Haematological toxicity of colchicine

Colchicine: the good, the bad, the ugly and how to minimize the risks

Colchicine has an important role in managing various conditions, including gout, familial Mediterranean fever, amyloidosis, Behçet's syndrome, recurrent pericarditis and calcium pyrophosphate deposition disease. The adverse effect profile of colchicine is well understood. However, due to its narrow therapeutic index, colchicine has been associated with overdose and fatalities. When ingested in toxic amounts, the mainstay of management is supportive care. Strategies to minimize the risk of colchicine poisoning can focus on three broad causes: unauthorized access, intentional overdose and inappropriate dosing. Culturally safe and appropriate education about storage and appropriate use of colchicine is essential to minimize the risk of overdose.

Effect of an Accidental Colchicine Overdose in a COVID-19 Inpatient With Bilateral Pneumonia and Pericardial Effusion

A 32-year-old patient with COVID-19 pneumonia and pericardial effusion mistakenly took 15 mg of colchicine over 10 hours. He developed diarrhea that resolved two days after colchicine was stopped. Remarkably, this single overdose of colchicine, without any additional therapy, resulted in the complete recovery of bilateral pneumonia and pericardial effusion, and the patient was discharged on the hospital day 9th. This case demonstrates the possibility that high colchicine doses may have a major role and a dramatic effect in the treatment of COVID-19 patients.

Clinical outcomes after colchicine overdose: A case report

RATIONALE

Colchicine can inhibit cell division and intracellular transport in affected organs by fixing intracellular tubulin and preventing its polymerization into microtubules. A lethal dose of colchicine is considered to be 0.8 mg/kg. The wide distribution of colchicine through 70% of the body following an overdose makes it difficult to eliminate.

PATIENT CONCERNS

A 56-year-old man with a clear history of colchicine overdose was admitted to our hospital nearly 40 hours after taking 12 mg (0.17 mg/kg) of colchicine. He had a history of gout and chronic kidney disease. As the disease progressed, he showed most of the clinical manifestations and pathological features of colchicine overdose.

DIAGNOSES AND INTERVENTIONS

Colchicine overdose was clear, with symptoms of multiple organ failure including primary gastrointestinal failure, bone marrow hematopoietic inhibition, rhabdomyolysis, cardiac damage, hepatocyte damage. The patient developed secondary septic shock, renal failure, circulatory failure, and respiratory failure. We performed continuous renal replacement therapy and gastric lavage, and administered norepinephrine, frozen plasma, proton-pump inhibitors, adenosylmethionine, antibiotics, granulocyte colony stimulating factor, and total parenteral nutrition.

OUTCOMES

The patient rapidly developed complete hematopoietic function inhibition, gastrointestinal failure, and cardiac damage 32 hours after admission. Sustained severe infection and circulatory instability caused a progressive deterioration of respiratory function. Tracheal intubation was performed but the patient continued to deteriorate, and death occurred approximately 132 hours after admission.

LESSONS

Excessive colchicine levels cause continuous organ damage due to extensive tissue distribution, eventually leading to multiple organ failure. Colchicine metabolism is delayed in patients with liver or kidney dysfunction, and even a low dose of colchicine may result in poisoning in these individuals. Early diagnosis and reduction of colchicine levels is critical to improve prognosis, and colchicine poisoning should be considered in patients with poor liver or kidney function even when the ingested dose is low.

Computational models for the prediction of adverse cardiovascular drug reactions

Background

Predicting adverse drug reactions (ADRs) has become very important owing to the huge global health burden and failure of drugs. This indicates a need for prior prediction of probable ADRs in preclinical stages which can improve drug failures and reduce the time and cost of development thus providing efficient and safer therapeutic options for patients. Though several approaches have been put forward for in silico ADR prediction, there is still room for improvement.

Methods

In the present work, we have used machine learning based approach for cardiovascular (CV) ADRs prediction by integrating different features of drugs, biological (drug transporters, targets and enzymes), chemical (substructure fingerprints) and phenotypic (therapeutic indications and other identified ADRs), and their two and three level combinations. To recognize quality and important features, we used minimum redundancy maximum relevance approach while synthetic minority over-sampling technique balancing method was used to introduce a balance in the training sets.

Results

This is a rigorous and comprehensive study which involved the generation of a total of 504 computational models for 36 CV ADRs using two state-of-the-art machine-learning algorithms: random forest and sequential minimization optimization. All the models had an accuracy of around 90% and the biological and chemical features models were more informative as compared to the models generated using chemical features.

