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281-300 of 550 results with category "Toxicology"
Hyperglycemia in the setting of antipsychotic use has been reported mostly with olanzapine (Zyprexa) but does occur with other antipsychotics. A recent study from the NYC medical examiner's office details 17 deaths of DKA due to antipsychotics and found that (from highest to lowest incidence) quetiapine > olanzapine > risperidone were the atypical antipsychotics found with these deaths.
Remember hyperglycemia occurs with patients on antipsychotics and can lead to hyperglycemia hyperosmolar coma or DKA. Both can be lethal.
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Utilizing 20% lipid emulsion at a dose of 1.5 mL/kg (100 mL Bolus) IV with repeat in 15 minutes in no response is being recommended in patients hemodynamic instabiity due to poisoning.
Probably more effective in lipophilic drugs is a current theory for the mechanism of action - the "lipid sink". The idea is that the lipids envelope the drug pulling it off its receptors or sequestering it in the intravascular space. A recent paper has added another mechanism - direct inotropic and lusiptropic effects.(1)
Also, if you think the therapy is experimental, think again. Another recent paper surveyed Poison Control Centers and found 30/45 Poison Centers in the US have a defined protocol for utilization of lipid emulsion therapy. The PCCs are recommending it more.(2)
What was once considered just a purely experimental therapy only used at the very end of code is becoming more mainstream. Comfort with its safety profile and anectodotal effiicacy continues to mount.
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Strychnine poisoning is still occasionally found in rat poisons and in adulterated street drugs and herbal products. The typical symptoms are involuntary, generalized muscular contractions resulting in neck, back, and limb pain. The contractions are easily triggered by trivial stimuli (such as turning on a light) and each episode usually lasts for 30 seconds to 2 minutes, for 12 to 24 hours. Classic signs include opisthotonus, facial trismus, and risus sardonicus.
Differential diagnosis includes:
- Tetanus: However, the onset of symptoms is more gradual and the duration much longer than in the case of strychnine poisoning.
- Generalized seizures: However, strychnine poisoning presents with a normal sensorium during the period of diffuse convulsions.
- Dystonic reaction: However, dystonic reactions are usually static, whereas strychnine poisoning results in dynamic muscular activity.
- Serotonin syndrome
- Malignant hyperthermia
- Neuroleptic malignant syndrome
- Stimulant use
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If you are working in a community hospital and have an acetaminophen overdose, one of the criteria to transfer the patient to a tertiary care center is presence of the King's College Criteria.
The below is taken from mdcalc.com - http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/
Each one is assigned points and can be prognostic for severe toxicity and need for transplant. The lactate and phosphorus are new ones and have modified the criteria. Phosphorus is utilized to create glycogen. If the liver is injured and trying to heal, your phosphorus will be low (good). If the liver is injured and unable to repair itself the phosphorus will be high (bad). This single test has an excellent prognostic ability.
| Lactate > 3.5 mg/dL (0.39 mmol/L) 4 hrs after early fluid resuscitation? | |
| pH < 7.30 or lactate > 3 mg/dL (0.33 mmol/L) after full fluid resuscitation at 12 hours | |
| INR > 6.5 (PTT > 100s) | |
| Creatinine > 3.4 mg/dL (300 µmol/L) | |
| Grade 3 or 4 Hepatic Encephalopathy? | |
| Phosphorus > 3.75 mg/dL (1.2 mmol/L) at 48 hours |
With recent events, a few notes about ricin seems appropriate:
- Easy to make from castor bean though heat labile
- No antidote, though Fab like digibind is in development
- Granule size of the grain of sand can kill
- Inhalation, IM, IV all effective
- After immediate exposure likely no symptoms
- Vomiting and diarrhea initially, acute lung injury and death in 3-5 days
CDC website: http://www.bt.cdc.gov/agent/ricin/
Methods: A large retrospective case series evaluated 121 children under 6 years old with hypoglycemia from a sulfonylurea ingestion.
Results:
- In addition to dextrose, patients who received octreotide had a median of zero hypoglycemic episodes after octreotide (compared to 2 before treatment, p < 0.0001).
- Median blood glucose concentrations after receiving octreotide were also higher (62 mg/dL vs 44, p < 0.001).
