Toxicological risks on the human health of populations living around the Mediterranean Sea linked to the invasion of non-indigenous marine species from the Red Sea: A review

The Mediterranean region is, by far, a prime travel destination, having hosted more than 330 million tourists in 2016, mostly for seaside holidays. A greatly increased influx of thermophilic Red Sea species, introduced through the Suez Canal in a process referred to as Lessepsian invasion (in honor of Ferdinand de Lesseps who instigated the building of the Suez Canal), have raised awareness among scientists, medical personnel, and the public, of health risks caused by some venomous and poisonous marine species. The main species of concern are the poisonous Lagocephalus sceleratus, and the venomous Plotosus lineatus, Siganus luridus, Siganus rivulatus, Pterois miles, Synancea verrucosa, Rhopilema nomadica, Macrorhynchia philippina and Diadema setosum. Recognizing that the main factors that drive the introduction and dispersal of Red Sea biota in the Mediterranean, i.e., Suez Canal enlargements and warming seawater, are set to increase, and international tourist arrivals are forecasted to increase as well, to 500 million in 2030, an increase in intoxications and envenomations by alien marine species is to be expected and prepared for.

The role of chest and abdominal computed tomography in assessing the severity of acute corrosive ingestion

CONTEXT

Corrosive substance ingestion is a toxicological emergency with relatively high mortality requiring rational surgical decisions.

OBJECTIVE

Evaluate the role of chest and abdominal computed tomography (CT) in assessing the severity of acute corrosive ingestion.

METHODS

A retrospective study of adults admitted due to corrosive ingestion, who underwent gastrointestinal endoscopy and CT within 48 h of admission. Endoscopy findings were graded as 0, 1, 2a, 2b, 3a, and 3b (Zargar's criteria), CT findings were graded as 0, 1, 2, and 3. For each patient endoscopy and CT grades were compared, and sensitivity and specificity for predicting mortality or emergency laparotomy were calculated.

RESULTS

Twenty-three patients were included, aged 18-87 years; seven underwent emergency laparotomy, five died. Endoscopy grading was higher than CT grading in 14 patients (66%). The sensitivities of endoscopy grades 2b and 3 to predict mortality and emergency laparotomy were 1 and 0.8, respectively; the specificities were 0.38 and 0.37, respectively. The sensitivities of CT grade 3 to predict mortality and emergency laparotomy were 0.4 and 0.28, respectively; the specificities were 0.94 and 0.93, respectively. Three patients had pulmonary infiltrates on CT but not on chest X-ray. DISCUSSION. CT tends to underestimate the severity of corrosive ingestion compared with endoscopy. It has lower sensitivity and higher specificity than endoscopy in predicting major outcome. CT can provide important information on lung injury, and when endoscopy cannot be completed.

CONCLUSION

CT should not be the only basis for surgical decisions during the initial phase of acute corrosive ingestions.

Determination of urinary hippuric acid in toluene abuse

BACKGROUND

Volatile substance abuse is practiced mainly by adolescents and young adults. Its effects are central nervous system excitation followed by central nervous system depression, at times accompanied by seizures. It may cause sudden death as a result of ventricular arrhythmias, reflex vagal inhibition, respiratory depression, and anoxia. Chronic toxicity may involve the nervous system, heart, kidney, and liver. Toluene-based adhesives are among the most commonly inhaled substances.

CASE REPORT

A 14-year-old female presented with confusion, hallucinations, and intermittent laughing and crying after having inhaled contact glue several times daily in the course of 5 days. Her condition improved within 3 h. Urinary hippuric acid was 93.9 g/g creatinine indicating heavy toluene exposure (biological exposure index, BEI, is 1.6 g/g creatinine).

CONCLUSION

In this patient, urinary hippuric acid was a biomarker for her toluene abuse.

Accidental busulfan overdose: enhanced drug clearance with hemodialysis in a child with Wiskott-Aldrich syndrome

A 4.6 kg infant with Wiskott-Aldrich syndrome received an accidental overdose of busulfan during preparation for allogeneic stem cell transplantation. Pharmacokinetic analysis of plasma busulfan levels alerted staff to the dosing error. Hemodialysis was immediately performed and resulted in accelerated clearance of busulfan. There were no acute neurologic and hepatic side-effects of the busulfan overdose, and despite 2 months of cough accompanied by rales, the patient is now free of pulmonary symptoms. Stable partial donor chimerism occurred after transplantation. At present, the patient is thriving and infection-free 12 months after transplantation, although his platelet count remains at the lower limit of normal.

Ecbalium elaterium (squirting cucumber)--remedy or poison?

BACKGROUND

Ecbalium elaterium is a plant endemic to the Mediterranean basin. Its roots and cucumber-shaped fruit have been used in folk medicine since antiquity. The alleged uses of the fruit juice are as a potent cathartic, analgesic, and antiinflammatory agent. Cucurbitacin B, a triterpene derivative is the active antiinflammatory principal.