Conclusions

The results obtained demonstrated that the predictive models generated in the present study were highly accurate, and the phenotypic information of the drugs played the most important role in drug ADRs prediction. Furthermore, the results also showed that using the proposed method, different drugs properties can be combined to build computational predictive models which can effectively predict potential ADRs during early stages of drug development.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1918-z) contains supplementary material, which is available to authorized users.

Phospholipidic Colchicinoids as Promising Prodrugs Incorporated into Enzyme-Responsive Liposomes: Chemical, Biophysical, and Enzymological Aspects

Enzyme-responsive liposomes release their cargo in response to pathologically increased levels of enzymes at the target site. We report herein an assembly of phospholipase A2-responsive liposomes based on colchicinoid lipid prodrugs incorporated into lipid bilayer of the nanosized vesicles. The liposomes were constructed to addresses two important issues: (i) the lipid prodrugs were designed to fit the structure of the enzyme binding site; and (ii) the concept of lateral pressure profile was used to design lipid prodrugs that introduce almost no distortions into the lipid bilayer packing, thus ensuring that corresponding liposomes are stable. The colchicinoid agents exhibit antiproliferative activity in subnanomolar range of concentrations.

A critically ill patient after a colchicine overdose below the lethal dose: a case report

Background

Although 0.8 mg/kg is considered a lethal dose of colchicine, fatal cases of patients who followed a critical disease course after an intake below this lethal dose have been reported.

Case presentation

An 18-year-old Japanese woman who had taken an overdose of prescription colchicine (15 mg; 0.2 mg/kg) was brought to our emergency out-patient department. Although her colchicine intake was below 0.8 mg/kg (considered the lethal dose), she reached a critical state and underwent three phases characterizing colchicine poisoning (gastrointestinal symptoms, multiple organ failure, and recovery). Her condition was critical, with a Sequential Organ Failure Assessment score of a maximum of 14.

Conclusions

Patients might reach a critical stage after colchicine ingestion at a non-lethal dose. Thus, it might be necessary to review which dose of colchicine should be considered lethal.

Bronchiolitis Obliterans Organising Pneumonia in a Case of Colchicine Overdose

Colchicine is a commonly prescribed medication. Overdose of colchicine is relatively uncommon but can be fatal. We report a 36-year-old female who survived from severe colchicine poisoning and was subsequently complicated with bronchiolitis obliterans with organizing pneumonia. The patient required a long period of mechanical ventilation but eventually recovered on supportive care.

Electrophilicities and Protein Covalent Binding of Demethylation Metabolites of Colchicine

Colchicine, an alkaloid existing in plants of Liliaceous colchicum, has been widely used in the treatment of gout and familial Mediterranean fever. The administration of colchicine was found to cause liver injury in humans. The mechanisms of colchicine-induced liver toxicity remain unknown. The objectives of this study were to determine the electrophilicities of demethylation metabolites of colchicine and investigate the protein adductions derived from the reactive metabolites of colchicine. Four demethylated colchicine (1-, 2-, 3-, and 10-DMCs), namely, M1-M4, were detected in colchicine-fortified microsomal incubations. Four N-acetyl cysteine (NAC) conjugates (M5-M8) derived from colchicine were detected in the microsomes in the presence of NAC. M5 and M6 were derived from 10-DMC. M7 resulted from the reaction of 2-DMC or 3-DMC with NAC, and M8 originated from 10-DMC. Microsomal protein covalent binding was observed after exposure to colchicine. Two cysteine adducts (CA-1 and CA-2) derived from 10-DMC were found in proteolytically digested microsomal protein samples after incubation with colchicine. The findings allow us to define the chemical property of demethylation metabolites of colchicine and the interaction between protein and the reactive metabolites of colchicine generated in situ.

An Insidious Danger in Children With Familial Mediterranean Fever: Colchicine Intoxication

Colchicine is an anti-inflammatory drug, which has been used for the treatment of familial Mediterranean fever for several decades with narrow therapeutic-toxicity window. Colchicine poisoning is rare but frequently a life-threatening emergency condition in pediatric practice. It may occur by excessive ingestion of colchicine tablets accidentally or intentionally. Herein, we report a suicide attempt with colchicine in a 12-year-old girl who had been followed up with the diagnosis of familial Mediterranean fever. She was admitted to our emergency department with gastrointestinal complaints and subsequently died because of the rapidly deteriorating metabolic and hemodynamic conditions.

