoea, bone marrow depression and alopecia. Colchicine may have a direct toxic effect on muscle, peripheral nervous system and liver. Inhibition of cellular function does not, however, account for all the organ failures seen in severe overdose. Pharmacodynamics: Gout inflammation is initiated by urate crystals within tissues. The crystals are ingested by neutrophils but this leads to the release of enzymes and the destruction of the cells. Chemotactic factors are released and attract more neutrophils. Colchicine may act by preventing phagocytosis, the release of chemotactic factors and the response of neutrophils. Colchicine has other properties such as antipyretic effects, respiratory depression, vasoconstriction and hypertension. Adults: Oral: The severity and the mortality rate of the poisoning is directly related to the dose ingested. Intravenous: A fatal bone marrow aplasia in a 70-year-old patient is reported. The enhanced toxicity of intravenous colchicine is probably due to the higher bioavailability of colchicine after parenteral administration. Teratogenicity: Colchicine is contraindicated in pregnancy as Down's syndrome and spontaneous abortion have been reported. Colchicine should be discontinued three months prior to conception. Interactions: A case of acute cyclosporin nephrotoxicity induced by colchicine administration has been reported. Colchicine may interfere with cyclosporin pharmacokinetics by increasing cyclosporin plasma levels either by enhancing cyclosporin absorption or by reducing its hepatic metabolism. Main adverse effects: Gastrointestinal symptoms are a common complication of chronic colchicine therapy. Fatal outcomes have been reported after intravenous colchicine therapy. Gastrointestinal: vomiting, diarrhoea, abdominal discomfort, paralytic ileus, malabsorption syndrome with steatorrhea. Hematological: Bone marrow depression with agranulocytosis, acute myelomonocytic leukaemia, multiple myeloma, thrombocytopenia. Neurological: Peripheral neuritis, myopathy and rhabdomyolysis. Dermatological: Allergic reactions are rare urticaria; oedema may be seen. Alopecia has been reported after chronic treatment. Reproductive system: A reversible, complete azoospermia has been reported. Metabolic: Colchicine is capable of producing a reversible impairment of vitamin B12 absorption. Porphyria cutanea tarda has been reported. Others: Hyperglycemia has been reported in a 58-year-old woman who ingested colchicine and developed transient diabetes mellitus has been reported. Hyperlipemia: A transient hyperlipemia has been reported. Hyperuricemia: A transient hyperuricemia has also been noted. Hyperthermia-fever: Occurrence of fever may be relate to an infectious complication, especially during the stage of aplasia. Special risks: Pregnancy: Two cases of Down's syndrome babies have been reported. The obstetric histories of 36 women with familial Mediterranean fever on long-term colchicine treatment between 3 and 12 years have been reported. Seven of 28 pregnancies ended in miscarriage. Thirteen women had periods of infertility. All 16 infants born to mothers who had taken colchicine during pregnancy were healthy. The authors do not advise discontinuation of colchicine before planned pregnancy but recommend amniocentesis for karyotyping and reassurance. Breast-feeding: As colchicine is eliminated in the breast milk breast-feeding should be avoided.
Colchicine inhibits microtubule assembly in various cells, including leukocytes, probably by binding to and interfering with polymerization of the microtubule subunit tubulin. Although some studies have found that this action probably does not contribute significantly to colchicine's antigout action, a recent in vitro study has shown that it may be at least partially involved.
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类无致癌性(未列入国际癌症研究机构IARC清单)。
No indication of carcinogenicity to humans (not listed by IARC).
◉ Summary of Use during Lactation:Long-term prophylactic maternal doses of colchicine up to 1.5 mg daily produce levels in milk that result in the infant receiving less than 10% of the maternal weight-adjusted dosage. The highest milk levels occur 2 to 4 hours after a dose, so avoiding breastfeeding during this time can minimize the infant dose, although some clinicians simply recommend taking the drug after nursing. No adverse effects in breastfed infants have been reported in case series and a case-control study and many experts and professional guidelines consider colchicine safe during breastfeeding in women being treated for familial Mediterranean fever or rheumatic conditions.
◉ Effects in Breastfed Infants:In 4 infants whose mothers were taking 1 to 1.5 mg of colchicine daily prophylactically for familial Mediterranean fever, no apparent effects were noted on clinical follow-up over at least 10 months. The authors also reported that they recalled another 6 women who breastfed their infants for at least 3 months during colchicine therapy (dosage not stated) and follow-up for at least 2 years revealed no clinical or developmental problems.
An infant was breastfed (extent not stated) for 6 months during maternal intake of colchicine 0.6 mg twice daily. No apparent adverse effects were noted.
In a study of mothers who took colchicine during pregnancy, 111 of 181 mothers reported breastfeeding (extent not stated) their infants. None of the infants reportedly had colchicine-related adverse effects.
A case-control study compared 37 women who took colchicine during breastfeeding their 38 infants to a matched control group of 75 mothers who had taken amoxicillin, but were unexposed to colchicine, and their 76 breastfed infants. Telephone follow-up occurred at 6 to 48 months (average 28 months) after the initial inquiry. Among the colchicine-exposed group, 76% of infants were exclusively breastfed and the mean overall duration of breastfeeding was 9.1 months. No increased risk of adverse effects was noted in the colchicine-exposed infants compared to the control infants. Specifically, no differences in gastrointestinal symptoms, or growth and development parameters were seen.
Ten nursing mothers who were being treated with colchicine were reported. None of them had any pathology reported.
A woman was treated with anakinra 100 mg subcutaneously and oral colchicine 1 mg twice daily during pregnancy and postpartum for familial Mediterranean fever while she breastfed her infant (extent not specified). At 9 months of age, the infant’s development was within normal range. The routine vaccination schedule for the baby was being performed on time and there was no history of infection in the infant.
◉ Effects on Lactation and Breastmilk:Rel