PATIENTS

We present a series of 13 patients who were exposed to the juice of Ecbalium elaterium in its natural form. In 3 patients, exposure was intranasal for the treatment of sinusitis or liver cirrhosis. In 3 other cases, children ingested the fruit unwittingly. In 6 patients, exposure was ocular and, in one, dermal. Within minutes of exposure, the patients exhibited irritation of mucous membranes at various degrees of severity manifested as edema of pharynx, dyspnea, drooling, dysphagia, vomiting, conjunctivitis, corneal edema, and erosion, depending on the route of the exposure. Recovery began within several to 24 hours after administration of oxygen, steroids, antihistamines, and beta-2-agonists. Ocular exposures responded to topical steroid and antibiotic eyedrops within a few days. The toddler with the dermal exposure remained asymptomatic.

CONCLUSION

Exposure to the juice of Ecbalium elaterium, mainly in its undiluted form, may cause irritation of mucous membranes, supposedly of inflammatory nature. Patients exposed orally or intranasally should be closely followed for upper airway obstruction. Patients exposed ocularly should have their eyes promptly irrigated to prevent corneal and conjunctival injury.

Severe pulmonary disease in association with Crohn's disease in a 13-year-old girl

Pulmonary manifestations of Crohn's disease are infrequent in adults and even less common in children. Our literature search found only a few cases of Crohn's 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 Crohn's 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.

Poison exposure in children before Passover

BACKGROUND

Extensive cleaning of homes in Israel before Passover may result in increased exposure of children to cleaning substances.

OBJECTIVES

To evaluate the potential danger of Passover cleaning to children, and to study the risk factors in order to identify areas for prevention.

METHODS

All cases of poison exposure in Jewish and Arab children under the age of 15 years reported to the Israel Poison Information Center during 1990-95 (n = 5,583) were analyzed for the 6 weeks before and 6 weeks after Passover. Poison exposures in Jewish children < 15 years old were studied in seven pediatric emergency rooms for the 2 weeks before and 6 weeks after Passover (n = 123).

RESULTS

The IPIC data showed a highly significant 38% increase in the average weekly poison exposure rate for the 2 weeks before Passover compared with the remaining 10 weeks. Data recorded by the pediatric emergency rooms showed a twofold increase in cleaning substance poisoning during the 2 weeks before Passover compared with the following 6 weeks. The rise in exposures to cleaning substances was observed among children from secular, religious and ultra-orthodox families. In these exposures, the substance was found in open containers in 70% of cases.

CONCLUSIONS

The extensive cleaning of homes among Jewish families in preparation for Passover poses the danger to young children of cleaning substance poisoning. Increasing public awareness, closer observation of children, and keeping these substances in closed containers should increase children's safety during this annual cleaning.

Severe pulmonary disease in association with Crohn's disease in a 13-year-old girl

Pulmonary manifestations of Crohn's disease are infrequent in adults and even less common in children. Our literature search found only a few cases of Crohn's 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 Crohn's 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.

The efficacy of oral deferiprone in acute iron poisoning

Due to its high cost and need for parenteral administration, the standard iron chelator deferoxamine is not used in many individuals with acute and chronic iron poisoning worldwide. Deferiprone is the first oral iron chelator to be shown to be effective in chronically iron overloaded thalassemia patients. Its efficacy, by oral administration, in acute iron poisoning has not been tested. Our objective was to determine whether orally administered deferiprone can reduce the mortality of rats following acute, toxic, oral doses of iron. Rats were administered 612 mg/kg elemental iron orally, corresponding to LD50 in the species tested. Two other groups received the same oral dose of iron followed by oral deferiprone: 800 mg/kg and 800 mg/kg, followed by another dose of 800 mg/kg 2 hours later. Coadministration of 800 mg/kg deferiprone with the iron decreased mortality from 30% to 6.6% after 2 hours (P = .02), from 40% to 16.6% after 12 hours (P = .04), and from 53.3% to 20% after 24 hours (P = 0.007). Mortality was also significantly decreased among animals coadministrated 2 repeated doses of deferiprone of 800 mg/kg with iron, to 0%, 9%, and 18%, and 2, 12, and 24 hours postdrug administration, respectively (P = .04, .05, .04, respectively). Histologically, there was a dose-dependent decrease in iron accumulation in the gastrointestinal tract. Orally administered deferiprone can decrease morbidity and mortality caused by acute iron overdose in rats. Oral deferiprone holds promise in the treatment of iron poisoning in humans.