Colchicine as an anti-inflammatory and cardioprotective agent

INTRODUCTION

Colchicine has been successfully used for the treatment of neutrophilic disorders such as familial Mediterranean fever (FMF), Behçet disease (BD) and gout. There is a growing interest in its cardiovascular effects.

AREAS COVERED

A MEDLINE/PubMed search for English articles published from January 1972 to June 2015 was completed using the following terms: therapy, pharmacokinetics, efficiency, side effects, toxicity, heart, colchicine, inflammation, FMF, amyloidosis, BD, gout, cardiovascular disorders, pericarditis, arrhythmias, inflammation, neutrophils, platelets.

EXPERT OPINION

By targeting neutrophils, endothelial cells and platelets, inhibiting mitosis, vascular hyperplasia and fibrosis, colchicine improves outcomes of pericarditis, myocardial ischemia and coronary interventions. Studies in neutrophilic rheumatic diseases and cardiovascular disorders demonstrated that oral colchicine at doses of 0.5 - 2.5 mg/daily is useful for treating pericarditis, myocardial ischemia and coronary occlusion. In rheumatic and cardiovascular disorders, therapeutic doses of the drug reduce C-reactive protein to levels below 2 mg/L, prevent myocardial damage and preserve normal values of atrial and ventricular impulse generation. One of the drug's frequent side effects is diarrhea, which is treated by diet modification or temporary discontinuation of the therapy. Certain drugs (macrolides, statins), comorbidities and certain genetic factors increase risk of colchicine toxicity.

Colchicine overdose with coingestion of nonsteroidal antiinflammatory drugs

Colchicine has a low therapeutic index. Its toxic effects generally occur at doses ≥ 0.5 mg/kg. We present the case of a 39-year-old female with toxicity following ingestion of 0.28 mg/kg. The patient presented to the emergency department (ED) with severe nausea, vomiting, and abdominal pain following an intentional multidrug ingestion that included colchicine, indomethacin, and zopiclone. Despite toxicologic management and supportive care, admission to the intensive care unit was required for clinical deterioration and symptom management. Shock and multiorgan failure resulted, with death occurring 52 hours postingestion. Although the toxic effects of colchicine are well documented, mortality caused by low doses is relatively uncommon. Management of toxicity consists of early diagnosis, decontamination, and supportive measures. Toxicity may be enhanced by drug interactions inhibiting metabolic enzymes or poor excretion due to renal failure. In this case, the ingestion of a nonsteroidal antiinflammatory drug and the associated volume depletion from the gastrointestinal effects of colchicine may have contributed to renal dysfunction, exacerbating the toxicity of colchicine. This ingestion of a relatively small dose of colchicine led to severe toxicity. Treatment options for colchicine toxicity are limited.

A polymeric colchicinoid prodrug with reduced toxicity and improved efficacy for vascular disruption in cancer therapy

Colchicinoids are very potent tubulin-binding compounds, which interfere with microtubule formation, giving them strong cytotoxic properties, such as cell mitosis inhibition and induction of microcytoskeleton depolymerization. While this makes them promising vascular disrupting agents (VDAs) in cancer therapy, their dose-limiting toxicity has prevented any clinical application for this purpose. Therefore, colchicinoids are considered attractive lead molecules for the development of novel vascular disrupting nanomedicine. In a previous study, a polymeric colchicinoid prodrug that showed favorable hydrolysis characteristics at physiological conditions was developed. In the current study, this polymeric colchicinoid prodrug was evaluated in vitro and in vivo for its toxicity and vascular disrupting potential. Cell viability studies with human umbilical vein endothelial cells, as an in vitro measure for colchicine activity, reflected the degradation kinetics of the prodrug accordingly. Upon intravenous treatment, in vivo, of B16F10 melanoma-bearing mice with colchicine or with the polymeric colchicinoid prodrug, apparent vascular disruption and consequent tumor necrosis was observed for the prodrug but not for free colchicine at an equivalent dose. Moreover, a five-times-higher dose of the prodrug was well tolerated, indicating reduced toxicity. These findings demonstrate that the polymeric colchicinoid prodrug has a substantially improved efficacy/toxicity ratio compared with that of colchicine, making it a promising VDA for cancer therapy.

