Brief report: treatment of severe colchicine overdose with colchicine-specific Fab fragments

Colchicine intoxication: a report of two suicide cases

Colchicine, an old and well-known drug, is an alkaloid extracted from Colchicum autumnale and related species. Colchicine inhibits the deposition of uric acid crystals and is an inhibitor of mitosis. Nausea, vomiting, abdominal pain, and diarrhea, with a massive loss of fluid and electrolytes are the first clinical symptoms of colchicine poisoning. Stomach lavage and rapid gastric decontamination with activated charcoal are crucial. An acute dose of about 0.8 mg/kg of colchicine is presumed to be fatal. We report the clinical outcomes of two different cases of colchicine intoxication for attempted suicide. The dose required for morbidity or mortality varies significantly. The dose of 1 mg/kg in the first case was directly related with mortality, while the dose of 0.2 mg/kg in the second was related with survival. The other difference between the patients was the time of arrival to hospital after ingestion. This period was 4 hours for case 1 and only 1, hour for case 2. The initiation of treatment later than 2 hours after ingestion of colchicine may significantly impair treatment because the absorption time for colchicine after oral administration is about 30-120 minutes. The rising lactate level and high anion gap metabolic acidosis in our patient (case 1) were attributed to lactic acidosis, so hemodialysis was performed, and the duration of hemodialysis was prolonged. Lactic acidosis in the first case was one of the reasons for mortality. The most important parameters which define the chance of survival are the dose of ingested drugs and the arrival time to hospital after ingestion. The patients must be monitored closely for lactic acidosis and the decision to start hemodialysis must be made promptly for patients who develop lactic acidosis.

Rugged and accurate quantitation of colchicine in human plasma to support colchicine poisoning monitoring by using turbulent-flow LC–MS/MS analysis

Background: Colchicine is a common drug used in inflammatory diseases. The narrow therapeutic index requires fast and reliable techniques for its quantitation. An online, automated sample preparation using TurboFlow™ technology combined with triple-stage quadrupole MS detection was applied to identify colchicine in human plasma and follow intoxications. Methodology: Plasma samples (200 µl) were mixed with deuterated colchicine and protein precipitation ZnSO4 solutions. After centrifugation, supernatants were extracted onto a Cyclone P TurboFlow column and eluted onto a narrowbore Hypersil™ GOLD column with a methanol/water gradient. Analytes were monitored in SRM mode (positive electrospray). Results: Total run time was 9.5 min. Calibration curves ranged from 0.342 to 17.1 ng/ml, with significant linearity (R2 >0.99). Inter- and intra-assay precisions were <16.8% and accuracy was 84.4–110%. Conclusion: This method is suitable for monitoring intoxication in patients undergoing chronic treatment and is routinely applied to toxicological samples.

Novel therapeutics for the treatment of familial Mediterranean fever: from colchicine to biologics

Familial Mediterranean fever (FMF), an inherited autosomal recessive disorder, is characterized by sporadic, paroxysmal attacks of fever and serosal inflammation, lasting 1-3 days. Patients may develop renal amyloidosis, arthritis, serositis, and skin and oral lesions. Diagnosis is based on clinical features, response to treatment with colchicine, and genetic analysis. Colchicine prevents attacks and renal amyloidosis, in addition to reversing proteinuria. Nonresponders may receive novel therapy, including interleukin (IL)-1 receptor antagonists and IL-1 decoy receptor. Recently, new options have been considered.

A specific antidote for dabigatran: functional and structural characterization

We present an antidote for dabigatran that effectively reverses its anticoagulative effect in human plasma in vitro and in rats in vivo. The antidote shares structural features with thrombin in the mode of binding but has no activity in coagulation tests.

Emergency abdominal surgery and colchicine overdose

We report a case of a patient with an unrecognized colchicine overdose presenting to the emergency department with acute abdominal symptoms rapidly progressing to multiorgan failure. The patient died 16 h after a negative explorative laparotomy despite intensive supportive care. The problem of colchicine overdose is briefly discussed. We suggest that surgeons should be aware of the clinical presentation of colchicine overdose as it can mimic acute abdominal diseases.