Postmortem digoxin-like immunoreactive substances (DLIS) in patients not treated with digoxin

Endogenous digoxin-like immunoreactive substances (DLIS) cross-react in immunoassays of digoxin. The postmortem rise in digoxin levels in patients treated with the drug may be due to its redistribution. It is unclear what is the contribution of DLIS to this increase and whether DLIS are present postmortem in patients not treated with digoxin. The objectives of this study were to determine whether DLIS are present after death in patients not treated with digoxin, whether a postmortem increase in DLIS is detectable and whether sampling site can affect DLIS concentrations. DLIS (measured as digoxin, TDx Abott) were determined in blood samples drawn antemortem from ICU patients; postmortem samples from femoral artery and cardiac chambers were taken at least 12 h after the death of these same patients. DLIS concentrations > or = 0.2 ng/ml were measured in 44 and 40% of patients antemortem and postmortem (femoral), respectively. No difference was found in DLIS levels between antemortem and postmortem femoral and cardiac samples. Age, ICU stay and postmortem sampling time did not affect the postmortem increase in DLIS. None of the levels was in the toxic range. DLIS may be present after death and their concentration does not increase postmortem. The interpretation of postmortem digoxin concentrations that fall in the therapeutic range should be done cautiously; such measurable levels do not necessarily indicate misuse or malicious intent even in patients who had not been treated with the drug.

Prolonged elimination half-life of phenol after dermal exposure

BACKGROUND

Phenol is a general protoplastic poison which has been in use in medicine and industry for decades. It is readily absorbed through the skin causing both local and systemic toxicity.

CASE REPORT

A 47-year-old male had 90% phenol spilled over his left foot and shoe (3% of body surface area). After a 4 1/2-hour exposure, manifestations included confusion, vertigo, faintness, hypotension, ventricular premature beats, atrial fibrillation, dark-green urine, and tense swelling, blue-black discoloration, hypalgesia, and hypoesthesia of the affected area. Treatment consisted of irrigation with copious amounts of water, incisions, and supportive measures.

RESULTS

Peak serum phenol was 21.6 micrograms/mL, considered in the fatal range. Peak urine phenol plus urine-conjugated phenol was 13,416 mg/g creatinine, indicating a major absorption. Elimination half-life was 13.86 hours, considerably longer than previously reported.

CONCLUSIONS

Prolonged skin contact with concentrated phenol in an occlusive environment may result in a major absorption and a long elimination half-life even if the area involved is small. Prolonged elimination may be explained by extensive tissue distribution or by "slow-release reservoir" properties of the skin. Such exposure may be associated with severe systemic and local toxicities. Immediate removal from exposure and aggressive decontamination of the skin are essential to reduce these risks.

Nitric oxide inhalation for paraquat-induced lung injury

BACKGROUND

When ingested, concentrated paraquat can cause either rapid death from multisystem failure and cardiovascular shock or delayed death from progressive pulmonary fibrosis. Diquat ingestion does not usually cause pulmonary fibrosis, but produces early onset acute renal failure.

CASE REPORT

A 52-year-old male ingested approximately 50 mL of a solution containing 13% paraquat and 7% diquat (about 6650 mg of paraquat and 3500 mg of diquat), and subsequently developed adult respiratory distress syndrome and pulmonary fibrosis. Survival prediction employing the criteria of Hart et al. for paraquat plasma levels was 30%. From the probable amount of paraquat ingested, severe toxicity was expected. The clinical course was not consistent with significant diquat toxicity. Treatment included oral Fuller's earth, forced diuresis, hemofiltration, N-acetylcysteine, methylprednisolone, cyclophosphamide, vitamin E, colchicine, and delayed continuous nitric oxide inhalation. The patient recovered and pulmonary function was subsequently normal.

CONCLUSION

It is unclear which, if any, of the above treatments contributed to recovery, but the encouraging outcome suggests a possible benefit of nitric oxide inhalation in paraquat poisoning which deserves further study.

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.

Severe minocycline-induced eosinophilic pneumonia: extrapulmonary manifestations and the use of in vitro immunoassays

OBJECTIVE

To report a severe and unusual reaction to minocycline and the use of in vitro immunologic assays.

CASE SUMMARY

A 46-year-old white man developed severe respiratory distress with pulmonary infiltrates on chest X-ray and eosinophilia in blood, bronchoalveolar lavage fluid, and biopsied lung tissue during exposure to minocycline. Additional manifestations included pleuropericardial effusion, liver function abnormality, and bone marrow eosinophilia. Macrophage inhibition factor and mast cell degranulation assays were positive to minocycline.

DISCUSSION

The patient's manifestations were compatible with the diagnosis of eosinophilic pneumonia. After excluding other possible etiologies, minocycline was identified as the offending agent. Generalized damage was suggested by the presence of a combination of extrapulmonary manifestations previously not reported. Results of the in vitro immunologic assays supported the hypersensitivity nature of the disease and confirmed the diagnosis.

CONCLUSIONS

Minocycline-induced eosinophilic pneumonia may involve extrapulmonary sites. It is suggested that in vitro immunoassays be used for confirmation of the diagnosis rather than rechallenge or invasive procedures.