Colchicine poisoning: the dark side of an ancient drug

INTRODUCTION

Colchicine is used mainly for the treatment and prevention of gout and for familial Mediterranean fever (FMF). It has a narrow therapeutic index, with no clear-cut distinction between nontoxic, toxic, and lethal doses, causing substantial confusion among clinicians. Although colchicine poisoning is sometimes intentional, unintentional toxicity is common and often associated with a poor outcome.

METHODS

We performed a systematic review by searching OVID MEDLINE between 1966 and January 2010. The search strategy included "colchicine" and "poisoning" or "overdose" or "toxicity" or "intoxication."

TOXICOKINETICS

Colchicine is readily absorbed after oral administration, but undergoes extensive first-pass metabolism. It is widely distributed and binds to intracellular elements. Colchicine is primarily metabolized by the liver, undergoes significant enterohepatic re-circulation, and is also excreted by the kidneys. THERAPEUTIC AND TOXIC DOSES: The usual adult oral doses for FMF is 1.2-2.4 mg/day; in acute gout 1.2 mg/day and for gout prophylaxis 0.5-0.6 mg/day three to four times a week. High fatality rate was reported after acute ingestions exceeding 0.5 mg/kg. The lowest reported lethal doses of oral colchicine are 7-26 mg.

DRUG INTERACTIONS

CYP 3A4 and P-glycoprotein inhibitors, such as clarithromycin, erythromycin, ketoconazole, ciclosporin, and natural grapefruit juice can increase colchicine concentrations. Co-administration with statins may increase the risk of myopathy.

MECHANISMS OF TOXICITY

Colchicine's toxicity is an extension of its mechanism of action - binding to tubulin and disrupting the microtubular network. As a result, affected cells experience impaired protein assembly, decreased endocytosis and exocytosis, altered cell morphology, decreased cellular motility, arrest of mitosis, and interrupted cardiac myocyte conduction and contractility. The culmination of these mechanisms leads to multi-organ dysfunction and failure. REPRODUCTIVE TOXICOLOGY AND LACTATION: Colchicine was not shown to adversely affect reproductive potential in males or females. It crosses the placenta but there is no evidence of fetal toxicity. Colchicine is excreted into breast milk and considered compatible with lactation.

CLINICAL FEATURES

Colchicine poisoning presents in three sequential and usually overlapping phases: 1) 10-24 h after ingestion - gastrointestinal phase mimicking gastroenteritis may be absent after intravenous administration; 2) 24 h to 7 days after ingestion - multi-organ dysfunction. Death results from rapidly progressive multi-organ failure and sepsis. Delayed presentation, pre-existing renal or liver impairment are associated with poor prognosis. 3) Recovery typically occurs within a few weeks of ingestion, and is generally a complete recovery barring complications of the acute illness.

DIAGNOSIS

History of ingestion of tablets, parenteral administration, or consumption of colchicine-containing plants suggest the diagnosis. Colchicine poisoning should be suspected in patients with access to the drug and the typical toxidrome (gastroenteritis, hypotension, lactic acidosis, and prerenal azotemia).

MANAGEMENT

Timely gastrointestinal decontamination should be considered with activated charcoal, and very large, recent (<60 min) ingestions may warrant gastric lavage. Supportive treatments including administration of granulocyte colony-stimulating factor are the mainstay of treatment. Although a specific experimental treatment (Fab fragment antibodies) for colchicine poisoning has been used, it is not commercially available.

CONCLUSION

Although colchicine poisoning is relatively uncommon, it is imperative to recognize its features as it is associated with a high mortality rate when missed.

A roadmap for education to improve the quality of care in gout

PURPOSE OF REVIEW

To describe obstacles to optimum management of gout by primary care physicians and to propose educational interventions to improve care.

RECENT FINDINGS

In the past, gout education has been hampered by infrequency of continuing medical education courses, loss of excitement for a disease in which therapies have not changed (until recently), insufficient evidence-based medicine, and the lack of motivation by physicians to re-learn this disease once in active practice. We identify 10 common myths that impede appropriate treatment of gout, identify gaps in evidence-based medicine that perpetuate those myths, and propose opportunities to improve education on these myths. It is through better gout-centered education that quality of care in gout can be enhanced. Residency may be one of the key points of intervention. As more evidence-based medicine publications address the optimum management of gout, national re-education can occur. More outreach by community rheumatologists to primary care physicians through educational programs and improved referral letters can help re-educate practitioners. Lastly, an often overlooked engine to change physician practices is consumer education, but current patient education programs are lacking.

SUMMARY

Novel education interventions for physician trainees, primary care physicians, and patients are proposed to improve the care of patients with gout.