Yedidia Bentur

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. Colchicines 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.

Tissue plasminogen activator for the treatment of thromboembolism in infants and children

We report our experience with the use of tissue plasminogen activator to treat 12 infants and children with various thromboembolic states after conventional thrombolytic agents had failed. The dosage range was between 0.1 to 0.5 mg/kg per hour. Complete clot dissolution occurred in seven cases after 2 hours to 3 days of therapy. Partial clot dissolution and clinical improvement were noted in another four patients. Bleeding complications were noted in 6 of the 12 patients and included bruising, oozing from various venipuncture sites, and bleeding; these complications were controlled by clinically available means. In all cases with bleeding the dose rate was in the higher range (0.46 to 0.50 mg/kg per hour). In one patient, restlessness, agitation, and screaming were noted during administration of tissue plasminogen activator and when it was reinstituted. We conclude that tissue plasminogen activator is effective in inducing clot lysis in children. Because the effective dose appears to overlap with those causing bleeding, we recommend that a dose of 0.1 mg/kg per hour be started and increased gradually if clot dissolution does not occur, with close monitoring for bleeding.

Lessepsian migration and tetrodotoxin poisoning due to Lagocephalus sceleratus in the eastern Mediterranean

BACKGROUND The Suez Canal permits migration of fish from the Indo-Pacific Ocean to the Mediterranean Sea. This phenomenon (Lessepsian migration) has enabled poisonous fish species to colonize the Mediterranean Sea. OBJECTIVE To report clinical tetrodotoxin poisoning after consumption of the Lessepsian immigrant fish Lagocephalus sceleratus caught on the Israeli coast of the eastern Mediterranean. CASE SERIES Thirteen patients aged 26-70years were admitted after consuming L. sceleratus. Signs of toxicity appeared within 1h. The main manifestations included vomiting, diarrhea, headache, paraesthesias, slurred speech, muscle weakness, dyspnea, hypertension, tachycardia, respiratory arrest, seizures and coma. Treatment was supportive, including mechanical ventilation (two patients). Patients recovered within 4days. All fish were identified as L. sceleratus, a species known to contain tetrodotoxin. DISCUSSION The diagnosis of tetrodotoxin poisoning was suggested by typical clinical manifestations together with temporal proximity to consumption of tetrodotoxin-containing fish. To the best of our knowledge, this is the first case series of tetrodotoxin poisoning reported from the eastern Mediterranean and due to L. sceleratus. Man made disruption of the ecological balance has resulted in the spread of tetrodotoxin-containing fish from the Indo-Pacific region to the Mediterranean Sea. Increased awareness is required to identify tetrodotoxin poisoning in an atypical fauna.

The acute effects of water-pipe smoking on the cardiorespiratory system.

OBJECTIVE There are limited data on the acute effects of water-pipe tobacco smoking, commonly known as water-pipe smoking (WPS), on cardiopulmonary parameters. This study evaluated the acute effects of a single 30-min session of WPS on carboxyhemoglobin (COHb) levels, pulmonary function test results, vital signs, fractional exhaled nitric oxide (Feno) levels, and exhaled breath condensate (EBC) cytokine levels in volunteers in a domestic, open-air, group smoking setting. METHODS This prospective study evaluated the above-noted outcome parameters before and after 30 min of WPS. The primary outcome parameter was the change in COHb levels. RESULTS Forty-five volunteers (30 men, 15 women), aged 32.35 ± 15.33 years, were recruited. After one session of WPS, the COHb levels rose significantly, from 1.47% ± 0.57% (median 1.4) to 9.47% ± 5.52% (median 7.4), P < .001. Systolic and diastolic BP levels significantly increased after smoking (systolic, 119.52 ± 12.07 mm Hg vs 131.98 ± 17.8 mm Hg; diastolic, 74.84 ± 7.89 mm Hg vs 82.98 ± 12.52 mm Hg, respectively; P < .001). Heart rates increased from 80.39 ± 9.92 beats/min to 95.59 ± 17.41 beats/min, P < .001; and respiratory rates increased from 14.36 ± 1.63 breaths/min to 16.68 ± 2.24 breaths/min, P < .001. There were decreases in forced expiratory flow between 25% and 75% of FVC, peak expiratory flow rate, Feno levels, percentage of eosinophils in peripheral blood, and 8-isoprostane levels in EBC. CONCLUSIONS This study shows that one session of WPS causes acute biologic changes that might result in marked health problems. It adds to the limited evidence that WPS is harmful and supports interventions to control the continuing global spread of WPS, especially among youth. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01157832; URL: www.clinicaltrials.gov.

“Doctor, will that x-ray harm my unborn child?”

Abstract: Exposure to ionizing radiation can be a source of anxiety for many pregnant women and their health care providers. An awareness of the radiation doses delivered by different techniques and the acceptable exposure thresholds can help both patients and practitioners. We describe exposure to radiodiagnostic procedures during pregnancy and suggest an approach to assess the potential risk.

Hyperbaric oxygen therapy for cutaneous/soft-tissue zygomycosis complicating diabetes mellitus.

A 24-year-old female diabetic patient was hospitalized because of ketoacidosis and a necrotic wound on the hand. Debridement and antibiotic therapy failed to halt the process. After demonstration of Mucor in cultures from the wound, the patient underwent extensive surgery and amphotericin B was administered. When the necrotic process continued despite these measures, adjunctive hyperbaric oxygen (100% O2 at 2.5 ATA for 90 minutes) was administered daily for a total of 21 treatment sessions. She gradually improved, and at 2 months follow-up most of the wound had healed. Although the mortality rate of cutaneous/soft-tissue zygomycosis is markedly lower than that of the rhinocerebral form, morbidity is still considerably high. Successful use of hyperbaric oxygen has been reported in rhinocerebral zygomycosis, and it may have been of benefit in this high-risk patient by preventing local and systemic spreading of the fungus. This report is the first case of the use of hyperbaric oxygen for cutaneous/soft-tissue zygomycosis. It is suggested that hyperbaric oxygen be considered for this indication in diabetic patients as an adjunct to surgery and amphotericin B.