The efficacy of calcium gluconate in ocular hydrofluoric acid burns

1. Although calcium gluconate (CG) is recommended in the treatment of hydrofluoric acid (HF) eye burn its efficacy seems to be controversial, and controlled human or animal studies are limited. The study's objective is to compare the efficacy of 1% CG and normal saline irrigation for the treatment of HF eye injury in animals. 2. 0.05 ml 2% HF was instilled to anesthetized rabbit's eyes. One minute later, four treatment groups were studies: (1) irrigation with normal saline followed by topical antibiotics, corticosteroids and cycloplegics for 48 h (n = 10); (2) irrigation with 1% CG followed by the same topical treatment (n = 9); (3) as group 1 and 1% CG drops over 48 h (n = 10); (4) as group 3, and injection of 1% CG subconjunctivally after irrigation (n = 9). 3. Corneal erosion area, corneal haziness, conjunctival status, vascularization (pannus) and acidity were assessed before injury, immediately after initial treatment and 1, 2, 7 and 14 days thereafter by slit lamp aided by fluorescein staining. 4. Conjunctival pH dropped from 6.0-6.5 to 2.5-3 after injury and increased to 6-6.5 after irrigation. Corneal erosion: smaller in groups 2, 3, significantly so at 2 days, but not different at 14 days. Corneal haziness: more severe in group 4, at 14 days, insignificant. Conjunctival damage: significantly worse in group 4 at 2, 7 and 14 days. Pannus appeared in 2-4 eyes in each group. 5. It seems that for HF injury 1% CG did not have any significant advantage over saline irrigation and topical treatment only. It might have some initial and temporary effect on healing process especially that involving erosion. Given subconjunctivally, 1% CG may be toxic and worsens clinical outcome.

Helium and oxygen treatment of severe air-diving-induced neurologic decompression sickness

BACKGROUND

The use of helium and oxygen recompression treatment of neurologic decompression sickness (DCS) has several theoretical advantages over the traditionally used air and oxygen recompression tables that have been confirmed by findings from recent animal experiments.

OBJECTIVES

To evaluate the outcome of patients with neurologic DCS who had been treated with a helium-oxygen protocol and to compare it with that of a retrospective control group that was treated with air-oxygen tables.

DESIGN

The study and control groups included 16 and 17 diving casualties, respectively. The severity of neurologic DCS was estimated according to a 9-point scale weighting motor, sensory, and sphincter control functions. The study group was treated with a helium-oxygen decompression protocol, and the control group was treated with the US Navy air-oxygen Table 6 or 6A. Persistent residual dysfunction was treated in both groups with daily hyperbaric oxygen sessions, at 2.5 absolute atmospheres for 90 minutes, until no further clinical improvement was noted.

SETTING

The Israel Naval Medical Institute (Israel's national hyperbaric referral center), Haifa.

RESULTS

Significant clinical score increments were found for both the helium-oxygen- and air-oxygen-treated groups: 2.8 +/- 2.4 (mean +/- SD) and 7.4 +/- 1.1 at presentation vs 7.6 +/- 2.1 and 8.1 +/- 1.5 at discharge, respectively (P < .001 and P = .005, respectively). Although the score at presentation was significantly lower for the helium-oxygen-treated group (P < .001), no difference was found between the groups' average outcome scores. While most of the improvement in the patients in the study group could be attributed to the helium-oxygen treatment and not to the supplemental hyperbaric oxygen, in the control group, no significant difference could be demonstrated between the scores at presentation and at completion of the air-oxygen recompression table. In 5 patients who were treated with the use of the air-oxygen tables, deterioration was observed after recompression. No deterioration or neurologic DCS relapse occurred in the helium-oxygen-treated group.

CONCLUSION

The results suggest an advantage of helium-oxygen recompression therapy over air-oxygen tables in the treatment of neurologic DCS.

[Hyperbaric oxygen for carbon monoxide poisoning]

Severe cases of carbon monoxide (CO) poisoning from all over Israel are treated at the Israel Naval Medical Institute with hyperbaric oxygen (HBO). Between 1.11.94 and 15.2.95. 24 cases of CO poisoning were treated. Poisoning was usually due to domestic gas-fired heating systems, CO being the only toxin involved. Since delay between termination of CO exposure and arrival at the emergency department averaged 55 minutes, the level of carboxyhemoglobin measured on presentation did not always reflect the true severity of the poisoning. Poisoning was defined as severe and requiring HBO treatment when 1 or more of the following indications was present: evidence of neurological involvement, cardiographic signs of acute ischemic injury, metabolic acidosis, carboxyhemoglobin level greater than 25%, and pregnancy. 20 (84%) recovered consciousness during the course of 1 session (90 min.) of HBO treatment (pO2 2.8 ATA) or immediately thereafter, with resolution of other signs of CO poisoning. 3 required a second treatment session before their symptoms resolved. A patient who arrived in deep coma with severe cerebral edema died. HBO is an important element in the combined treatment of severe CO poisoning. There should be greater awareness of the danger of CO poisoning and the means of preventing it, both among medical staff and the population as a whole, mainly in areas in which cold weather requires use of heating systems, which may be gas-fired.

Delayed administration of Vipera xanthina palaestinae antivenin

INTRODUCTION

Vipera xanthina palaestinae is the most widely distributed venomous snake in Israel, accounting for most envenomations. A specific equine antivenin is efficacious against both systemic and local manifestations if given within hours. This study sought to determine if delayed vipera xanthina palaestinae antivenin can be effective.