Predicting the clinical efficacy and potential adverse effects of a humanized anticocaine monoclonal antibody

The effects of a humanized monoclonal antibody (mAb) having high affinity and specificity for cocaine in animal models are reviewed. The mAb reduced the concentration of cocaine in the brain of mice after intravenous injection of cocaine. In addition, the mAb increased the concentration of cocaine required to reinstate cocaine self-administration. These effects may predict clinical efficacy of a passive immunotherapy for reducing the probability of cocaine-induced relapse. However, in the presence of the mAb, once cocaine self-administration was reinstated, the consumption rate of cocaine was increased. This effect is hypothesized to result from a pharmacokinetic/pharmacodynamic interaction. A humanized mAb should minimize adverse events related to the immunogenicity of the mAb protein, and the specificity for cocaine should avoid adverse events related to interactions with physiologically relevant endogenous proteins.

Colchicine in clinical medicine. A guide for internists

Colchicine (COL) has been used in medicine for a long time. It is well recognized as a valid therapy in acute flares of gouty arthritis, familial Mediterranean fever (FMF), Behçet's disease, and recurring pericarditis with effusion. It has also been used to treat many inflammatory disorders prone to fibrosis, mostly with disappointing therapeutic results. The pharmacotherapeutic mechanism of action of COL in diverse diseases is not fully understood, thought it is known that the drug accumulates preferentially in neutrophils, and this effect is useful in FMF. COL shows a large interindividual bioavailability. Furthermore, interactions with drugs interfering with CYP3A4 dependent enzymes and P-glycoprotein occur and are clinically important. The dosage of COL must be reduced in patients with relevant hepatic and/or renal dysfunction. However, when appropriately used and contraindications have been excluded, oral COL is a safe treatment.

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 Fatal Case of Autumn Crocus (Colchicum Autumnale) Poisoning in a Heifer: Confirmation by Mass-Spectrometric Colchicine Detection

A heifer developed severe signs of acute gastrointestinal irritation 48 hr after ingesting fresh leaves of Colchicum autumnale growing on a damp meadow. Confirmation of the suspected toxicosis was obtained by detecting colchicine in serum and urine using liquid chromatography coupled with tandem mass spectrometry using atmospheric pressure chemical ionization. Although the serum colchicine concentration had declined to an apparently nontoxic level of 2.4 ng/ml, a more prominent concentration (640 ng/ml) indicative of colchicine poisoning was detected in the urine. This finding is consistent with the known toxicokinetic properties of colchicine, whereby a large volume of distribution results in low circulating blood concentrations and prolonged urinary excretion.

Colchicine Overdose—The Need for a Specific Antidote

Purpose

To report the case of a colchicine overdose to highlight current limitations in the treatment of this toxicologic emergency.

Summary

A 23-year-old man was admitted to the intensive care unit (ICU) after attempting suicide via polypharmacy ingestion, which included 80 to 100 colchicine 0.6 mg tablets (approximately 0.9 mg/kg of body weight). He was taken to the emergency department where gastric decontamination was initiated. Because attempts to obtain a colchicine-specific antibody fragment (Fab) were unsuccessful, only supportive therapies were provided throughout his hospitalization. Over the course of several days, the patient experienced the 3 separate evolutionary phases of colchicine toxicity ultimately leading to multiple organ failure and hemodynamic collapse, and death.

Conclusion

Acute colchicine intoxication is a rare, but potentially life-threatening event. Although 1 case report demonstrated the successful use of a colchicine-specific Fab fragment in the management of acute colchicine overdose, there is presently no commercially-available antidote for colchicine toxicity. Prompt recognition of the overdose, aggressive gastrointestinal decontamination, and supportive therapies directed at the multi-organ failure remain the standard of care.