- Most required only 1 dose of octreotide with no reported adverse effects.
Authors' Conclusion: Octreotide administration decreases the number of hypoglycemic events and increases blood glucose concentrations in children with sulfonylurea ingestion.
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Cocaine toxicity is characterized by the sympathomimetic toxidrome: tachycardia, hypertension, hyperpyrexia, diaphoresis as well as sodium channel blocking effects that can cause local anesthesia topically, QRS widening and even seizure.
Usual treatment for a cocaine toxic patient is benzodiazepines and cooling. Be wary of end organ damage, trauma and seizures.
There was a recent study that looked at dexmedetomidine to treat the sympathomimetic effects. Placebo-controlled trial used cocaine-addicted volunteer and applied intranasal cocaine. Measuring skin sympathetic nerve activity and skin vascular resistance, this study, unfortunately, showed as the dose increased MAP did not fall further and increased paradoxically in 4 of 12 subjects.
This highlights the incredible physiologic mechanism of catecholamine release from the CNS with cocaine. This mechanism overlaps some with the centrally acting alpha agonist - dexmedetomidine and was shown in the study by Kontak et al.
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In 2013, the American Academy of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists published a second update to their position statement on gastric lavage for GI decontamination (original 1997, 1st update 2004).
- Gastric lavage should not be performed routinely, if at all, for the treatment of poisoned patients.
- Further, the evidence supporting gastric lavage as a beneficial treatment even in special situations is weak.
- In the rare instances in which gastric lavage is indicated, it should only be performed by individuals with proper training and expertise.
Bottom line: Gastric lavage generally causes more harm than good. It should not be thought of as a viable GI decontamination method.
Bonus: Dr. Leon Gussow (@poisonreview) reviews the position paper on his blog, The Poison Review, here: http://www.thepoisonreview.com/2013/02/23/gastric-lavage-fuggedaboutit/
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Question
A foley is inserted in a fire victim patient. Urine return is in picture. Describe the reason for this colored urine.
Special Thanks to Dr. Doug Sward for the urine picture
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Typical opioid withdrawal include clinical symtpoms of piloerection, nausea, vomiting and diarrhea. If you were to see seizure, another etiology other than opioid withdrawal should be investigated.
Except in the case of neonates borne to women who have been taking opioids chronically such as a methodone patient. Once the child is born, symptoms of withdrawal may take days to weeks to materialize though seizures typically occur <10 days. The child is at increased risk of SIDS as well.
Most antidotes have not been adequately studied in pregancy and hold a Pregnancy Risk Category 'C' by the FDA. However, there are a few antidotes that hold a category 'D' or 'X' rating (contraindicated).
- Ethanol (toxic alcohols) - Category C
- Reproduction studies have not been conducted with alcohol injection. Ethanol crosses the placenta, enters the fetal circulation, and has teratogenic effects in humans. When used as an antidote during the second or third trimester, Fetal Alcohol Syndrome AS is not likely to occur due to the short treatment period; use during the first trimester is controversial.
- Alternative (preferred) antidote: fomepizole.
- Methylene blue (methemoglobinemia) - Category X
- Use during amniocentesis has shown evidence of fetal abnormalities, but it has been used orally without similar adverse events. IV may be ok.
- Lorazepam and diazepam (seizures, nerve agents) - Category D
- Teratogenic effects have been observed in some animal studies and in humans. Lorazepam/diazepam and their metabolite cross the human placenta.
- Potassium iodide (radioactive iodine) - Category D
- Iodide crosses the placenta (may cause hypothyroidism and goiter in fetus/newborn). Use for protection against thyroid cancer secondary to radioactive iodine exposure is considered acceptable based upon risk:benefit, keeping in mind the dose and duration.
- Amyl nitrite (cyanide) - Category C (manufacturer contraindicates)
- Animal reproduction studies have not been conducted. Because amyl nitrate significantly decreases systemic blood pressure and therefore blood flow to the fetus, use is contraindicated in pregnancy (per manufacturer).
- Other options exist to treat cyanide exposure including sodium nitrite, sodium thiosulfate, and hydroxocobalamin.
- Penicillamine (chelator) - Category D
In most cases, the benefits of short-term use probably outweigh the risk, especially when accounting for the health and prognosis of the mother.