METHODS

Patients who had been bitten by vipera xanthina palaestinae during 1991-1995 were evaluated. Those who continued to deteriorate beyond 24 h post envenomation, in spite of treatment or because of delayed diagnosis, were given vipera xanthina palaestinae antivenin.

RESULTS

Ten patients were included in the study. Vipera xanthina palaestinae was identified in seven and diagnosis was considered probable in three patients. On admission, eight patients had local signs and seven patients had mild to severe systemic manifestations. The local signs were remarkable and progressive in all patients. In five, systemic signs and laboratory abnormalities were delayed as well. The time range for delayed antivenin administration was 1-6 days after envenomation. Following antivenin administration, progression of local signs ceased in all patients and swelling regressed within 24 h. In nine patients this occurred within 6 h.

CONCLUSION

Vipera xanthina palaestinae antivenin administration should be considered in patients with envenomations complicated by marked and progressive local signs, delayed systemic signs and laboratory abnormalities more than 24 h after envenomation.

[Hyperbaric oxygen for hydrogen sulfide poisoning]

Hydrogen sulfide (H2S) is a toxic gas produced in decaying substances containing organic sulfur. Exposure to the gas causes severe disturbances in the central nervous and respiratory systems. The mechanism of toxicity is disruption of the electron transport chain in mitochondria, resulting in intracellular hypoxia. Treatment of H2S poisoning includes mechanical ventilation with 100% oxygen and immediate administration of sodium nitrate. Treatment with hyperbaric oxygen (HBO) has been studied in animal models, and has also been used in a number of patients. However, the clinical effectiveness of this mode of therapy has not been clearly proven. Having recently treated a case of H2S poisoning, we suggest HBO to reduce mortality.

Comparison of the pharmacokinetics of 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in healthy volunteers, with and without co-administration of ferrous sulfate, to thalassemia patients

Given the mortality and morbidity associated with acute iron intoxication, effective iron chelation which is easily administered in an emergency situation would be ideal. The pharmacokinetics of L1 were examined in 5 healthy adult male volunteers to assess its potential for use in acute iron overload. Ferrous sulfate (600 mg), L1 (900 mg), and ferrous sulfate and L1 were administered on three separate days, each one week apart. On each test day, blood samples were collected at regular intervals for the measurement of plasma L1 and total iron. Pharmacokinetic values were calculated. The data were also compared to that obtained in 10 patients with beta-thalassemia and chronic iron overload. In the normal volunteers, a 20% decrease in the area under the concentration time curve of plasma iron and of plasma L1 was demonstrated when they were co-administered. There was no change in urinary iron excretion when L1 was given with iron (p = 0.414). The elimination half-life of L1 in the thalassemia patients (137.65 +/- 48.65 min) was significantly longer than that in the healthy volunteers (77.56 +/- 13.0) (p = 0.0047) due to larger apparent volume of distribution. In all of the iron-overloaded individuals L1 resulted in increased urinary iron excretion. None of the other pharmacokinetic variables compared were significantly different between these two groups. These studies indicate that at levels below saturation, transferrin does not allow L1 to remove absorbed iron in healthy volunteers, whereas in thalassemia patients, who are beyond saturation of their iron binding capacity, the drug binds iron and promotes its excretion.

The role of calcium gluconate in the treatment of hydrofluoric acid eye burn

Hydrofluoric acid is used for different purposes in industry and in the home as a rust remover. Most exposures are accidental and may result in severe superficial and deep tissue injury as well as systemic toxicity. There is uncertainty regarding the optimal treatment of hydrofluoric acid eye injury. A patient in whom a solution of 49% hydrofluoric acid induced a large corneal erosion is described. Repeated instillation of 1% calcium gluconate eye drops combined with the conventional treatment of acid eye burns resulted in a complete and quick recovery.

Pharmacokinetics of obidoxime in organophosphate poisoning associated with renal failure

Obidoxime is an oxime used in several countries as an antidote in organophosphate intoxication. Its pharmacokinetics were studied in a 20 year-old female with severe and complicated methamidophos intoxication. Obidoxime elimination half life was 6.9 h, volume of distribution 0.845 L/kg, total body clearance 85.4 mL/min, and renal clearance 69 mL/min (creatinine clearance 54 mL/min). Eighty percent of the dose was excreted in the urine over 5 h. Possible reasons for the different pharmacokinetic values as compared with values previously reported in healthy volunteers are discussed. Obidoxime dose should be adjusted according to renal function. More studies are needed to establish the therapeutic window of obidoxime in patients with organophosphate intoxication.

Atropine poisoning in children during the Persian Gulf crisis. A national survey in Israel

OBJECTIVE

To evaluate the effects of high doses of atropine in children accidentally injected with automatic atropine injectors. These were distributed in Israel during the Persian Gulf Crisis as an antidote for chemical warfare agents.

DESIGN AND SETTING

A national survey in pediatric emergency departments in Israel, involving 22 medical centers, with prospective data collection in 14 centers.

PATIENTS

Children (n = 268) presenting to emergency departments following misuse of automatic atropine injectors.