Colchicine revisited

Purified from a Mediterranean plant nearly two centuries ago, colchicine has been discovered to inhibit many steps in the inflammatory process. The drug has good oral bioavailability and some enterohepatic recirculation, requiring dose adjustments for kidney disease and avoidance in liver disease. Toxicities are primarily gastrointestinal, hepatic, and hematologic. Colchicine is approved by the U.S. Federal Drug Administration for the treatment and prophylaxis of gout flares but has also been tried with varying success in the treatment of familial Mediterranean fever, primary biliary cirrhosis, psoriasis, Behçet's disease, aphthous stomatitis, linear IgA dermatosis, relapsing polychondritis, Sweet's syndrome, scleroderma, amyloidosis, leukocytoclastic vasculitis, epidermolysis bullosa, and dermatomyositis.

Colchicine exposures: the Texas experience

OBJECTIVES

Colchicine is a relatively uncommon toxin, but is known to precipitate severe multiorgan failure in overdose. Little is known about exposure patterns and outcomes in cases of colchicine ingestion. Our goal was to add to toxicologic knowledge through a database review and descriptive study of colchicine exposures.

METHODS

Texas Poison Center Network Data was reviewed for the years 2000 to 2005, and all reports of colchicine exposures were reviewed.

RESULTS

A total of 79 cases were found in the time period studied. The most common exposure reasons were unintentional-therapeutic error (33%), unintentional-general (28%), and intentional-suspected suicide (18%). Medical outcomes included no effect (24%), minor effect (20%), moderate effect (15%), and major effect (3%). The most common clinical findings included vomiting (20%), diarrhea (17%), and abdominal pain (7%). The most commonly employed therapies were dilution (28%), single-dose activated charcoal (26%), cathartics (16%), and gastrointestinal lavage (15%).

CONCLUSION

The majority of cases of exposure produced no significant effects, and fatality was uncommon in this sample. Colchicine is a relatively uncommon toxin among therapeutic drugs, and though capable of it, is rarely responsible for significant morbidity or mortality. Meticulous exposure record keeping at poison centers is a key to the study of patterns of toxicity with uncommon toxins such as colchicine.

Clinical review: aggressive management and extracorporeal support for drug-induced cardiotoxicity

Poisoning may induce failure in multiple organs, leading to death. Supportive treatments and supplementation of failing organs are usually efficient. In contrast, the usefulness of cardiopulmonary bypass in drug-induced shock remains a matter of debate. The majority of deaths results from poisoning with membrane stabilising agents and calcium channel blockers. There is a need for more aggressive treatment in patients not responding to conventional treatments. The development of new antidotes is limited. In contrast, experimental studies support the hypothesis that cardiopulmonary bypass is life-saving. A review of the literature shows that cardiopulmonary bypass of the poisoned heart is feasible. The largest experience has resulted from the use of peripheral cardiopulmonary bypass. However, a literature review does not allow any conclusions regarding the efficiency and indications for this invasive method. Indeed, the majority of reports are single cases, with only one series of seven patients. Appealing results suggest that further studies are needed. Determination of prognostic factors predictive of refractoriness to conventional treatment for cardiotoxic poisonings is mandatory. These prognostic factors are specific for a toxicant or a class of toxicants. Knowledge of them will result in clarification of the indications for cardiopulmonary bypass in poisonings.

Adjuvant chemotherapy with 5-fluorouracil in a patient with colorectal cancer and Familial Mediterranean Fever

Colorectal cancer is a common malignancy often requiring adjuvant chemotherapy. Familial Mediterranean Fever is a chronic hereditary disease which is relatively prevalent in the Middle East and is associated with recurrent episodes of serosal, synovial or cutaneous inflammations. The aim of this paper was to describe a patient with Familial Mediterranean Fever who received fluorouracil-based adjuvant chemotherapy for colorectal cancer. A 56-year-old man with Familial Mediterranean Fever and amyloidosis was referred for evaluation and treatment following surgery for colorectal cancer. In light of his relatively young age, good general state of health and apparently well-controlled Familial Mediterranean Fever, he was treated with chemotherapy consisting of four cycles of 5-fluorouracil and leucovorin. The patient's clinical course during chemotherapy was unremarkable except for one minor attack of Familial Mediterranean Fever. The patient's follow-up was notable for periodic fluctuations in serum carcinoembryonic antigen levels, up to 4-fold of normal. The Familial Mediterranean Fever remained stable. Although our patient showed a good tolerability of treatment, the administration of chemotherapy to patients with Familial Mediterranean Fever raises several concerns. These include a potential deterioration in the Familial Mediterranean Fever status owing to chemotherapy-induced stress, the potential effect of Familial Mediterranean Fever or its treatment on the tolerability of chemotherapy and an overlapping toxicity of the drugs used to treat the two diseases. An increase in serum carcinoembryonic antigen in this setting may be related to the underlying pathophysiologic mechanism of Familial Mediterranean Fever but does not necessarily indicate disease recurrence. Clinicians should be aware of these issues considering the recent worldwide increase in colorectal cancer.

