Final Exam Toxicology Flashcards

Question

**BB/CCB Pharmacotherapy PT 4 (High-dose insulin euglycemia therapy (HIET))**

Answer 1

**Observe in the ICU until bradycardia, hypotension, EKG abnormalities, and/or CNS Toxicity resolve** **Beta Blockers** Toxicity from regular release beta blockers poisoning typically occurs within the first 6 hours Sotalol: Delayed ventricular dsyrhythmias up to 9 hours post-ingestion Observe PTs who ingest ER preparations for at least 24 Hours **Calcium Channel Blockers** If IR preparation ingestion, ensure that serial EKGs over 6-8 Hours have remained unchanged Observe PTs who ingest ER products for at least 24 Hours, even if asymptomatic

Answer 2

**Cardioactive steroid used for management of supraventricular arrhythmias and heart failure** **MOA:** Inhibition of the Na/K/ATPase pump in myocardial cells Increased intracellular Ca via Na/Ca exchange pump Increased myocardial contractility

Answer 3

**Therapeutic range 0.4-2 ng/mL** Suggestion to lower upper limit 1ng/mL **Clinical presentation** Symptoms Electrolyte abnormalities EKG findings **Timing of Symptom onset** Acute vs chronic toxicity

Answer 4

**Digifab: Digoxin-specofoc antibody fragments** Binds with digoxin to decrease serum digoxin concentration (SDC) Increased Renal clearance of Bound Digoxin **Dosing** Emperic dosing - Acute: 10-20 vials - Chonic: 3-6 Vials Known Amount -Calculate Total Body Load: --Capsules: amount (mg) digoxin capsules ingested --Tablets 0.8 x amount (mg) digoxin tablets ingested -Calculate number of vials needed --Total body load (mg)/0.5

Answer 5

**Acute Toxicity** Single Ingestion of 150 mg/kg **Chronic Toxicity** Less well defined Evaluate in PTs taking more than 200 mg/kg/d (or 10 g/d) in 24H Evaluate in PTs taking more than 150 mg/kg/d (or 6 g/d) in 48H

Answer 6

APAP dose Pattern of use Acute vs Chronic alcohol ingestion Concomitant Medication ingestion Age Nutritional status Presence of Chronic liver disease

Answer 7

**GI Decon with Activated Charcoal** If within 4 hours of acute APAP ingestion May be given after 4 hours if extended-release APAP ingestion of drugs that delay gastric emptying time **Liver Transplant** Lifesaving procedure when APAP ingestion has progressed to irreversible liver failure Qualifying factors: Poor projected outcome and high risk of mortality based on MELD, Kings Criteria, and Apache II scores

Answer 8

**Cysteine prodrug and hepatic GCH precursor** Replenishes and maintains hepatic GCH stores by providing Cysteine, which detoxifies reactive metabolites of APAP May reduce NAPQI back to APAP by enhancing Sulfonation pathway **May reduce mortality from 5% to 0.7%**

Answer 9

**If Normal APAP and Normal AST/ALT do not treat, otherwise _TREAT_**

Answer 10

**Decision to discontinue NAC after extending treatment beyond standard protocol length is PT specific and should be continued if:** Evidence of hepatic injury - AST significantly above normal - PT/INR\> twice normal - Encephalopathy APAP metabolism is incomplete (APAP detectable) **Continue treatment with NAC until evidence of hepatic injury resolves and APAP is undetectable**

Answer 11

**Agents:** Malathion, Parathion, methyl parathion, diazinon **MOA/Mechanism of Toxicity:** Increased concentration of acetylcholine (ACh) at muscarinic and nicotinic cholinergic synapses-\> cholinergic excess

Answer 12

**Atropine MOA:** Competitive antagonist of AcH at muscarinic receptors; reverses excessive secretions, miosis, bronchospasm, vomiting, diarrhea, diaphoresis, and urinary incontinence **Pralidoxime (2-PAM) MOA:** Enhances regen of AChE to lower ACh concentrations and improve muscarinic and nicotinic effects

Answer 13

**Serotonin (5-HT):** Monoamine neurotransmitter synthesized from tryptophan 5-HT1A and 5-HT2A most commonly implicated in serotonin syndrome **Found in the CNS, platelets, and GI tract** CNS: regulates appetite, memory, mood, and sexual activity Peripherally: Assists in regulating clotting, peristalsis, and vascular tone L-Tryptophan -\> 5 Hydroxytryptamine (Serotonin)

Answer 14

Increased Serotonin Production – L-Tryprophan Inhibition of serotonin reuptake – Chlorpheniramine, cyclobenzaprine, dextromethorphan, meperidine, methadone, pentazocine, SSRIs, St. John’s wort, **Tramadol**, trazodone, **TCAs** Inhibition of serotonin metabolism by MAO – **Linezolid**, methylene blue, phenelzine, selegiline Increased serotonin release – Dextromethorphan, meperidine, methadone, MDMA, mirtazapine, **Fentanyl, cocaine, amphetamines** Stimulation of Serotonin receptors – Buspirone, lithium, LSD, Meperidine, metoclopramide, triptans

Answer 15

Diagnosis of exclusion – no confirmatory test Assess exposure to serotonergic drugs in the last 5 weeks Monitor signs/Symptoms of serotonin syndrome Obtain Labs tox screen

Answer 16

Discontinue offending agent Administer IV fluids Control hemodynamic instability Benzo for agitation Implement standard cooling measures for hyperthermia Severe toxicity may warrant sedation, paralysis &/or intubation

Answer 17

Typically resolves within 24H of cessation of serotonergic drug Admit and monitor 12-24 Hrs Concern for delayed cardiotoxicity

Answer 18

**Mechanism of Toxicity** Inhibition of Serotonin and norepinephrine reuptake at nerve terminals Direct a adrenergic block Membrane stabilizing effect Anticholinergic action

Answer 19

**Causative Agents** Amphetamines/Dextroamphetamines/Methamphetamines Methylenedioxymethamphetamine (MDMA/Ecstasy) Synthetic Cathinones (bath salts) Methylphenidate Cocaine

Answer 20

**Not as helpful with isopropanol**