Colchicane has a narrow therapeutic window and is extremely toxic in overdose. Patients at particular risk of toxicity are those with renal or hepatic impairment, gastrointestinal or cardiac disease, and patients at extremes of age.
Following Colchicane overdose, all patients, even in the absence of early symptoms, should be referred for immediate medical assessment.
Clinical:
Symptoms of acute overdosage may be delayed (3 hours on average): nausea, vomiting, abdominal pain, hemorrhagic gastroenteritis, volume depletion, electrolyte abnormalities, leukocytosis, hypotension in severe cases. The second phase with life threatening complications develops 24 to 72 hours after drug administration: multisystem organ dysfunction, acute renal failure, confusion, coma, ascending peripheral motor and sensory neuropathy, myocardial depression, pancytopenia, dysrhythmias, respiratory failure, consumption coagulopathy. Death is usually a result of respiratory depression and cardiovascular collapse. If the patient survives, recovery may be accompanied by rebound leukocytosis and reversible alopecia starting about one week after the initial ingestion.
Treatment:
No antidote is available.
Elimination of toxins by gastric lavage within one hour of acute poisoning.
Consider oral activated charcoal in adults who have ingested more than 0.1mg/kg bodyweight within 1 hour of presentation and in children who have ingested any amount within 1 hour of presentation.
Haemodialysis has no efficacy (high apparent distribution volume).
Close clinical and biological monitoring in hospital environment.
Symptomatic and supportive treatment: control of respiration, maintenance of blood pressure and circulation, correction of fluid and electrolytes imbalance.
The lethal dose varies widely (7-65 mg single dose) for adults but is generally about 20 mg.
Colchican has a narrow therapeutic window and is extremely toxic in overdose. Patients at particular risk of toxicity are those with renal or hepatic impairment, gastrointestinal or cardiac disease, and patients at extremes of age.
Following Colchican overdose, all patients, even in the absence of early symptoms, should be referred for immediate medical assessment.
Clinical:
Symptoms of acute overdosage may be delayed (3 hours on average): nausea, vomiting, abdominal pain, hemorrhagic gastroenteritis, volume depletion, electrolyte abnormalities, leukocytosis, hypotension in severe cases. The second phase with life threatening complications develops 24 to 72 hours after drug administration: multisystem organ dysfunction, acute renal failure, confusion, coma, ascending peripheral motor and sensory neuropathy, myocardial depression, pancytopenia, dysrhythmias, respiratory failure, consumption coagulopathy. Death is usually a result of respiratory depression and cardiovascular collapse. If the patient survives, recovery may be accompanied by rebound leukocytosis and reversible alopecia starting about one week after the initial ingestion.
Treatment:
No antidote is available.
Elimination of toxins by gastric lavage within one hour of acute poisoning.
Consider oral activated charcoal in adults who have ingested more than 0.1mg/kg bodyweight within 1 hour of presentation and in children who have ingested any amount within 1 hour of presentation.
Haemodialysis has no efficacy (high apparent distribution volume).
Close clinical and biological monitoring in hospital environment.
Symptomatic and supportive treatment: control of respiration, maintenance of blood pressure and circulation, correction of fluid and electrolytes imbalance.
The lethal dose varies widely (7-65 mg single dose) for adults but is generally about 20 mg.
-
- Patients with blood dyscrasias
- Pregnancy
- Breastfeeding
- Women of childbearing potential unless using effective contraceptive measures
- Patients with severe renal impairment
- Patients with severe hepatic impairment
- Colchicane should not be used in patients undergoing haemodialysis since it cannot be removed by dialysis or exchange transfusion.
- Colchicane is contraindicated in patients with renal or hepatic impairment who are taking a P-glycoprotein (P-gp) inhibitor or a strong CYP3A4 inhibitor
-
- Patients with blood dyscrasias
- Pregnancy
- Breastfeeding
- Women of childbearing potential unless using effective contraceptive measures
- Patients with severe renal impairment
- Patients with severe hepatic impairment
- Colchican should not be used in patients undergoing haemodialysis since it cannot be removed by dialysis or exchange transfusion.
- Colchican is contraindicated in patients with renal or hepatic impairment who are taking a P-glycoprotein (P-gp) inhibitor or a strong CYP3A4 inhibitor
None known.
The following adverse reactions have been observed.
The frequencies are listed under one of the following classifications:
Very common > 1/10
Common > 1/100 and < 1/10
Uncommon > 1/1000 and < 1/100
Rare > 1/10 000 and < 1/1000
Very rare < 1/10 000
Not known (cannot be estimated from the available data)
Blood and lymphatic system disorders
Not known: bone marrow depression with agranulocytosis, aplastic anaemia and thrombocytopenia.