Colchicine use in children and adolescents with familial Mediterranean fever: literature review and consensus statement

The daily application of colchicine is the standard therapy for prophylaxis of attacks and amyloid deposition in familial Mediterranean fever. However, because of many issues (eg, dosage, time of introduction, etc), no standardized treatment recommendations have been established. In this work we review the available literature on colchicine use with respect to its indication, efficacy, mode of application, and safety in children and adolescents with familial Mediterranean fever. On the basis of this analysis, a consensus statement on the application of colchicine in children and adolescents with familial Mediterranean fever was developed by caregivers from Germany, Austria, and Turkey.

Colchicine today

Colchicine is used chiefly in the treatment of gout but is also valuable in other inflammatory diseases such as familial Mediterranean fever (FMF). Three proteins play pivotal roles in colchicine pharmacokinetics: the colchicine receptor, tubulin, which governs the plasma elimination half-life of the drug; intestinal and hepatic CYP3A4, which is key to the biotransformation of colchicine; and P-glycoprotein, a cell efflux pump that regulates the tissue distribution of colchicine, as well as its excretion via the biliary tract and kidneys. Pharmacokinetic studies have been performed using a radioimmunology assay to measure blood colchicine levels. Absorption after oral ingestion varies widely (from 24% to 88% of the dose), the volume of distribution is extremely large (7 l/kg), and binding to albumin is moderate. Colchicine is excreted chiefly through the liver and has an elimination half-life of 20-40 hours. With repeated doses of about 1mg/day, the steady-state is achieved within 8 days and concentrations range from 0.3 to 2.5 ng/ml. Studies of associations between pharmacokinetic parameters and pharmacodynamics show that effects are correlated, not to plasma levels, but to levels in leukocytes. Adverse events are not uncommon, most notably when colchicine is used in combination with drugs that interact with CYP3A4 and/or P-glycoprotein, thereby decreasing the renal and/or hepatic elimination of colchicine. Careful monitoring in this situation is effective in preventing the development of toxicity.

Fatal Interaction between Clarithromycin and Colchicine in Patients with Renal Insufficiency: A Retrospective Study

BACKGROUND

Clarithromycin is frequently used to treat community-acquired pneumonia in elderly persons. Like erythromycin, it may interact with other drugs by interfering with metabolism by cytochrome P450 enzymes and with the P-glycoprotein transporter system. Colchicine, used for treatment of acute gout and for prophylaxis, may cause bone marrow toxicity. It is metabolized by CYP3A4 and is transported by P-glycoprotein. Initial case reports suggested potentially fatal interactions between clarithromycin and colchicine.

METHODS

A retrospective study was conducted with 116 patients who were prescribed clarithromycin and colchicine during the same clinical admission. Case-control comparisons were made between patients who received concomitant therapy with the 2 drugs and patients who received sequential therapy. We assessed the clinical presentations and outcomes of the 2 patient groups and analyzed the risk factors associated with fatal outcomes.

RESULTS

Nine (10.2%) of the 88 patients who received the 2 drugs concomitantly died. Only 1 (3.6%) of the 28 patients who received the drugs sequentially died. Multivariate analysis of the 88 patients who received concomitant therapy showed that longer overlapped therapy (relative risk [RR], 2.16; 95% confidence interval [CI], 1.41-3.31; P< or =.01), the presence of baseline renal impairment (RR, 9.1; 95% CI, 1.75-47.06; P<.001), and the development of pancytopenia (RR, 23.4; 95% CI, 4.48-122.7; P<.001) were independently associated with death.

