Asia Pacific Journal of Medical Toxicology
Volume:2 Issue: 1, Winter 2013

Acute poisoning is a major public health problem in Bangladesh. It is a common method for suicide. A clear picture regarding clinical presentation, most commonly used toxic agents, background factors and outcome of poisoned patients is necessary in every region. The aim of this study was to investigate frequency and outcome of acute pharmaceutical and chemical poisoning cases in Northern Bangladesh. This was a retrospective descriptive study on poisoned patients with 18 years of age and above who were admitted to Rangpur Medical College Hospital during 1st December 2011 to 30th November 2012. During the study period, a total of 956 patients were investigated. Males slightly outnumbered females (51.6%). The majority of patients (92%) were in the 18-40 year age-group. Regarding occupation, housewives were the most frequent (33.6%) followed by farmers (31.7%) and students (20.9%). Organophosphate compounds (OPC) were the most commonly used toxic agents (73.5%). Most of poisoning cases occurred following suicidal attempts (88%). Familial disharmony was the main cause of suicidal attempts (92.3%). Univariate Analysis showed that age less than 40 years, being married, living in rural areas and educational attainment below secondary level were significantly associated with an increased risk of poisoning (P<0.001). All tertiary hospitals should be well equipped with antidotes of OPCs and other supportive treatments in Bangladesh. Furthermore, strong rules must be applied to prevent the distribution of benzodiazepines without prescription. In addition, people with age of less than 40 years, housewives and farmers, rural residents and those with less educational attainment should be targeted for prevention and educational programs against deliberate self-poisoning.

The role of methadone in QTc prolongation, Torsades de Pointes (TdP) arrhythmia and sudden cardiac death has been debated. Because of widespread use of methadone in methadone maintenance treatment (MMT) centers, we aimed to study dose-related effects of methadone on QTc prolongation. In a comparative observational study, 90 patients who were under MMT were evaluated. Patients were divided into three groups according to methadone daily dose (G1: 0-59 mg, G2: 60-109 mg, G3: 110-150 mg). Twelve-lead electrocardiograms (ECG) were performed at baseline and two months later, after reaching the maximum daily dose of methadone. The QTc were calculated for each patient. Comparison of mean QTc and mean QTc prolongation between baseline and follow up ECGs were analyzed. In total, mean (SD) age was 32.4 (8.5). TdP was not detected in any patients. Mean QTc was 405.2 (17.0) and 418.5 (23.1) msec before and two months after MMT respectively. There was a significant difference between mean QTc in each group before and after treatment (P<0.001). In total, mean QTc prolongation was 13.5 (8.1). Univariate analysis showed that there was a significant difference in means of QTc prolongation between G1 and the other two groups (P=0.001), but not between G2 and G3. This indicates that patients receiving methadone over 60 mg/day are at a risk of greater QTc prolongation. Methadone can cause QTc prolongation in different doses. However, the extent of this effect is dose dependent. Daily dose of less than 60 mg methadone is a safer cardiac dose. Nevertheless, it is not possible to administer this low dose for all opioid addict patients. Therefore, it is necessary to closely monitor patients under MMT, especially those receiving higher methadone doses, with constant scheduled ECGs before and during treatment.

Phenobarbital poisoning is common in Vietnam. The aim of this study was to compare the effectiveness of continuous veno-venous hemofiltration (CVVH) and hemodialysis (HD) on clinical outcomes in the treatment of severe acute phenobarbital poisoning. This was a retrospective observational historically controlled study. 42 patients with severe phenobarbital poisoning were enrolled. 21 patients were treated with HD and 21 with CVVH. Both groups received similar supportive therapies consisting of mechanical ventilation, forced alkaline diuresis and multiple-dose activated charcoal. Following one course of treatment with HD (4 hours) or CVVH (~19.5 hours) the mean (SD) blood phenobarbital concentration (BPC) had decreased to 3.9 (2.5) and 3.2 (2.3) mg/dL respectively (P=0.232). Mean percentage decrease in BPC after HD and CVVH were 62.7 (12.4) and 61.5 (22.0) % respectively, showing no significant difference (P=0.782). Mean duration of coma and mechanical ventilation in CVVH group was 31.9 (26.6) and 39.7 (27.9) hours, significantly shorter than those in HD group with 66.1 (32.5) and 66.7 (32.2) hours (P=0.002; 0.001) respectively. One course of treatment with CVVH and HD decreased the BPC to a similar extent but this was not associated with similar clinical outcomes. Although, CVVH was not associated with rapid fall in blood phenobarbital level, it clearly had clinical advantages by shortening the duration of coma and mechanical ventilation and with lack of coma recurrence in severe phenobarbital poisoning.