Nervous system disorders
Not known: peripheral neuritis, neuropathy.
Gastrointestinal system disorders
Common: abdominal pain, nausea, vomiting and diarrhoea.
Not known: gastrointestinal haemorrhage.
Hepatobiliary disorders
Not known: hepatic damage.
Skin and subcutaneous tissue disorders
Not known: alopecia, rash.
Musculoskeletal and connective tissue disorders
Not known: myopathy and rhabdomyolysis.
Renal and urinary disorders
Not known: renal damage.
Reproductive system and breast disorders
Not known: amenorrhoea, dysmenorrhoea, oligospermia, azoospermia.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard.
Genotoxicity
In one study, a bacterial test indicated that Colchicane has a slight mutagenic effect.
However, two other bacterial tests and a test in Drosophila melanogaster found that Colchicane was not mutagenic.
Tests have shown that Colchicane induces chromosomal aberrations and micronuclei, and causes some DNA damage.
Teratogenicity
Tests in animals have shown that Colchicane is teratogenic.
Genotoxicity
In one study, a bacterial test indicated that Colchican has a slight mutagenic effect.
However, two other bacterial tests and a test in Drosophila melanogaster found that Colchican was not mutagenic.
Tests have shown that Colchican induces chromosomal aberrations and micronuclei, and causes some DNA damage.
Teratogenicity
Tests in animals have shown that Colchican is teratogenic.
Adults
- Treatment of acute gout
- Prophylaxis of gout attack during initiation of therapy with allopurinol and uricosuric drugs
Pharmacotherapeutic group: drugs for gout, with no effect on uric acid metabolism. ATC code: M04AC01
In the AGREE (Acute Gout Flare Receiving Colchicane Evaluation) study low- and high-dose Colchicane were compared using a randomized, placebo controlled design. The high-dose prolonged Colchicane regimen (4.8 mg total over 6 hours) was compared with a placebo and a low-dose abbreviated regimen (1.8 mg total over 1 hour, i.e. 1.2 mg followed by 0.6 mg in 1 hour). Both Colchicane regimens were significantly more effective than placebo, with 32.7% responders in the high dose group, 37.8% responders in the low-dose group, and 15.5% responders in the placebo group (P = 0.034 and P = 0.005, respectively, versus placebo). The results at the primary 24hour end point demonstrate superior safety of low dose Colchicane, without loss of efficacy, relative to high dose Colchicane for early acute gout flare (self-administered within 12 hours of flare onset). The pharmacokinetic analysis performed in this study showed that the Colchicane plasma concentration was decreased substantially from about 12 hours after administration in healthy volunteers.
Colchicane prophylaxis (0.6 mg twice daily) during initiation of allopurinol for chronic gouty arthritis reduced the frequency and severity of acute flares, and reduced the likelihood of recurrent flares. Treatment may be continued for up to 6 months, based on clinical data. Prospective randomized controlled trials are needed to further evaluate flare prophylaxis for up to 6 months, after 6 months, and over time.
The mechanism of action of Colchicane in the treatment of gout is not clearly understood. Colchicane is considered to act against the inflammatory response to urate crystals, by possibly inhibiting the migration of granulocytes into the inflamed area. Other properties of Colchicane, such as interaction with the microtubules, could also contribute to the operation. Onset of action is approximately 12 hours after oral administration and is maximal after 1 to 2 days.
Pharmacotherapeutic group: drugs for gout, with no effect on uric acid metabolism. ATC code: M04AC01
In the AGREE (Acute Gout Flare Receiving Colchican Evaluation) study low- and high-dose Colchican were compared using a randomized, placebo controlled design. The high-dose prolonged Colchican regimen (4.8 mg total over 6 hours) was compared with a placebo and a low-dose abbreviated regimen (1.8 mg total over 1 hour, i.e. 1.2 mg followed by 0.6 mg in 1 hour). Both Colchican regimens were significantly more effective than placebo, with 32.7% responders in the high dose group, 37.8% responders in the low-dose group, and 15.5% responders in the placebo group (P = 0.034 and P = 0.005, respectively, versus placebo). The results at the primary 24hour end point demonstrate superior safety of low dose Colchican, without loss of efficacy, relative to high dose Colchican for early acute gout flare (self-administered within 12 hours of flare onset). The pharmacokinetic analysis performed in this study showed that the Colchican plasma concentration was decreased substantially from about 12 hours after administration in healthy volunteers.
Colchican prophylaxis (0.6 mg twice daily) during initiation of allopurinol for chronic gouty arthritis reduced the frequency and severity of acute flares, and reduced the likelihood of recurrent flares. Treatment may be continued for up to 6 months, based on clinical data. Prospective randomized controlled trials are needed to further evaluate flare prophylaxis for up to 6 months, after 6 months, and over time.
