The dose of colchicine that would induce significant toxicity for an individual is unknown. Fatalities have been reported in patients after ingesting a dose as low as 7 mg over a 4-day period, while other patients have reportedly survived after ingesting more than 60 mg. A review of 150 patients who overdosed on colchicine found that those who ingested less than 0.5 mg/kg survived and tended to have milder adverse reactions, such as gastrointestinal symptoms, whereas those who ingested from 0.5 to 0.8 mg/kg had more severe adverse reactions, including myelosuppression. There was 100% mortality among patients who ingested more than 0.8 mg/kg.
Patients with renal or hepatic impairment should not be given MITIGARE® Â with drugs that inhibit both P-glycoprotein and CYP3A4 inhibitors. Combining these dual inhibitors with colchicine in patients with renal or hepatic impairment has resulted in life-threatening or fatal colchicine toxicity.
Patients with both renal and hepatic impairment should not be given MITIGARE®.
Gastrointestinal disorders are the most common adverse reactions with colchicine. They are often the first signs of toxicity and may indicate that the colchicine dose needs to be reduced or therapy stopped. These include diarrhea, nausea, vomiting, and abdominal pain.
Colchicine has been reported to cause neuromuscular toxicity, which may present as muscle pain or weakness.
Toxic manifestations associated with colchicine include myelosuppression, disseminated intravascular coagulation, and injury to cells in the renal, hepatic, circulatory, and central nervous system. These most often occur with excessive accumulation or overdosage.
The following reactions have been reported with colchicine. These have been generally reversible by interrupting treatment or lowering the dose of colchicine:
Digestive: abdominal cramping, abdominal pain, diarrhea, lactose intolerance, nausea, vomiting
Neurological: sensory motor neuropathy
Dermatological: alopecia, maculopapular rash, purpura, rash
Hematological: leukopenia, granulocytopenia, thrombocytopenia, pancytopenia, aplastic anemia
Hepatobiliary: elevated AST, elevated ALT
Musculoskeletal: myopathy, elevated CPK, myotonia, muscle weakness, muscle pain, rhabdomyolysis
Reproductive: azoospermia, oligospermia
To report SUSPECTED ADVERSE REACTIONS, contact Hikma Americas , Inc. at 1-877-233- 2001 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
MITIGARE® ® (colchicine) capsules are indicated for prophylaxis of gout flares in adults.
Limitations Of UseThe safety and effectiveness of MITIGARE® for acute treatment of gout flares during prophylaxis has not been studied.
MITIGARE® is not an analgesic medication and should not be used to treat pain from other causes.
In healthy adults, MITIGARE® when given orally reached a mean Cmax of 3 ng/mL in 1.3 h (range 0.7 to 2.5 h) after 0.6 mg single dose administration.
Absolute bioavailability is reported to be approximately 45%.
Administration with food has no effect on the rate or extent of colchicine absorption.
Colchicine is not effectively removed by hemodialysis.
DistributionColchicine has a mean apparent volume of distribution in healthy young volunteers of approximately 5 to 8 L/kg. Colchicine binding to serum protein is about 39%, primarily to albumin. Colchicine crosses the placenta and distributes into breast milk.
MetabolismA published in vitro human liver microsome study showed that about 16% of colchicine is metabolized to 2-O-demethylcolchicine and 3-O-demethylcolchicine (2- and 3-DMC, respectively) by CYP3A4. Glucuronidation is also believed to be a metabolic pathway for colchicine.
ExcretionIn a published study in healthy volunteers, 40 to 65% of the total absorbed dose of colchicine (1 mg administered orally) was recovered unchanged in urine. Enterohepatic recirculation and biliary excretion are also believed to play a role in colchicine elimination. Colchicine is a substrate of P-gp and P-gp efflux is postulated to play an important role in colchicine disposition. Elimination half-life in humans was found to be 31 h (range 21.7 to 49.9 h).
0.6 mg capsules - No. 4 Dark Blue/Light Blue Hard Gelatin Capsules printed “West-ward 118” in white ink.
Storage And HandlingMITIGARE® (colchicine) capsules, 0.6 mg are No. 4 Dark Blue/Light Blue Hard Gelatin Capsules printed “West-ward 118” in white ink.
Bottles of 100 capsules
Bottles of 1000 capsules
Store at 20° to 25°C (68° to 77°F).
Protect from light and moisture.