CONCLUSIONS

Clarithromycin increases the risk of fatal colchicine toxicity, especially for patients with renal insufficiency. Since there are other drugs for treatment of pneumonia and gout, these 2 drugs should not be coprescribed, because of the risk of fatality.

Colchicine-related death presenting as an unknown case of multiple organ failure

A 45-year-old man presented to the emergency department (ED) with acute renal and hepatic failure as well as hypotension and metabolic acidosis. Despite aggressive intensive care, he had continued hypotension, leukocytosis, fever, renal and hepatic failure, and lactic acidosis. On hospital day 3, pancytopenia was noted. Bone marrow biopsy showed marked aplasia without a specific etiology being elucidated. He received granulocyte colony-stimulating factor and antibiotics, but died on hospital day 12 after a cardiac arrest. The patient repeatedly denied intentional drug ingestion. Due to his clinical course, the poison center recommended obtaining a colchicine level. The plasma colchicine level, 72 h after admission, was 6.1 ng/mL (GC/MS). This level exceeds acute levels reported in some cases of prior fatalities. This case is novel in that the patient's multiple organ dysfunction remained unexplained for several days before occult colchicine toxicity was implicated as the probable cause by the colchicine level. Also, there was a paucity of gastrointestinal symptoms on presentation, the opposite of what is expected in colchicine toxicity.

Fab antibody fragments: some applications in clinical toxicology

This review provides current information on the use of antigen-binding fragments (Fab) from cleaved antibodies to treat poisoning with digoxin and other potent, low formula mass poisons, such as colchicine and tricyclic antidepressants. Anti-digoxin Fab fragments have been used successfully for many years in the management of severe poisoning with digoxin, digitoxin, and a range of other structurally related compounds, including cardiotoxins from Nerium and Thevetia sp. (oleander) and Bufo sp. (toads). However, their main use remains treating digoxin poisoning. Equimolar doses of anti-digoxin Fab fragments completely bind digoxin in vivo. The approximate dose of Fab fragments (mg) is 80 times the digoxin body burden (mg). If neither the dose ingested nor the plasma digoxin/digitoxin concentration is known, in an adult 380 mg of anti-digoxin Fab fragments should be given. The dose for elderly patients or those with renal impairment should be similar to that for those with normal renal function. Fab fragments have a plasma half-life of 12-20 hours, but this can be prolonged in patients with renal impairment. Analysis of serum ultrafiltrate using an immunoassay shown not to have matrix bias remains the most accurate approach to measuring free digoxin in the presence of anti-digoxin Fab fragments. The antibody fragments are given intravenously over 15-30 minutes after dilution to at least 250 mL with plasma protein solution, 0.9% (w/v) sodium chloride, or deionised water, except in infants where the volume infused can be reduced. Factors limiting the efficacy of Fab fragments are the dose, the duration of the infusion and any delay in administration. Guidelines for Fab fragment administration in children include (i) dilution to a final Fab concentration of 10 g/L in either 5% (w/v) dextrose or 0.9% (w/v) sodium chloride; (ii) infusion through a 0.22 microm filter; (iii) administration of the total dose over a minimum of 30 minutes; and (iv) avoiding coadministration of other drugs and/or electrolyte solutions. Fab fragments are generally well tolerated. Adverse effects attributable to Fab treatment include hypokalaemia and exacerbation of congestive cardiac failure; renal function could be impaired in some patients. Fab fragment preparations for treating acute colchicine and tricyclic antidepressant poisoning have been developed, but are not available commercially. Colchicine poisoning is rare in Western countries, and pharmacological management together with supportive care is usually effective even in severe tricyclic antidepressant overdosage. Attempts have been made to produce anti-paraquat antibodies capable of enhancing paraquat elimination from the lung, but thus far all such attempts have proved unsuccessful.

Accidental Intravenous Colchicine Poisoning

Colchicine is a commonly used drug for the treatment of gout and other indications. Toxicity from intentional oral overdoses of colchicine has been reported. Two cases are reported here in which colchicine was given by intravenous injection, and patients presented with multiorgan toxicity. The authors tested plasma and urine colchicine levels in these patients and found them significantly elevated. Testing of the vial from which the colchicine injections were given showed that the vial was mislabeled and contained 10-fold greater concentration of drug than the labeling indicated. These patients thus received a bolus dose of 20 mg of intravenous colchicine rather than the intended 2-mg dose. An intravenous dose of this magnitude has not previously been reported.