The mechanism of action of Colchican in the treatment of gout is not clearly understood. Colchican is considered to act against the inflammatory response to urate crystals, by possibly inhibiting the migration of granulocytes into the inflamed area. Other properties of Colchican, such as interaction with the microtubules, could also contribute to the operation. Onset of action is approximately 12 hours after oral administration and is maximal after 1 to 2 days.
Colchicane is rapidly and almost completely absorbed after oral administration. Maximum plasma concentrations are met usually after 30 to 120 minutes. The terminal half-life is 3 to 10 hours. Plasma protein binding is approximately 30%. Colchicane is partially metabolised in the liver and then in part via the bile. It accumulates in leucocytes. Colchicane is largely excreted (80%) in unchanged form and as metabolites in the faeces. 10-20% is excreted in the urine.
Renal impairment
Colchicane is significantly excreted in urine in healthy subjects. Clearance of Colchicane is decreased in patients with impaired renal function. Total body clearance of Colchicane was reduced by 75% in patients with end-stage renal disease undergoing dialysis.
The influence of renal impairment on the pharmacokinetics of Colchicane was assessed in a study in patients with familial Mediterranean fever (FMF), 5 women and 4 men, with (n=4) and without (n=5) renal impairment. The mean age was 30 years (range 19-42 years). All 5 patients with renal impairment had biopsy-proven amyloidosis; 4 were on routine haemodialysis and 1 had a serum creatinine CL of 15 ml/min. They could therefore be classified as having severe renal impairment. Subjects received 1 mg Colchicane except for 1 subject with cirrhosis who received 500 micrograms. A 4-fold decrease in Colchicane CL was observed in subjects with renal impairment compared to those with normal renal function (0.168 ± 0.063 l/h/kg vs. 0.727 ± 0.110 l/h/kg). The terminal half-life was 18.8 ± 1.2 h for subjects with severe renal impairment and 4.4 ± 1.0 h for those with normal renal function. The volume of distribution was similar between groups. The patient with cirrhosis had a 10-fold lower CL compared to the subjects with normal renal function.
Paediatric population
No pharmacokinetics data are available in children.
Colchican is rapidly and almost completely absorbed after oral administration. Maximum plasma concentrations are met usually after 30 to 120 minutes. The terminal half-life is 3 to 10 hours. Plasma protein binding is approximately 30%. Colchican is partially metabolised in the liver and then in part via the bile. It accumulates in leucocytes. Colchican is largely excreted (80%) in unchanged form and as metabolites in the faeces. 10-20% is excreted in the urine.
Renal impairment
Colchican is significantly excreted in urine in healthy subjects. Clearance of Colchican is decreased in patients with impaired renal function. Total body clearance of Colchican was reduced by 75% in patients with end-stage renal disease undergoing dialysis.
The influence of renal impairment on the pharmacokinetics of Colchican was assessed in a study in patients with familial Mediterranean fever (FMF), 5 women and 4 men, with (n=4) and without (n=5) renal impairment. The mean age was 30 years (range 19-42 years). All 5 patients with renal impairment had biopsy-proven amyloidosis; 4 were on routine haemodialysis and 1 had a serum creatinine CL of 15 ml/min. They could therefore be classified as having severe renal impairment. Subjects received 1 mg Colchican except for 1 subject with cirrhosis who received 500 micrograms. A 4-fold decrease in Colchican CL was observed in subjects with renal impairment compared to those with normal renal function (0.168 ± 0.063 l/h/kg vs. 0.727 ± 0.110 l/h/kg). The terminal half-life was 18.8 ± 1.2 h for subjects with severe renal impairment and 4.4 ± 1.0 h for those with normal renal function. The volume of distribution was similar between groups. The patient with cirrhosis had a 10-fold lower CL compared to the subjects with normal renal function.
Paediatric population
No pharmacokinetics data are available in children.
Colchicane is potentially toxic so it is important not to exceed the dose prescribed by a physician with the necessary knowledge and experience.
Colchicane has a narrow therapeutic window. The administration should be discontinued if toxic symptoms such as nausea, vomiting, abdominal pain, diarrhoea occur.
Colchicane may cause severe bone marrow depression (agranulocytosis, aplastic anaemia, thrombocytopenia). The change in blood counts may be gradual or very sudden. Aplastic anaemia in particular has a high mortality rate. Periodic checks of the blood picture are essential.
If patients develop signs or symptoms that could indicate a blood cell dyscrasia, such as fever, stomatitis, sore throat, prolonged bleeding, bruising or skin disorders, treatment with Colchicane should be immediately discontinued and a full haematological investigation should be conducted straight away.