MAIN OUTCOME MEASURES

Documentation of atropine dose and clinical manifestations; determination of a clinical severity score and its correlation with atropine dose; measurements of serum atropine levels in six patients.

RESULTS

Over a period of 4 months, 268 cases were reported, of which 240 were clinically evaluated. The most common site of injection (75%) was the finger or palm. Doses were up to 17-fold higher than standard doses for age. In 116 children (48%), systemic effects of atropine were observed, and 20 (8%) had severe atropinization. Seizures and life-threatening arrhythmias were not reported, and there were no fatalities. The severity of atropinization was correlated with the dose following a classic nonlinear, dose-response relationship. Serum atropine levels (6.2 to 61.0 ng/mL) were much higher than those observed after administration of therapeutic doses.

CONCLUSIONS

The high incidence of injection in the hand implies accidental use of automatic atropine injectors among children. The lack of mortality or life-threatening complications from injection of large doses of atropine attests to its relative safety in children. The low risk from atropine injections weighed against expected benefit as a lifesaving antidote justifies the distribution of personal atropine injectors to children at risk of organophosphorus nerve agent attack.

[Hyperbaric oxygen for neuropsychiatric sequelae of carbon monoxide poisoning]

A broad range of neuropsychiatric abnormalities, including dementia, psychosis, and parkinsonism, as well as almost every known neurologic syndrome, can occur following carbon monoxide (CO) poisoning. These symptoms develop 2-40 days (usually 2-3 weeks), after initial exposure. There is an incidence of recurrence of up to 40%. However, in recent years the neuropsychiatric sequelae appear to have been occurring less frequently, perhaps as a direct result of the use of hyperbaric oxygen (HBO) therapy. There is no specific therapy for this complication, but up to 75% recover within 12-18 months. Myers et al. (Ann Emerg Med, 14: 1163, 1985) found HBO to be effective for the neuropsychiatric sequelae. We report a 19-year-old man who developed late psychiatric disturbances despite the use of HBO for acute CO intoxication. The neuropsychiatric symptoms, which developed 3 days after full recovery of consciousness, resolved completely when HBO therapy was reinstituted. 6 months later he was functioning normally with no neuropsychiatric symptoms.

Obstructive airway disease associated with occupational sodium hydroxide inhalation

Sodium hydroxide (NaOH) is well known for its corrosive properties and its ability to generate heat on contact with water. The respiratory effects of industrial exposure to NaOH have, however, never been reported. A 63 year old man worked daily for 20 years cleaning large industrial jam containers by boiling lye (NaOH) solution without using respiratory protective equipment. Physical examination, chest x ray film, pulmonary function tests, and arterial blood gases were all compatible with severe obstructive airway disease with significant air trapping. It is probable that this massive and prolonged occupational exposure to the corrosive effect of NaOH mists induced irritation and burns to the respiratory system, eventually leading to severe obstructive airway disease.

Renal handling of cisplatin: interactions with organic anions and cations in the dog

Cis-diamminedichloroplatinum (II) (cisplatin CDDP) is an extremely potent chemotherapeutic agent. Its efficacy, however, is hindered by the cumulative dose-dependent nephrotoxicity which can lead to permanent renal impairment. The mechanisms of the renal transport of cisplatin are not clear. As a first step towards understanding the renal handling of cisplatin we studied its renal clearance in dogs, as well as the effects of organic anion and cation administration on cisplatin. Our results document net tubular secretion of cisplatin. Both an organic anion (probenecid) and cations (quinidine, cimetidine, ranitidine) significantly decreased renal clearance of free CDDP without affecting GFR.

The effects of subcutaneous deferoxamine administration on renal function in thalassemia major

To assess the effects of deferoxamine (DFO) on the kidneys, we studied 27 patients with thalassemia major on chronic subcutaneous (s.c.) DFO therapy. In 41% of the patients glomerular filtration rate (GFR) values were above the normal range. In a previous study similar findings were reported for thalassemia patients who did not receive DFO. The subcutaneous administration of DFO was associated with a clinically significant decrease in GFR in 40% of the patients and in a mild decrease in another 40%. In all cases of severe decreases in GFR, it tended to return to baseline values upon discontinuation of DFO. There was a significant increase in urine volume during DFO therapy. These changes are consistent with our previous observation in humans and dogs receiving high dose i.v. DFO, albeit milder.

The three most common occupational exposures reported by pregnant women: an update

Many uncertainties exist in regard to counseling women with occupational exposures during pregnancy. This is due to limited knowledge of the reproductive toxicologic effects of industrial agents, lack of safety standards aimed at protecting the fetus, and limitations in assessing the extent of exposure. The approach to this subject taken by the Motherisk Program and a review of the three most common occupational exposures are presented. Epidemiologic studies and measurements of radiation do not suggest a reproductive hazard for video display terminals. Exposure to organic solvents is hard to quantitate, and information is sparse and sometimes contradictory, and therapeutic decisions are difficult to reach. To date there is no convincing evidence that working with organic solvents within safety regulations would harm a fetus, in contradistinction to detrimental fetal effects of solvent abuse. The reproductive risks of lead are well documented, fetal exposure can be assessed, and effective treatment exists, but its effects on the pregnancy have not been fully established. However, new evidence suggests that maternal levels that are much lower than the accepted adult limits may be damaging to the fetus.