Toxic epidermal necrolysis-like reaction secondary to colchicine overdose

Colchicine is a microtubule-inhibiting drug used to treat gout, familial Mediterranean fever and many other skin diseases. Intoxication with colchicine affects multiple organs, often fatally. Cutaneous sequelae of colchicine toxicity are rare. We describe the clinical and histological features of a toxic epidermal necrolysis-like exanthem in a patient who lethally overdosed on colchicine.

Plant exposures: wilderness medicine

This article discusses poisonous plants, the symptoms that might arise if they are ingested, and the treatments that should be administered to patients.

Accidental Poisoning with Autumn Crocus

We describe a case of a 43-yr-old female with severe multiorgan injury after accidental poisoning with Colchicum autumnale, which was mistaken for wild garlic (Allium ursinum). Both plants grow on damp meadows and can be confused in the spring when both plants have leaves but no blossoms. The autumn crocus contains colchicine, which inhibits cellular division. Treatment consisted of supportive care, antibiotic therapy, and granulocyte-directed growth factor. The patient was discharged from the hospital after three weeks. Three years after recovery from the acute poisoning, the patient continued to complain of muscle weakness and intermittent episodes of hair loss.

Case report: fatal poisoning with Colchicum autumnale

INTRODUCTION

Colchicum autumnale, commonly known as the autumn crocus, contains alkaloid colchicine with antimitotic properties.

CASE REPORT

A 76-year-old man with a history of alcoholic liver disease and renal insufficiency, who mistakenly ingested Colchicum autumnale instead of wild garlic (Aliium ursinum), presented with nausea, vomiting and diarrhea 12 hours after ingestion. On admission the patient had laboratory signs of dehydration. On the second day the patient became somnolent and developed respiratory insufficiency. The echocardiogram showed heart dilatation with diffuse hypokinesia with positive troponin I. The respiratory insufficiency was further deteriorated by pneumonia, confirmed by chest X-ray and later on by autopsy. Laboratory tests also revealed rhabdomyolysis, coagulopathy and deterioration of renal function and hepatic function. The toxicological analysis disclosed colchicine in the patient's urine (6 microgram/l) and serum (9 microgram/l) on the second day. Therapy was supportive with hydration, vasopressors, mechanical ventilation and antibiotics. On the third day the patient died due to asystolic cardiac arrest.

DISCUSSION AND CONCLUSION

Colchicine poisoning should be considered in patients with gastroenterocolitis after a meal of wild plants. Management includes only intensive support therapy. A more severe clinical presentation should be expected in patients with pre-existing liver and renal diseases. The main reasons for death are cardiovascular collapse, respiratory failure and leukopenia with infection.

Clinical toxinology--where are we now?

Clinical toxinology encompasses a broad range of medical conditions resulting from envenomation by venomous terrestrial and marine organisms, and also poisoning from ingestion of animal and plant toxins. Toxin-related disease is an important cause of morbidity and mortality worldwide, particularly in the tropical and subtropical continents. Snake bite is the single most important toxin-related disease, causing substantial mortality in many parts of Africa, Asia, and the Americas. The most important snake families are Viperidae and Elapidae, causing a range of clinical effects including local necrosis, neurotoxicity, coagulopathy and hemorrhage, myotoxicity and renal toxicity. These effects vary according to geography and group of snake. Arachnid envenomation results mainly in morbidity, particularly scorpion stings which can cause severe systemic envenomation. Spider bite is far less of a problem, and the majority of medically important cases can be attributed to widow spiders (Latrodectus spp.) and recluse spiders (Loxosceles spp.). Marine-related envenomations are common, but severe effects are less so. Plant and mushroom poisoning occur in most parts of the world, but the types and methods of poisoning vary considerably between continents. Management of toxin-related disease is often difficult, and in many cases meticulous supportive care is all that is available. The mainstay of treatment is the use of antivenoms for many envenomations and poisoning, although these do not exist for all dangerous organisms. Unfortunately antivenoms are not an economically viable product, so development and manufacture of these agents have been limited. This is now further worsened by a current shortage of antivenom. There is a need for improvement in the preventionand management of toxin-related disease. This will require well-designed studies to define the extent of the problem, initiatives to improve the prevention and management of these conditions, and development of new, and continuation of current, antivenom supplies.