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There have been many attempts to reduce the incidence of contrast-induced nephropathy. Mechanism usually centers around antioxidant properties or free radical scavengers that prevent the acute kidney injury that may result after intravenous contrast. IV Fluid hydration, sodium bicarbonate and acetycysteine have been studied with only some evidence. There is also some controversial data that is beginning to surface regarding the use of atorvastatin with a recent article in Circulation 2012 that showed high dose atorvastatin (80mg) 24 hrs prior to angiography prevented contrast-induced acute kidney injury in patients with mild to medium risk. Link to article has been provided:
http://circ.ahajournals.org/content/126/25/3008
Cyclophosphamide-induced hemorrhagic cystitis is a well known to oncologists. This unique complication of this chemotherapeutic drug has a defined mechanism and could be seen in your Emergency Department.
- Hemorrhagic cystitis occurs in 46% of patients that receive cyclophosphamide
- Can occur even months after administration
- 5% can actually die from the hemorrhage
- Treatment: Bladder irrigation, hydration, supportive. Oral adminsitration of MESNA (2mercaptoethan sulfonate) and bladder irrigation with prostaglandins and even methylene blue have been attempted.
SSRIs and SNRIs like venlafaxine and sertraline are well known to cause hyponatremia. Usually considered safe, this adverse drug event can lead to weakness, confusion, seizure and even cerebral edema. Elderly are more susceptible to this adverse effect.
ADH is regulated by serotonin and thus the mechanism for the Hyponatremia is SIADH.
Tolvaptan, a vasopressin receptor antagonist, has been a new treatment that has been used anecdotally in Europe. Waiting for the first US case report.
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Several medications can produce a false-positive result for methadone on the urine drug screen: diphenhydramine, doxylamine, clomipramine, chlorpromazine, quetiapine, thioridazine, and verapamil.
Add a new one to the list. Tapentadol, a relatively new opioid analgesic similar to tramadol, can also produce a false-positive result for methadone on certain immunoassays.
A separate study concluded that tapentadol does not affect the amphetamine screen.
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Creatine
- is the most popular nutritional supplement, accounting for $400 million in sales annually
- a nonessential amino acid
- has been shown to improve performance in short, high intensity exercises, including weight lifting
Adverse effects: weight gain, edema, GI cramping, fatigue and diarrhea
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Despite a paucity of data, pain management clinics are administering topical gel mixtures that have included ketamine, tricyclics, calcium channel blockers and baclofen. Internet blogs have already identified this gel mixture as a way to "get high". This is one of those google searches you have to do on your own.
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Myth: The ornamental red plant - poinsettia - gained a reputation as a poisonous plant from a case report. In 1919, a 2-year-old child reportedly died from an ingestion and later an 8-month-old developed mucosal burns. These anectdotal case reports perpetuated the myth that poinsettia plants are poisonous. In the modern literature there is one single case of anaphylaxis(1) due to poinsettia ingestion/exposure, an allergic dermatitis(2) and one case of dermatitis(4).
Krenzelok et al.(3) showed there were 22,793 cases of poinsettia exposure and there were no fatalities reported to poison centers. 96.1% were kept at home without sequelae.
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The more well known causes of toxin-induced hyperthermia include sympathomimetics and anticholinergics. In addition, neuroleptic malignant syndrome, serotonin syndrome, and malignant hyperthermia are high on the differential.
Several other xenobiotics can cause hyperthermia in overdose as well:
- Salicylates and dinitrophenol cause hyperthermia by uncoupling oxidative phosphorylation.
- Thyroid medications cause hyperthermia via thyroid hormone's thermogenic effect and psychomotor agitation. Hyperthermia can be extreme (>106°F, >41°C).
- Caffeine/theophylline, isoniazid, and strychnine cause hyperthermia through refractory seizures and muscle contraction. Highest temp recorded with strychnine is (109.4°F, 43°C).
In general, benzodiazepines should be considered first-line therapy, followed by barbiturates, propofol, or other sedative hypnotics. Phenytoin rarely has a role in the management of toxin-induced seizures. Extrenal cooling measures are also warranted. Specifically for isoniazid, pyridoxine should be administered immediately with a benzodiazepine.