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181-196 of 196 results by Fermin Barrueto
Opioids Opioids in general cause respiratory depression, miotic pupils and some mild hypotensions and bradycardia when the patient is comatose. All opioids can cause varying degrees of histamine release. However, not all opioids are similiar, here are the unique toxicities of some various opioids - keep them in mind when you prescribe them: 1) Propoxyphene - seizures and TCA like effects, also not very effect analgesic 2) Meperidine - seizures, serotonergic (thus increased abuse potential) 3) Methadone - long half-life (30+hrs) and QT prolongation 4) Hydromorphone - rare seizures and most common opioid that causes iatrogenic overdose because of its potency. (Easy to write 2 mg of "Dilaudid" but that is equivalent to 14 mg of morphine!) 5) Tramadol - seizure (common) and serotonergic, this is only 20% opioid 6) Fentanyl - rigid chest syndrome with rapid IV administration causes intercostal muscle contraction - not good
Chemical Weapons of Mass Destruction There are a variety of chemicals utilized as WMD and can be categorized as: nerve agent, blistering agent or incapacitating agent: Nerve Agents: (Sarin, VX) cause a parasympathetic toxidrome due to inhibition of Acetylcholinesterase. Antidote is pralidoxime, benzodiazepines and atropine. Blistering Agents: (Mustard Gas) Must be treated like a severe burn patient causing extreme pain and sloughing of the skin. Incapacitating Agents: (BZ) Causes anticholinergic toxidrome, your whole army starts to hallucinate and develop urinary retention. People armed, hallucinating and needing to pee makes for a highly ineffective military force.
Gastrointestinal Decontamination - Activated Charcoal Pharmacist P.f. Touery, in 1831, making a demonstration of the effectiveness of charcoal before the French academy of Medicine, survived after swallowing 15 g of strychnine (10x lethal dose) and an equal amount of charcoal - 3 tablespoons. (That's for you Dr. Rolnick) - Assess the patients' chance of becoming unresponsive or vomiting in relation to the ingestion if known. - Maximal benefit if given within 1 hour of ingestion, drug is likely still in the stomach. - No study has yet to show decrease in morbidity or mortality when empirically given to all ingestions. - Only one study has shown multi-dose activated charcoal to decrease morbidity and mortality and that was with a drug (oleander is like digoxin) that is enterohepatically metabolized. de Silva HA, et al. Multiple-dose activated charcoal for treatment of yellow oleander poisoning: a single-blind, randomised, placebo-controlled trial. Lancet. 2003 Jun 7;361(9373):1935-8.
One Pill Killers for Children Drug Class Mechanism of Action that Kills Sulfonylureas These hypoglycemic agents (ie. Glyburide) also have a long t Opioids Respiratory depression Imidazoline Clonidine and Oxymetazolone (nasal spray) cause bradycardia and respiratory depression Ca Channel Blockers Bradycardia & hypotension, especially diltiazem and verapamil Beta Blockers Extended release preparations are problematic There are some others but these are the most commonly prescribed pharmaceuticals. Remember, children under age 6 will not be able to swallow a pill and the pill itself is choking hazard. Proper poison prevention education for the parents is also needed.
Heavy Metal Poisoning Clues for Diagnosis Mees lines, indication of arrested nail growth, occurs in lead, arsenic and others Most heavy metals will cause a proteinuria Microcytic anemia and basophilic stippling seen in lead, arsenic, mercury Peripheral neuropathies in otherwise healthy person Thallium causes classic painful paresthesias in lower extremities
Cyanide Presents with arterialization of venous blood (venous blood draw looks like ABG) Reason: o Hemoglobin is not able to offload oxygen o CN poisons cytochrome c oxidase preventing conversion of oxygen to water and thus production of ATP Old antidote: sodium thiosulfate New antidote: hydroxycobalamin binds CN producing cyanocobalamin (Vit B12) When you give it expects a dip in pulse because of its blue color. Remember CN will give you a beautiful 100% pulse all the way to death. Lee J, et al. Potential interference by hydroxocobalamin on cooximetry hemoglobin measurements during cyanide and smoke inhalation treatments. Ann Emerg Med. 2007 Jun;49(6):802-5. Epub 2007 Jan 8.