Acute plant poisoning and antitoxin antibodies

Plant poisoning is normally a problem of young children who unintentionally ingest small quantities of toxic plants with little resulting morbidity and few deaths. In some regions of the world, however, plant poisonings are important clinical problems causing much morbidity and mortality. While deaths do occur after unintentional poisoning with plants such as Atractylis gummifera (bird-lime or blue thistle) and Blighia sapida (ackee tree), the majority of deaths globally occur following intentional self-poisoning with plants such as Thevetia peruviana (yellow oleander) and Cerbera manghas (pink-eyed cerbera or sea mango). Antitoxins developed against colchicine and cardiac glycosides would be useful for plant poisonings--anti-digoxin Fab fragments have been shown to be highly effective in T. peruviana poisoning. Unfortunately, their great cost limits their use in the developing world where they would make a major difference in patient management. Therapy for some other plant poisonings might also benefit from the development of antitoxins. However, until issues of cost and supply are worked out, plant antitoxins are going to remain a dream in many of the areas where they are now urgently required.

Data collection in clinical toxicology: are there too many variables?

The evidence base of clinical toxicology suffers in comparison to other clinical disciplines. There is an excess of case reports and case series with little in the way of case control or cohort studies, and very few randomized controlled trials. While randomized controlled trials are rightly regarded as the gold standard for interventional studies, they have limitations that are particularly evident in the practice of clinical toxicology. Properly conducted observational studies using quantitative, epidemiological methods [nonrandomized trials, cohort studies (prospective and retrospective), case control methods] can provide answers that may be impossible to obtain from randomized controlled trials. Development of a strong evidence base is essential for progress in clinical toxicology. Whether that evidence base is derived from randomized controlled trials or observational studies, it is essential to collect data. Important observations can be made from basic clinical data and systematic collection of those data into some form of electronic database has siginificant advantages. A clinical database provides accurate information in the areas of clinical practice, quality assurance (audit), and research. In the area of research, an appropriately designed database can be both a source of hypotheses as well as a vehicle to test them. It can also serve as a repository of research data in subsequent randomized controlled trials.

Update on colchicine and its mechanism of action

Colchicine is a unique anti-inflammatory drug with respect to its limited clinical usefulness and its mode of action. Colchicine is mainly indicated for the treatment and prophylaxis of gout and familial Mediterranean fever. Its mode of action includes modulation of chemokine and prostanoid production and inhibition of neutrophil and endothelial cell adhesion molecules by which it interferes with the initiation and amplification of the joint inflammation. This paper discusses its adverse effects and indications.

Late diagnosis of severe colchicine intoxication

A 4-year-old Turkish girl was referred to our hospital with the findings of encephalopathy and pancytopenia. She had a history of severe abdominal cramps and gastrointestinal bleeding. A confused state, muscle pain and weakness, erythema-bullous and erythema-nodosum-like skin lesions, and alopecia were observed at her hospitalization. All of these symptoms resolved on follow-up. On laboratory investigation severe thrombocytopenia and leukopenia, mild anemia, a moderate increase in aspartate aminotransferase and alanine aminotransferase levels were detected. After reevaluating her medical history, it was learned that she had accidentally taken 1.3 to 1.5 mg/kg of colchicine 3 to 4 days before her first hospitalization. The possibility of misdiagnosis of colchicine intoxication should be borne in mind, and pediatricians must be aware of its toxic effects, especially in areas where patients with familial Mediterranean fever are present.