Deferoxamine (desferrioxamine). New toxicities for an old drug.

SummaryIron is an esssential element for body homoeostasis, but there is no effective mechanism for elimination of an excess of this mineral. Deferoxamine (desferrioxamine) is currently the treatment of choice for iron overload states from both acute iron intoxication and transfusion-dependent anaemias. The pharmacokinetics of deferoxamine are confounded both by its ability to chelate endogenous and exogenous iron and by the laboratory techniques used for its determination. Its iron-complex (ferrioxamine) has different pharmacokinetic properties. Because of its effectiveness, the use of deferoxamine is becoming more common, involving long term and high dose regimens. As a result of this, more and more toxicities that were not known in the past have been described and characterised. The most serious of these include hypotension, renal insufficiency, neurotoxicity, growth retardation and opportunistic infections; some of these side effects may be attributed to or aggravated by ferrioxamine. The pharmacological and toxicological literature on deferoxamine, and possible mechanisms for its toxicity, are reviewed and discussed.

Busulfan Use in Hematopoietic Stem Cell Transplantation: Pharmacology, Dose Adjustment, Safety and Efficacy in Adults and Children

Busulphan (1, 4-bis [methanesulfonyl-y] butane) is a bi-functional alkylating agent that, in combination with cyclophosphamide, has been commonly used in conditioning regimens before hematological stem cell transplantation (HSCT) for nearly 20 years. Busulfan has a very narrow therapeutic index, and acute toxicity may be related to absorption and disposition of the drug and metabolites. Precise delivery of the oral formulation is compromised by erratic gastrointestinal absorption, particularly in infants and small children. An intravenous busulfan formula was approved nearly 40 years after the approval of the oral formulation. Busulfan levels expressed as the area under the concentration-time curve (AUC) higher than 1500 microM* minute were reported to increase the risk of developing veno-occlusive disease (VOD), while low levels may result in engraftment failure or disease relapse. VOD occurs in 11-40% of patients undergoing HSCT and is associated with death in 3.3% of patients. Measurement of individual plasma busulfan levels during oral or intravenous dosing to obtain an AUC is likely to provide the necessary elements to monitor the drug disposition, ensuring efficacy and preventing toxicity of patients undergoing HSCT. It is also important to consider the busulfan drug-drug interactions and adverse drug reactions that can develop during the therapeutic process. Busulfan therapeutic drug monitoring and dose-adjustment should be performed in specialized laboratories staffed by well-trained personnel.

Laboratory and Clinical Acute Effects of Active and Passive Indoor Group Water-Pipe (Narghile) Smoking

BACKGROUND Indoor group water-pipe tobacco smoking, commonly referred to as water-pipe smoking (WPS), especially in coffee shops, has gained worldwide popularity. We performed a comprehensive laboratory and clinical evaluation of the acute effects of active and passive indoor group WPS. METHODS This comparative study evaluated pre- and post-30-min active and passive indoor group WPS. The outcome parameters were carboxyhemoglobin (COHb), nicotine, and cotinine levels; CBC count; and cardiorespiratory parameters. Exhaled breath condensate (EBC) cytokines and endothelial function (using the EndoPat device [Itamar Medical Ltd]) were measured only in active smokers. Statistical methods used were Student t test, Wilcoxon signed rank test, Fisher exact test, analysis of variance, and Newman-Keuls post hoc test where relevant. RESULTS Sixty-two volunteers aged 24.9±6.2 years were included; 47 were active smokers, and 15 were passive smokers. COHb level increased postactive WPS (active smokers, 2.0%±2.9% vs 17.6%±8.8%; P<.00001); six subjects (12.7%) had a >25% increase, and two subjects (4.2%) had a >40% increase. Plasma nicotine level increased postactive WPS (active smokers, 1.2±4.3 ng/mL vs 18.8±13.9 ng/mL; P<.0001); plasma cotinine and urinary nicotine and cotinine levels also increased significantly. EBC IL-4, IL-5, IL-10, IL-17, and γ-interferon decreased significantly with postactive smoking; endothelial function did not change. WPS was associated with adverse cardiorespiratory changes. In passive smokers, COHb level increased (0.8%±0.25% vs 1.2%±0.8%, respectively, P=.003) as did respiratory rate. CONCLUSIONS One session of active indoor group WPS resulted in significant increases in COHb and serum nicotine levels (eightfold and 18-fold, respectively) and was associated with adverse cardiorespiratory health effects. The minor effects found in passive smokers suggest that they too may be affected adversely by exposure to WPS. The results call for action to limit the continuing global spread of WPS in coffee shops. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT1237548; URL: www.clinicaltrials.gov.

SEVERE PULMONARY DISEASE IN ASSOCIATION WITH CROHN’S DISEASE IN A 13-YEAR-OLD GIRL

Pulmonary manifestations of Crohns disease are infrequent in adults and even less common in children. Our literature search found only a few cases of Crohns disease causing pulmonary manifestations in children. We report on the case of a 13‐year‐old girl in whom severe pulmonary disease was found four years after the onset of Crohns disease. Open lung biopsy uncovered bronchiolitis obliterans and granulomatous lung disease. Aggressive treatment has yielded gradual improvement. This case emphasizes the importance of recognizing the association, the differential diagnosis, and treatment implications. Pediatr Pulmonol. 2000; 29:151–154.