Manufactured for: Hikma Americas , Inc., Memphis, TN 38120. Manufactured by: West-Ward Pharmaceuticals Corp. Eatontown, NJ 07724. Revised: Nov 2015
Included as part of the PRECAUTIONS section.
PRECAUTIONS Fatal OverdoseFatal overdoses, both accidental and intentional, have been reported in adults and children who have ingested colchicine. MITIGARE® should be kept out of the reach of children.
Blood DyscrasiasMyelosuppression, leukopenia, granulocytopenia, thrombocytopenia, pancytopenia, and aplastic anemia have been reported with colchicine used in therapeutic doses.
Interactions With CYP3A4 And P-gp InhibitorsBecause colchicine is a substrate for both the CYP3A4 metabolizing enzyme and the P-glycoprotein efflux transporter, inhibition of either of these pathways may lead to colchicine-related toxicity. Inhibition of both CYP3A4 and P-gp by dual inhibitors such as clarithromycin has been reported to produce life-threatening or fatal colchicine toxicity due to significant increases in systemic colchicines levels. Therefore, concomitant use of MITIGARE® and inhibitors of CYP3A4 or P-glycoprotein should be avoided. If avoidance is not possible, reduced daily dose should be considered and the patient should be monitored closely for colchicine toxicity. Use of MITIGARE® in conjunction with drugs that inhibit both P-gp and CYP3A4 is contraindicated in patients with renal or hepatic impairment.
Neuromuscular ToxicityNeuromuscular toxicity and rhabdomyolysis have been reported from chronic treatment with colchicines in therapeutic doses, especially in combination with other drugs known to cause this effect. Patients with impaired renal function and elderly patients (even those with normal renal and hepatic function) are at increased risk. Once colchicine treatment is ceased, the symptoms generally resolve within 1 week to several months.
Patient Counseling InformationAdvise the patient to read the FDA-approved patient labeling (Medication Guide).
Dosing InstructionsIf a dose of MITIGARE® is missed, advise the patient to take the dose as soon as possible and then return to the normal dosing schedule. However, if a dose is skipped, the patient should not double the next dose.
Fatal OverdoseAdvise the patient that fatal overdoses, both accidental and intentional, have been reported in adults and children who have ingested colchicine. MITIGARE® should be kept out of the reach of children.
Blood DyscrasiasAdvise patients that bone marrow depression with agranulocytosis, aplastic anemia, and thrombocytopenia may occur with MITIGARE®.
Drug And Food InteractionsAdvise patients that many drugs or other substances may interact with MITIGARE® and some interactions could be fatal. Therefore, patients should report to their healthcare provider all of the current medications they are taking, and check with their healthcare provider before starting any new medications, including short-term medications such as antibiotics. Patients should also be advised to report the use of non-prescription medication or herbal products. Grapefruit and grapefruit juice may also interact and should not be consumed during treatment with MITIGARE®.
Neuromuscular ToxicityAdvise patients that muscle pain or weakness, tingling or numbness in fingers or toes may occur with MITIGARE® alone or when it is used with certain other drugs. Patients developing any of these signs or symptoms must discontinue MITIGARE® and seek medical evaluation immediately.
Nonclinical Toxicology Carcinogenesis, Mutagenesis, Impairment Of Fertility CarcinogenesisCarcinogenicity studies of colchicine have not been conducted. Due to the potential for colchicine to produce aneuploid cells (cells with an unequal number of chromosomes), colchicine presents a theoretical increased risk of malignancy.
MutagenesisPublished studies demonstrated that colchicine was negative for mutagenicity in the bacterial reverse mutation assay. However, in vitro chromosomal aberration assays demonstrated the formation of micronuclei following colchicine treatment. Because published studies demonstrated that colchicines induces aneuploidy through the process of mitotic nondisjunction without structural DNA changes, colchicine is not considered clastogenic, although micronuclei are formed.
Impairment Of FertilityThere were no studies of the effects of MITIGARE® on fertility. However, published nonclinical studies have demonstrated that colchicine-induced disruption of microtubule formation affects meiosis and mitosis. Published reproductive studies with colchicine reported abnormal sperm morphology and reduced sperm counts in males, and interference with sperm penetration, second meiotic division, and normal cleavage in females.
Case reports and epidemiology studies in human male subjects on colchicine therapy indicate that infertility from colchicine is rare. A case report indicated that azoospermia was reversed when therapy was stopped. Case reports and epidemiology studies in female subjects on colchicine therapy have not established a clear relationship between colchicine use and female infertility.