Prolonged inhibition of acetylcholine esterase may lead to the intermediate syndrome. Neuromuscular junction (NMJ) dysfunction has been shown with repetitive nerve stimulation (RNS). Subclinical NMJ dysfunction may also occur. We aimed to examine the NMJ function following acute organophosphorus (OP) poisoning by using exercise modified slow RNS. A cohort study was conducted with matched controls. Patients with acute OP poisoning were enrolled. NMJ function, muscle power and tendon reflexes were assessed at discharge and six weeks after exposure. NMJ function was assessed with exercise modified supramaximal slow RNS of the median nerve. There were 68 patients and 71 controls. Mean (SD) age of patients and controls were 32 (12) and 33 (12) years. In some particular amplitude, the decrement response was statistically significant. They were decrement response at rest, at fourth amplitude (95% CI: -0.2 to -2.7) and two minutes post-exercise at fourth and fifth amplitudes (95% CI: -0.8 to -5, -1 to -5 respectively) in the second assessment compared to controls, decrement response at rest at fourth and fifth amplitudes (95% CI: -4 to -0.5, -3.9 to -0.01 respectively) and two minutes post-exercise at fourth amplitude (95% CI: -5 to -0.8) in the second assessment compared to the first assessment. Patients in the first assessment and controls showed more than 8% decrement response either to the second, fourth or fifth stimuli in seven and five occasions respectively. There was no significant neuromuscular junction dysfunction assessed by exercise modified slow repetitive stimulation following acute exposure to OP. Since, NMJ dysfunctions are likely to occur following OP poisoning, other electrodiagnostic modalities such as SF-EMG are probably more efficient to assess these abnormalities

Ingestion of caustic substances is the main reason for referral to Philippines National Poison Management and Control Center among other causes of acute poisoning. Rapid assessment of severity of injury is important for treatment and prognosis of these cases. This study was aimed to investigate the correlation of clinical factors with severity of gastrointestinal (GI) mucosal injury. In this retrospective study, a total of 105 patients were included. Patients were categorized into two groups including 35 patients with low grade and 70 patients with high grade GI injury to compare the predictive value of clinical findings. Mean (SD) age of patients was 27 (10) and 47% of patients were male. Oral burns (P<0.001), dysphagia (P=0.001), hematemesis (P<0.001), number of presenting symptoms (P=0.001), and type of substance consumed (P<0.001) were significantly different between patients with high grade and low grade GI injuries. Multivariate analysis showed that only leukocytosis was a significant predictor of higher grades of GI injury (OR=17.3, P=0.004). Nevertheless, dysphagia (OR=8.1), and higher number of manifestations (OR=2.8) on initial evaluation could be considered as weak factors as they did not reach significance (P=0.09). Following caustic substance injury, prompt assessment of severity of GI injury according to endoscopic and physical examinations can facilitate better treatment plan and prognosis. Patients with leukocytosis should be more carefully monitored as they might be injured with higher grades of GI mucosal lesions.