Caution is advised in case of:
- liver or renal impairment
- cardiovascular disease
- gastrointestinal disorders
- elderly and debilitated patients
- patients with abnormalities in blood counts
Patients with liver or renal impairment should be carefully monitored for adverse effects of Colchicane.
Co-administration with P-gp inhibitors and/or moderate or strong CYP3A4 inhibitors will increase the exposure to Colchicane, which may lead to Colchicane induced toxicity including fatalities. If treatment with a P-gp inhibitor or a moderate or strong CYP3A4 inhibitor is required in patients with normal renal and hepatic function, a reduction in Colchicane dosage or interruption of Colchicane treatment is recommended.
This medicinal product contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Colchican is potentially toxic so it is important not to exceed the dose prescribed by a physician with the necessary knowledge and experience.
Colchican has a narrow therapeutic window. The administration should be discontinued if toxic symptoms such as nausea, vomiting, abdominal pain, diarrhoea occur.
Colchican may cause severe bone marrow depression (agranulocytosis, aplastic anaemia, thrombocytopenia). The change in blood counts may be gradual or very sudden. Aplastic anaemia in particular has a high mortality rate. Periodic checks of the blood picture are essential.
If patients develop signs or symptoms that could indicate a blood cell dyscrasia, such as fever, stomatitis, sore throat, prolonged bleeding, bruising or skin disorders, treatment with Colchican should be immediately discontinued and a full haematological investigation should be conducted straight away.
Caution is advised in case of:
- liver or renal impairment
- cardiovascular disease
- gastrointestinal disorders
- elderly and debilitated patients
- patients with abnormalities in blood counts
Patients with liver or renal impairment should be carefully monitored for adverse effects of Colchican.
Co-administration with P-gp inhibitors and/or moderate or strong CYP3A4 inhibitors will increase the exposure to Colchican, which may lead to Colchican induced toxicity including fatalities. If treatment with a P-gp inhibitor or a moderate or strong CYP3A4 inhibitor is required in patients with normal renal and hepatic function, a reduction in Colchican dosage or interruption of Colchican treatment is recommended.
This medicinal product contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
No details are available regarding the influence of Colchicane on the ability to drive and use machines. However, the possibility of drowsiness and dizziness should be taken into account.
No details are available regarding the influence of Colchican on the ability to drive and use machines. However, the possibility of drowsiness and dizziness should be taken into account.
Posology
Adults
Treatment of acute gout attack:
1 mg (2 tablets) to start followed by 500 micrograms (1 tablet) after 1 hour.
No further tablets should be taken for 12 hours.
After 12 hours, treatment can resume if necessary with a maximum dose of 500 micrograms (1 tablet) every 8 hours until symptoms are relieved.
The course of treatment should end when symptoms are relieved or when a total of 6 mg (12 tablets) has been taken.
No more than 6 mg (12 tablets) should be taken as a course of treatment.
After completion of a course, another course should not be started for at least 3 days (72 hours).
Prophylaxis of gout attack during initiation of therapy with allopurinol and uricosuric drugs:
500 micrograms twice daily.
The treatment duration should be decided after factors such as flare frequency, gout duration and the presence and size of tophi have been assessed.
Patients with renal impairment:
Use with caution in patients with mild renal impairment.).
Patients with hepatic impairment
Use with caution in patients with mild/moderate hepatic impairment. Such patients should be carefully monitored for adverse effects of Colchicane.
Elderly:
Use with caution.
Method of Administration
For oral administration
Tablets should be swallowed whole with a glass of water
Posology
Adults
Treatment of acute gout attack:
1 mg (2 tablets) to start followed by 500 micrograms (1 tablet) after 1 hour.
No further tablets should be taken for 12 hours.
After 12 hours, treatment can resume if necessary with a maximum dose of 500 micrograms (1 tablet) every 8 hours until symptoms are relieved.
The course of treatment should end when symptoms are relieved or when a total of 6 mg (12 tablets) has been taken.
No more than 6 mg (12 tablets) should be taken as a course of treatment.
After completion of a course, another course should not be started for at least 3 days (72 hours).
Prophylaxis of gout attack during initiation of therapy with allopurinol and uricosuric drugs:
500 micrograms twice daily.
The treatment duration should be decided after factors such as flare frequency, gout duration and the presence and size of tophi have been assessed.
Patients with renal impairment:
Use with caution in patients with mild renal impairment.).
Patients with hepatic impairment
Use with caution in patients with mild/moderate hepatic impairment. Such patients should be carefully monitored for adverse effects of Colchican.
Elderly:
Use with caution.
Method of Administration
For oral administration
Tablets should be swallowed whole with a glass of water
None