Enhanced cellular uptake and transport of polyclonal immunoglobulin G and fab after their cationization

Antibodies are poorly transported across cell membranes and biological barriers in vivo. Cationization of antibody molecules by the derivatization of surface carboxyl groups generating primary amino groups could represent a strategy for intracellular antibody delivery. Before cationization of polyclonal colchicine-specific IgG and Fab, using hexamethylenediamine the isoelectric point (pl) of native IgG and Fab (nIgG and nFab) was in the range of 5.9 9.0 and 8.7-9.3, respectively. The pI of cationized IgG and Fab (cIgG and cFab) were both higher at 8.7, 10.3 and 9.5 -11, respectively. The affinity and specificity of both IgG and Fab were not modified by cationization. When HL 60 cells were incubated with the native or cationized 125I-BSA. -IgG and -Fab, the maximal cellular uptake of clgG and cFab was 3.2 and 2.4 times higher than that of nIgG and nFab at an extracellular concentration of 500 ng/ml. Results also indicated that the uptake was dose- and temperature-dependent suggesting absorptive-mediated endocytosis of cationized antibodies by HL 60 cells. Confocal microscopy analysis indicated that the cationized antibodies were present in the plasma membranes and cytoplasm of HL 60 cells. Finally, a study with bovine arterial endothelial monolayer cells showed that the transport of cIgG and cFab through the monolayer cells was 3.3- and 4.3-fold higher for 125I-cIgG and 125I-cFab than those of the corresponding native forms.

Colchicine-induced bone marrow suppression: treatment with granulocyte colony-stimulating factor

Bone marrow aplasia is a frequent complication of colchicine poisoning. This typically occurs on day 3 to 5 postexposure, and the blood cell counts remain depressed for a week or more. Unfortunately, because patients suffering from colchicine toxicity develop multiple organ complications and sepsis, the morbidity and mortality associated with bone marrow depression is high. In this article, we present three cases of colchicine toxicity in which granulocyte colony-stimulating factor (G-CSF) was used to treat bone marrow depression. In all three cases, there was a dramatic increase in the white cell count and, to a lesser extent, the platelet count. In view of the critical nature of the bone marrow depression and multi-organ toxicity induced by colchicine, we believe that consideration of the use of G-CSF to shorten the duration of neutropenia is warranted.

Intradermal anti-loxosceles Fab fragments attenuate dermonecrotic arachnidism

OBJECTIVE

Bites from the brown recluse spider and other arachnids from the genus Loxosceles frequently induce necrotic skin lesions that can be recalcitrant to treatment and disfiguring. The authors used a rabbit model of dermonecrotic arachnidism to address the therapeutic efficacy of intradermal (id) polyclonal anti-Loxosceles Fab fragments (alphaLoxd Fab) raised against Loxosceles deserta spider venom.

METHODS

Fab fragments were prepared by papain digestion and affinity chromatography from the IgG fraction of L. deserta antivenom raised in rabbits. Eighteen inbred New Zealand white rabbits were assigned to six groups of three. The rabbits received L. deserta venom (3 microg, id) injections into each flank. Cohorts of rabbits received single id injections (at one venom site/rabbit) of 30 microg alphaLoxd Fab at different times (T = 0, 1, 2, 4, 8, and 12 hours) after venom injection. In each rabbit the opposite flank was left untreated. As an additional control, one group of rabbits (T = 0) received nonspecific Fab (30 microg, id) in the opposite flank. Dermal lesions were quantified as a function of time through the use of a series of digital photographs and imaging software. In addition, myeloperoxidase (MPO) activity, a measure ofneutrophil accumulation, was determined in lesion biopsies. Lesion areas and MPO activities were analyzed by repeated-measures analysis of variance (ANOVA).

RESULTS

Lesion areas and MPO activity were markedly reduced when alphaLoxd Fab was administered very early after venom injections. As the interval between venom inoculation and antivenom treatment increased, the therapeutic benefit of alphaLoxd Fab decreased. The final time tested that demonstrated therapeutic efficacy of alphaLoxd Fab was T = 4 hours. Lesion attenuation was no longer apparent when alphaLoxd Fab was given 8 hours post inoculation.

CONCLUSIONS

Intradermal administration of alphaLoxd Fab attenuates Loxosceles-induced dermonecrotic lesion formation when given up to 4 hours after venom inoculation in this rabbit model.