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.

Exposure to ionizing radiation during pregnancy: perception of teratogenic risk and outcome

We quantified the perception of teratogenic risk in women attending the Motherisk program for counseling about diagnostic radiation in pregnancy (n = 50) and compared it with a control group of women exposed to nonteratogenic drugs and chemicals (n = 48). Before receiving known information about the specific exposure, women exposed to radiation assigned themselves a significantly higher teratogenic risk compared with the control group (25.5 +/- 4.3% versus 15.7 +/- 3.0% for major malformations, P less than 0.01). The post-consultation perception of teratogenic risk did not differ between the two groups. Special consideration and attention should be given when counseling pregnant women exposed to low-dose ionizing radiation, as their misperception of teratogenic risk may lead them to unnecessary termination of their pregnancy.

Deferoxamine (desferrioxamine). New toxicities for an old drug

Iron is an essential 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.

Comparison of oral iron chelator L1 and desferrioxamine in iron-loaded patients

The efficacy of the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1) was compared with that of subcutaneous desferrioxamine in 26 patients with transfusional iron overload. Immediately after red-cell transfusion, 20 patients were randomised to receive either desferrioxamine (50 mg/kg daily as a 12 h subcutaneous infusion), or L1 (50 mg/kg daily by mouth). Patients were evaluated during treatment with the other drug after transfusion the next month. Mean (SD) daily urinary iron excretion was lower during L1 than during desferrioxamine (12.3 [6.7] vs 18.2 [15.3] mg/day). In 5 patients the dose of L1 was raised from 50 to 75 mg/kg daily; mean urinary iron excretion rose from 13.8 (7.0) mg/day to 26.7 (17.8) mg/day, comparable with that during desferrioxamine (24.9 [24.3] mg/day). Faecal iron excretion rose slightly over baseline in 6 patients studied during L1 administration (from 8.5 [0.9] mg/day to 12.2 [0.9] mg/day). Pharmacokinetic studies showed an elimination half-life for L1 of 117-237 min. Studies in dogs and in volunteers showed no absorption of the L1-iron complex, excluding a contribution of absorption of intraluminal complexes of L1 and food iron to urinary iron excretion. Further animal toxicity testing is needed before L1 can be studied in a broader group of patients.

Effect of endogenous digoxin-like substances on the interpretation of high concentrations of digoxin in children

The objective of this study was to assess the effect of endogenous digoxin-like substances on the interpretation of excessive concentrations of digoxin in children. After the development of a high-pressure liquid chromatography (HPLC) method for digoxin in our laboratories, we analyzed sera of children in whom the fluorescence polarization immunoassay identified potentially toxic concentrations of the glycoside (greater than 3 nmol/L; 2.3 ng/ml). Sixteen of them were receiving long-term digoxin therapy, and one had an accidental overdose. The immunoassay yielded significantly higher concentrations (4.1 +/- 1.2 nmol/L; 3.2 +/- 0.9 ng/ml) than the HPLC method (3.3 +/- 1.6 nmol/L; 2.6 +/- 1.2 ng/ml; p less than 0.01). In five cases (30%) these differences were clinically significant because administration of digoxin had been discontinued in the presence of true digoxin concentrations within the therapeutic range and the lack of clinical toxic effects. These data suggest that therapeutic drug monitoring using immunoassays of digoxin may be too inaccurate to detect potential toxic effects, and that much more weight should be focused on clinical monitoring. The HPLC method for assay of digoxin is extremely meticulous and will not become clinically available; therefore the development of better immunoassays should be encouraged.

Comparison of deferoxamine pharmacokinetics between asymptomatic thalassemic children and those exhibiting severe neurotoxicity

The use of deferoxamine for iron chelation in transfusion-dependent thalassemia major is limited by serious neurotoxicity (hearing and vision loss). We assessed whether interpatient variability in handling deferoxamine and resultant accumulation of the drug may account for the neurotoxicity. We studied steady-state deferoxamine pharmacokinetics during intravenous infusion in two groups of patients--one group exhibited severe manifestations of auditory and visual loss and one group was asymptomatic. The groups were matched for age, sex distribution, weight, treatment period, ferritin levels, and hemoglobin levels. Similarly, doses of deferoxamine at the time of the study were not different. Clearance rates were not different between the symptomatic and asymptomatic patients (39.83 +/- 4.54 versus 30.66 +/- 4.39 ml/min.kg). However, patients who exhibited toxicity received significantly higher daily doses of subcutaneous deferoxamine at the time of diagnosis of neurotoxicity (9.03 +/- 0.96 and 5.58 +/- 0.61 mg/kg.hr, respectively; p less than 0.005). These data suggest that deferoxamine induced neurotoxicity is dose-dependent and cannot be attributed to accumulation of the drug caused by slower clearance rates.