Organophosphorus (OP) poisoning is a major public health problem in developing world. OP pesticides inhibit carboxylic esterase enzymes including plasma cholinesterase (PChE). Clinical manifestations following OP poisoning can be associated with the extent of decrease of PChE. This study was designed to investigate the relevance of PChE level to clinical manifestations in OP poisoning and to evaluate usefulness of PChE in predicting clinical outcomes. This was a cross-sectional study which was conducted at Jawaharlal Nehru Medical College, Karnataka from 1st October 2009 to 30th September 2010. Seventy-six OP poisoned patients were enrolled and their clinical manifestations were recorded. 5-ml samples of intravenous blood were collected from each patient (on first day and fifth day of treatment) under strict aseptic precaution and the PChE level was measured. In total, mean age of patients were 25.5 (range: 21-30) years. Majority of patients were males (65.7 %), from rural areas (86.84 %) and agricultural workers (25%). Main clinical findings at the time of admission were congested conjunctiva (87%), pin point pupil (83%), lacrimation (80%), vomiting (78%), non-reactive pupil (75%), respiratory distress (60%) and abdominal pain (37%). Mean (SD) PChE at 6 hours post-exposure was 3672.4 (4200.1) IU/L. At presentation, cyanosis, muscle weakness, convulsion, respiratory distress and fasciculation were related to cases with >75%reduction of PChE, while, constricted and non-reactive pupil, lacrimation and congested conjunctivae were related to cases with 50-75% reduction and abdominal pain, dryness of conjunctiva, vomiting and diarrhea were related to <50% reduction. Deceased cases had the lowest mean PChE level at presentation (1270.2). Death was mostly observed among patients who had respiratory distress. A relative relationship between PChE level and clinical manifestations and outcomes was found. These findings can assist health professionals to better evaluate patient’s prognosis and improve their treatment plan.

Most drug overdoses are due to suicidal attempts. This study was designed to analyze the risks and risk factors of poisoned patients with repeated suicidal attempt in Iran. This case-control study was conducted at Loghman Hakim Hospital, Tehran, Iran, during April to May 2008. Eighty-seven patients who were admitted due to drug overdose with loss of consciousness were enrolled. Patients were categorized to cases including 19 patients with history of previous suicidal attempt (repeated suicidal attempt), and controls including 66 patients without this history. Only patients who consumed drugs for self-harm were included. Demographic characteristics, past medical history, baseline physical examinations, dose and class of drugs used were recorded. History of previous suicidal attempt had a significant association with the type of drugs used for poisoning (P=0.04) and history of psychological disorders (P<0.01). Dose of ingested drugs (P=0.020), time interval between drug ingestion and emergency medical service arrival (P=0.021), severity of unconsciousness (P=0.046) and need for ICU care (P=0.013) were significantly higher in patients with repeated suicidal attempt. There was no significant difference between the two groups in terms of age, gender and history of illicit substance abuse. According to these findings, when dealing with patients with loss of consciousness due to drug overdose, those with history of previous suicidal attempt are in more risks and need significantly more attention compared to those without such history. Considering history of previous suicidal attempts in poisoned patients can help medical professionals in determining more definitive prognosis and more effective treatment plan.

Toxic contamination of fish may compromise food safety. Haff disease is a rare syndrome characterized by rhabdomyolysis following consumption of cooked, freshwater fish. Case Report: A healthy 42 year old female presented three hours after eating fried buffalo fish (Ictiobus cyprinellis). Her symptoms began while eating the fish, described as diffuse muscle aches followed by generalized muscle fatigue, most pronounced in her proximal lower extremities. Vital signs were normal. Her physical exam was notable for diffuse muscle tenderness and difficulty standing. Baseline complete blood count and chemistries were normal, but serum creatine phosphokinase (CPK) was 12,777 U/L. Alanine aminotransferase and aspartate aminotransferase were 268 U/L and 1431 U/L respectively. She was treated with aggressive hydration, sodium bicarbonate, and oral N-acetylcysteine. The serum CPK peaked at 76,364 U/L, twenty hours post-exposure. Her creatinine remained normal. Over the next 5 days the CPK slowly resolved. Haff disease is a rare syndrome characterized by rhabdomyolysis following consumption of certain cooked, freshwater fish. Although the exact toxin has yet to be identified, this disorder is felt to be caused by a heat-stable toxin contaminating certain fish. Our case was unique due to the immediate onset of symptoms and the extremely high serum CPK levels. Haff disease may result in the rapid onset of severe rhabdomyolysis. Aggressive treatment with fluids and bicarbonate prevented renal damage in this case. Because cases may occur outside of endemic areas, fish consumption should be included in the history for any case of rhabomyolysis of unknown etiology. Suspected cases of Haff disease should be reported to local public health authorities and samples collected for analysis.