Use In Specific Populations Use In PregnancyPregnancy Category C. There are no adequate and well-controlled studies with MITIGARE® in pregnant women. Colchicine crosses the human placenta. Developmental studies in animals were not conducted with MITIGARE® , however published animal reproduction and development studies with colchicine demonstrated embryofetal toxicity, teratogenicity, and altered postnatal development at exposures within or above the clinical therapeutic range. Colchicine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Labor And DeliveryThe effect of colchicine on labor and delivery is unknown.
Use In Nursing MothersColchicine is excreted into human milk. Limited information suggests that infants exclusively breastfed receive less than 10 percent of the maternal weight-adjusted dose. While there are no published reports of adverse effects in breast-feeding infants of mothers taking colchicine, colchicine can affect gastrointestinal cell renewal and permeability. Caution should be exercised and breastfeeding infants should be observed for adverse effects when MITIGARE® is administered to a nursing woman.
Pediatric UseGout is rare in pediatric patients; the safety and effectiveness of MITIGARE® in pediatric patients has not been evaluated in controlled studies.
Geriatric UseBecause of the increased incidence of decreased renal function in the elderly population, and the higher incidence of other co-morbid conditions in the elderly population requiring the use of other medications, reducing the dosage of colchicine when elderly patients are treated with colchicines should be carefully considered.
Renal ImpairmentNo dedicated pharmacokinetic study has been conducted using MITIGARE® in patients with varying degrees of renal impairment. Colchicine is known to be excreted in urine in humans and the presence of severe renal impairment has been associated with colchicine toxicity. Urinary clearance of colchicines and its metabolites may be decreased in patients with impaired renal function. Dose reduction or alternatives should be considered for the prophylaxis of gout flares in patients with severe renal impairment. Colchicine is not effectively removed by hemodialysis. Patients who are undergoing hemodialysis should be monitored carefully for colchicine toxicity.
Hepatic ImpairmentNo dedicated pharmacokinetic study using MITIGARE® Â has been conducted in patients with varying degrees of hepatic impairment. Colchicine is known to be metabolized in humans and the presence of severe hepatic impairment has been associated with colchicine toxicity. Hepatic clearance of colchicine may be significantly reduced and plasma half-life prolonged in patients with chronic hepatic impairment.
Dose reduction or alternatives should be considered for the prophylaxis of gout flares in patients with severe hepatic impairment.
For prophylaxis of gout flares, the recommended dosage of MITIGARE® is 0.6 mg once or twice daily. The maximum dose is 1.2 mg per day.
MITIGARE® is administered orally, without regard to meals.
Pharmacokinetic studies evaluating changes in systemic levels of colchicine when co-administered with CYP3A4 inhibitors in healthy volunteers have been conducted with MITIGARE®. While voriconazole 200 mg BID for 5 days (considered a strong CYP3A4 inhibitor) and cimetidine 800 mg BID for 5 days (considered a weak CYP3A4 inhibitor) did not cause any changes in colchicine systemic levels, fluconazole 200 mg QD for 4 days with a 400 mg loading dose (considered a moderate CYP3A4 inhibitor) increased colchicine AUC by 40%. As voriconazole, cimetidine, and fluconazole are known as CYP3A4 inhibitors that do not inhibit P-gp, these studies show that CYP3A4 inhibition by itself may not lead to clinically significant increases in colchicine systemic levels in humans, and P-gp inhibition in addition to CYP3A4 inhibition may be necessary for clinically meaningful interactions of colchicine. However, based on published case reports that indicate the presence of colchicine toxicity when colchicine is co-administered with strong to moderate CYP3A4 inhibitors such as clarithromycin, erythromycin, grapefruit juice, etc., as well as the 40% increase in systemic levels of colchicines observed with concomitantly administered fluconazole (a moderate CYP3A4 inhibitor that is not known to inhibit P-gp) in a drug-drug interaction study, the drug-drug interaction potential of colchicine with strong or moderate CYP3A4 inhibitors that do not inhibit P-gp cannot be ruled out completely.
Co-administration of MITIGARE® with propafenone (a P-gp inhibitor) at 225 mg BID for 5 days, in a pharmacokinetic study in healthy volunteers, did not cause any changes in systemic levels of colchicine. This indicates that propafenone can be administered with MITIGARE® without any dose adjustment.
However, these results should not be extrapolated to other P-gp inhibitors as colchicine is known to be a substrate for P-gp and case reports of colchicine toxicity associated with the co-administration of Pgp inhibitors such as cyclosporine have been published.