The effects of mannitol diuresis on digoxin and phenobarbital handling by the kidney: implications for tubular reabsorption and secretion of the cardiac glycoside

The effect of mannitol diuresis on the renal clearance of digoxin and phenobarbital was studied in dogs. Mannitol diuresis significantly increased the clearance of digoxin and the ratio digoxin: inulin clearances (from 0.7 +/- 0.2 to 1.1 +/- 0.25). The increase in phenobarbital: inulin clearance ratio was significantly higher than the increase in the digoxin: inulin clearance ratio (4.9 fold vs 1.66 fold) (p less than 0.005). Mannitol diuresis did not significantly affect inulin clearance, nor digoxin protein binding during the experimental period while there was a significant increase in PAH clearance. Significant correlations were found between urine flow rate and digoxin renal clearance or digoxin: inulin clearance ratio. The increase in the ratio drug: inulin clearance with diuresis correlated inversely with the initial ratio; animals with more predominant net reabsorption had a higher increase in ratio. These studies suggest that the mannitol-induced increase in digoxin clearance stems from a combination of increased renal blood flow enhancing digoxin secretion, and increased urine flow rate inhibiting its reabsorption. We conclude that urine flow rate and renal blood flow are important determinants of the renal clearance of digoxin, independent of GFR. Any study assessing the effect of pathophysiological states or drug interactions on digoxin renal clearance must control for these factors.

Acute changes in renal function associated with deferoxamine therapy

In three patients who received intravenous deferoxamine there was a twofold to eightfold increase in plasma creatinine level and a parallel decrease in creatinine clearance that resolved when treatment with the drug was discontinued. In two thalassemic patients, diuresis was evident by urine output exceeding fluid intake. The mechanism was studied in dogs that exhibited an acute and significant decrease in inulin and para-aminohippuric acid clearances induced by intravenous deferoxamine. Saline diuresis could prevent the decrease in the glomerular filtration rate but not the decrease in renal blood flow caused by deferoxamine. Deferoxamine induced an acute increase in the fractional excretion of sodium, potassium, chloride, phosphate, and urate, which may explain the relative diuresis observed in two of the patients. In a subsequent experiment, ferrioxamine induced an increase in the fractional excretion of sodium and chloride but did not affect the glomerular filtration rate and renal blood flow. Our studies suggest that adequate hydration may be needed to preserve renal hemodynamics during intravenous deferoxamine therapy. Repeated measurements of renal function should accompany treatment with this agent.

An unusual skin exposure to copper; clinical and pharmacokinetic evaluation

Skin exposure to copper is rare and has been described only with copper sulfate. A case of skin exposure to copper after an explosion of copper azide is presented. The amount of copper absorbed by this route was estimated to be 7.7 mg. Calculated distribution volume was 2.02 I/kg, half-life was 167.4 days and clearance was 0.0058 ml/min/kg. The authors also demonstrated metallic copper to be radiopaque, in contrast to copper salts. It is suggested that copper may be absorbed from the skin even if it is in the metal form. Careful clinical follow up as well as serial determinations of serum copper should guide the need for chelation therapy.

Meso-2,3-dimercaptosuccinic acid in the diagnosis and treatment of lead poisoning

Lead poisoning remains one of the hazards of industrialized civilization. CaNa2 EDTA and dimercaprol, the usual therapeutic measures, have many side effects and can be given by parenteral route alone. The authors present a case of chronic lead poisoning caused by ingestion of contaminated flour ground in a primitive flour mill. The diagnosis was confirmed by the CaNa2 EDTA provocative test. Dimercaptosuccinic acid (DMSA) was given orally as a further provocation and resulted in an 11-fold increase in urinary lead excretion. A 5-day course of treatment with DMSA was instituted, during which symptoms abated, urinary lead excretion increased and the blood lead level decreased. No side effects were noticed. There has been no relapse over several months of follow-up. The authors conclude that the oral use of DMSA is effective, safe and convenient both as a provocative test in establishing the diagnosis of lead poisoning and as a therapeutic tool.

Effect of metoclopramide--a dopaminergic blocker and endogenous cortisol on TSH secretion in critically ill men

In 17 critically ill men, low levels of FT4, TT4, TT3 and elevated levels of rT3 and cortisol were found. In spite of the low levels of circulating thyroid hormones, TSH levels of the critically ill men were significantly lower than those of the control group, with no correlations to the high cortisol levels. After iv injection of metoclopramide (MCP), a dopamine (DA) receptor blocker, the TSH and prolactin (Prl) increments in the critically ill patients were significantly lower than in the controls. No correlation was observed between basal cortisol levels and integrated TSH response to MCP. It is suggested that increased DA tone or high cortisol levels are not responsible for the lower basal TSH levels and for the blunted TSH or Prl responses to MCP in the critically ill. High levels of cortisol may be responsible for the altered TT4 peripheral metabolism to TT3 and rT3 in these patients.

First and second degree atrioventricular block in oxpentifylline overdose

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