Hydrofluoric Acid (HF) Used in glass etching, brick/porcelain cleaning and available in hardware stores Death has been reported after JUST 2-3% body surface area exposure! Systemic toxicity: hypocalcemia, hyperkalemia and hypomagensemia Local effects: paucity of skin findings with tremendous pain Treatment: skin decontamination, correct electrolyte abnormalities and topical calcium gel for local pain Mayer TG, GrossPI. Fatal systemic fluoride due to hydrofluoric acid burns. Ann Emerg Med 1985; 14: 149-153.
Toxic Alcohols Unexplained anion gap metabolic acidosis => give fomepizole (antidote) Hypokalemia, hypocalcemia, elevated creatinine => think ethlylene glycol Visual disturbances => think methanol Ketosis without acidosis and high osmol gap => think isopropanol If osmol gap is >70; high specificity for a toxic alcohol ingestion
Acetaminophen Toxicity Hepatoxicity defined by AST >1000 King s College Criteria to prognosticate hepatic failure and need for transplant: o pH <7.3 o Creatinine >3.4 mg/dL o INR >6.5 o Hepatic encephalopathy Grade III or IV Low phosphate (<1.2 mmol/L) may be predictor of survival and elevated may be indicator of impending hepatic failure. (Especially 48 96 hrs post-ingestion) o Theory is phosphate used in regeneration/healing liver Gow PJ, Sood S, Angus PW. Serum phosphate as a predictor of outcome in acetaminophen-induced fulminant hepatic failure. Hepatology. 2003; 37(3):711.
Botulinum Toxin Most potent toxin on the planet where 7 picograms IV are lethal to a human Characterized by a descending flaccid paralysis w/o fever bulbar findings 1st Weapon of Mass Destruction but also seen in the IVDA Heroin population Black Tar Heroin outbreak with necrotic ulcers that produced C. botulinum o Most recently in Washington DC 2003 Centers for Disease Control and Prevention (CDC). Wound botulism among black tar heroin users--Washington, 2003. MMWR Morb Mortal Wkly Rep. 2003;52(37):885-6.
Diagnosing Salicylate Toxicity - Acute ingestion can initiially present with nausea, vomiting and a respiratory alkalosis - Toxicity defined by an anion gap metabolic acidosis with ketosis and normal glucose - Ferric chloride test (can get from chemistry set): couple of drops into urine, if it changes color to deep purple sensitive positive for presence of salicylate (sensitive but not specific)
Lithium Toxicity Management Initial Therapy: 2x maintenance fluid with normal saline Hemodialysis is controversial but will remove lithium quickly Association of permanent neurologic sequelae with elevated lithium level(1) o Looks like a cerebellar stroke 1- Adityanjee. The syndrome of irreversible lithium-effectuated neurotoxicity (SILENT). Pharmacopsychiatry. 1989 Mar;22(2):81-3.
Digoxin Toxicity Most common finding on ECG when digoxin toxic: PVCs Most classic ECG in digoxin toxicity: PAT with block Pathognomonic finding (RARE): Bidirectional ventricular tachycardia Easy formula for administration of digoxin specific Fab (Digibind?? or DigiFab?). Remember to round up even if its 2.3 vials, give 3. [(Dig Serum Concentration(ng/mL)) x wt(kg)] / 100 = # vials
Tricyclic Antidepressants (TCA) - Lack of terminal 40msec R wave (R wave in AvR, S wave in I, AvL) means the patient is NOT TCA toxic. - 40msec R wave + QRS >100msec = possible TCA toxicity, treat with NaHCO3 and recheck ECG. - TCA toxicity defined by ECG; if QRS > 100msec, 33% seizures; if QRS > 160msec, 50% v tach Boehnert MT, Lovejoy FH Jr. Value of the QRS duration versus the serum drug level in predicting seizures and ventricular arrhythmias after an acute overdose of tricyclic antidepressants. N Engl J Med. 1985 Aug 22;313(8):474-9.
Urine Drug Screens Though we order them often, be sure you know what your results mean: Cannabinoids: an accurate test though clinically not important information, positive for 5 days to a full month with chronic users. Cocaine: the most accurate and precise test, positive for 3-5 days. Amphetamine: the most imprecise with many false positives and false negatives. Cough/cold preparations that contain pseudephedrine, phenylephrine or other decongestants can turn it falsely positive. BDZ: only benzodiazepines that are metabolized to oxazepam will turn positive. You can see false negatives with alprazolam and even lorazepam. Opioids: Semisynthetics like oxycodone and hydrocodone may give false negatives at low levels. This screen will NOT catch methadone, meperidine, fentanyl, propoxyphene, tramadol. PCP: False positives from dextromethorphan and ketamine