J Emerg Med. 2002 May;22(4):385-7.
Deaths associated with inappropriate intravenous colchicine administration.

Bonnel RA, Villalba ML, Karwoski CB, Beitz J.

Office of Drug Safety, Center for Drug Evaluation and Research, US Food and Drug Administration, Rockville, Maryland 20857, USA.

Intravenous (IV) colchicine is occasionally prescribed for the treatment of acute gouty arthritis. The Food and Drug Administration (FDA) recently received a report of death in a patient that was associated with inappropriate IV dosing of colchicine. This report prompted further investigation of other deaths associated with IV colchicine use in the FDA Adverse Event Reporting System (AERS) and the medical literature. A total of 20 deaths were identified. Eight patients were females, 11 were males, and the gender was unknown in 1. In all cases, the recommended maximum cumulative dose of 2 to 4 mg during a course of therapy was exceeded. Dose reductions are recommended in patients with renal or hepatic disease and in the elderly. All reported adverse events were associated with colchicine toxicity, including thrombocytopenia, leukopenia, pancytopenia, agranulocytosis, aplastic anemia, acute renal failure, and disseminated intravascular coagulopathy. Death occurred within 1 to 40 days after drug administration. Therapeutic guidelines exist for use of IV colchicine and these guidelines should be followed to prevent serious toxicities and death.


Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12113850&dopt=Abstract colchicine



J Cell Sci. 2002 Aug 1;115(Pt 15):3093-103.
MEK/ERK pathway mediates cell-shape-dependent plasminogen activator inhibitor type 1 gene expression upon drug-induced disruption of the microfilament and microtubule networks.

Samarakoon R, Higgins PJ.

Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York 12208, USA.

Changes in cellular morphology induced as a consequence of direct perturbation of cytoskeletal structure with network-specific targeting agents (i.e. microfilament- or microtubule-disrupting drugs) results in the stimulated expression of a specific subset of genes. Transcription of c-fos, collagenase, transforming growth factor-beta, actin, urokinase plasminogen activator and its type-1 inhibitor (PAI-1) appears to be particularly responsive to shape-activated signaling pathways. Cytochalasin D (CD) or colchicine treatment of contact-inhibited and serum-deprived vascular smooth muscle (R22) cells was used, therefore, as a model system to evaluate morphology-associated controls on PAI-1 gene regulation in the absence of added growth factors. PAI-1 transcript levels in quiescent R22 cells increased rapidly and in a CD-concentration-dependent fashion, with kinetics of expression paralleling the morphological changes. Colchicine concentrations that effectively disrupted microtubule structure and reduced the cellular 'footprint' area (to approximately that of CD treatment) also stimulated PAI-1 synthesis. Shape-related increases in PAI-1 mRNA synthesis were ablated by prior exposure to actinomycin D. Unlike the mechanism of induction in growth-factor-stimulated cells, CD- and colchicine-induced PAI-1 expression required on-going protein synthesis (i.e. it was a secondary response). Although PAI-1 is a TGF-beta-regulated gene and TGF-beta expression is also shape dependent, an autocrine TGF-beta loop was not a factor in CD-initiated PAI-1 transcription. Since CD exposure resulted in actin microfilament disruption and subsequent morphological changes, with uncertain effects on interactions between signaling intermediates or 'scaffold' structures, a pharmacological approach was selected to probe the pathways involved. Signaling events leading to PAI-1 induction were compared with colchicine-treated cells. CD- as well as colchicine-stimulated PAI-1 expression was effectively and dose dependently attenuated by the MEK inhibitor PD98059 (in the 10 to 25 microM concentration range), consistent with the known MAP kinase dependency of PAI-1 synthesis in growth-factor-stimulated cells. Reduced PAI-1 mRNA levels upon exposure to genistein prior to CD addition correlated with inhibition of ERK1/2 activity, implicating a tyrosine kinase in shape-dependent MEK activation. Src-family kinases, moreover, appeared to be specific upstream elements in the CD- and colchicine-dependent pathways of PAI-1 transcription since both agents effectively activated pp60(c-src) kinase activity in quiescent R22 cells. The restrictive (src-family) kinase inhibitor PP1 completely inhibited induced, as well as basal, ERK activity in a coupled immunoprecipitation myelin-basic-protein-phosphorylation assay and ablated shape-initiated PAI-1 mRNA expression. These data suggest that PP1-sensitive tyrosine kinases are upstream intermediates in cell-shape-associated signaling pathways resulting in ERK1/2 activation and subsequent PAI-1 transcription. In contrast to the rapid and transient kinetics of ERK activity typical of serum-stimulated cells, the ERK1/2 response to CD and colchicine is both delayed and relatively sustained. Collectively, these data support a model in which MEK is a focal point for the convergence of shape-initiated signaling events leading to induced PAI-1 transcription.


Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12118065&dopt=Abstract colchicine



Transpl Int. 2002 Jul;15(7):374-6. Epub 2002 Jun 20.
Colchicine myoneuropathy in a renal transplant patient.

Dupont P, Hunt I, Goldberg L, Warrens A.

Department of Renal Medicine, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.

Colchicine is widely employed for the treatment of gout in renal transplant patients where NSAIDs are contra-indicated and allopurinol prophylaxis is often avoided due to concomitant azathioprine immunosuppression. We report here a case of colchicine-induced myoneuropathy in a renal transplant recipient. Our patient had myalgia, muscle weakness, elevated creatine kinase levels, myopathic changes on electromyography and peripheral neuropathy. Withdrawal of colchicine resulted in recovery within 4 weeks. Renal transplant recipients are likely to be at greater risk of colchicine-induced myoneuropathy due to the unique concurrence of risk factors predisposing to toxicity in such patients. These risk factors include the high incidence of gout in this population, widespread use of colchicine as first-line therapy, impaired renal function and concomitant cyclosporin treatment. The diagnosis should be considered in any renal transplant recipient receiving the drug who develops myopathy. Prompt withdrawal of colchicine therapy should result in rapid clinical and biochemical improvement.


Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12122515&dopt=Abstract colchicine



Toxicology. 2002 Aug 1;177(1):105-17.
Anti-/pro-oxidant effects of phenolic compounds in cells: are colchicine metabolites chain-breaking antioxidants?

Modriansky M, Tyurina YY, Tyurin VA, Matsura T, Shvedova AA, Yalowich JC, Kagan VE.

Department of Environmental and Occupational Health, University of Pittsburgh, FORBL Room 234, 3343 Forbes Avenue, Pittsburgh, PA 15260, USA. oregounw.upol.cz

Effective scavenging of reactive radicals and low reactivity of generated secondary antioxidant radicals towards vital intracellular components are two critical requirements for a chain-breaking antioxidant. Tubulin-binding properties aside, colchicine metabolites remain largely untested for other possible biological activities, including antioxidant activity. Mourelle et al. [Life Sci. 45 (1989) 891] proposed that colchiceine (EIN) acts as an antioxidant and protective agent against lipid peroxidation in a rat model of liver injury. Since EIN as well as two other colchicine metabolites, 2-demethylcolchicine (2DM) and 3-demethylcolchicine (3DM), possess a hydroxy-group on their carbon ring that could participate in radical scavenging, we tested whether they can act as chain-breaking antioxidants. Using our fluorescence-HPLC assay with metabolically incorporated oxidation-sensitive cis-parinaric acid (PnA) we studied the effects of colchicine metabolites on peroxidation of different classes of membrane phospholipids in HL-60 cells. None of the colchicine metabolites in concentrations ranging from 10(-6) to 10(-4) M was able to protect phospholipids against peroxidation induced by either azo-initiators of peroxyl radicals or via myeloperoxidase (MPO)-catalyzed reactions in the presence of hydrogen peroxide. However, the metabolites did exhibit dose-dependent depletion of glutathione, resembling the behavior of etoposide, a hindered phenol with antioxidant properties against lipid peroxidation. Electron spin resonance (ESR) experiments demonstrated that in a catalytic system containing horseradish peroxidase (HRP)/H(2)O(2), colchicine metabolites undergo one-electron oxidation to form phenoxyl radicals that, in turn, cause ESR-detectable ascorbate radicals by oxidation of ascorbate. Phenoxyl radicals of colchicine metabolites formed through MPO-catalyzed H(2)O(2)-dependent reactions in HL-60 cells and via HRP/H(2)O(2) in model systems can also oxidize GSH. Thus, colchicine metabolites possess the prerequisites of many antioxidants, i.e. a nucleophilic hydroxy-group on a carbon ring and the ability to scavenge reactive radicals and form a secondary radical. However, the latter retain high reactivity towards critical biomolecules in cells such as lipids, thiols, ascorbate, thereby, rendering colchicine metabolites effective radical scavengers but not effective chain-breaking antioxidants.


Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12126799&dopt=Abstract colchicine