toxicology juju Flashcards by Juju Go

What is therapeutic drug monitoring?

Measuring conc. of a drug/metabolites in order to optimize the dosing to patient/ assess compliance w dosing schedule
optimum dosing: improves drug therapeutic effect while avoiding side effects/toxic effects
check: blood serum/plasma, urine
Used to find appropriate dosing for conditions such as renal dysfunction, pregnancy, newborns, geriatric pts

Use TDM with drugs with:
- A narrow TI
- significant side effects
- low margin of safety

How well did you know this?

Not at all

Perfectly

What are the indications for drug monitoring? clinical, legal, forensic

Clinical:
- Overdose
- Therapeutic Monitoring

Legal: workers comp

Forensic:
- COD
- DUI
- athletic testing
- employment testing

How well did you know this?

Not at all

Perfectly

What are the forensic indications for drug monitoring?

COD
DUI
athletic testing
employment testing

How well did you know this?

Not at all

Perfectly

What are trough concentrations used for

To see when due for next dose

How well did you know this?

Not at all

Perfectly

Therapeutic Drug monitoring can be done through

Blood serum plasma urine

How well did you know this?

Not at all

Perfectly

When are peak concentration of most drugs

30-60 min post dose

How well did you know this?

Not at all

Perfectly

Pharmacokinetic Principles

*LADME
*L- Liberation : how the metabolite becomes available in the body
*A- Absorption: movement into circulation
*D- Distribution: body tissues
*M- Metabolism: conversion of drug to active
*E- Elimination

How well did you know this?

Not at all

Perfectly

Alcohols description

Can be acute intoxication or chronic abuse (Pancreatic disease, Liver cirrhosis)
- peak is 30-75 min post ingestion
- 1 oz liquor, 4 oz wine, 12 oz beer→25-30 mg/dL
- clearance rate: 15- 25 mg/dL/hour (clear up in an hr in normal body non alcoholic)
- screened for via BREATH TEST AND BLOOD TESTS***
- screen for alcohol in pregnancy: AVOID
- metabolism: differs person to person

How well did you know this?

Not at all

Perfectly

What tests for alcohol?

Breath Test & Blood Test

How well did you know this?

Not at all

Perfectly

Alcohol peak?

30-75 post ingestion

How well did you know this?

Not at all

Perfectly

Alcohols: methanol, ethylene glycol, isopropanol

Methanol
- (MUDPILES)
- moonshine
- washer fluid
- sx: imparired vision - blindness*, seizures, vomit, coma

Ethylene glycol:
- antifreeze
- sx: anuria*, vomit, seizures, coma

isopropanol:
- rubbing alcohol
- sx: hematemesis, melena, abdominal pain, vomit, coma

all of them: vomit, coma

How well did you know this?

Not at all

Perfectly

Ethylene Glycol poisoning symptoms

Anuria, vomiting, seizures, coma

How well did you know this?

Not at all

Perfectly

Isopropanol poisoning symptoms

Vomiting, abdominal pain, hematemesis, melena, coma

How well did you know this?

Not at all

Perfectly

Methanol associated with

Moonshine, washer fluid

sx: impaired vision-blindness, vomitting, seizures, coma

How well did you know this?

Not at all

Perfectly

Methanol poisoning

Impaired vision, blindness, vomit, seizure ,coma

How well did you know this?

Not at all

Perfectly

Occupational Environmental Toxins + sources of contamination

-Heavy metals
-Gases
-Caustic compounds

contamination sources:
- soil
- ground water

Examples of environmental toxins

-Carbon monoxide
-Mercury
-Cyanide
-Insecticides
-Lead

Carbon monoxide deaths per year?, leading cause of what?

4,000 deaths per year, leading cause of accidental & deliberate poisoning (inside the car)

With carbon monoxide poisoning there is binding to?

Binding of Carbon monoxide to oxygen binding sites on hemoglobin
- can have 50% drop

Carbon monoxide poisoning: adults vs kids

Adults:
- headache= MC sx**
- heart: MI
- lungs
- CNS: permanent neurological impairment
- vision
- hearing
- peripheral nerve conduction

Kids: mimics Gastroenteritis**
- diarrhea, N/V
- Fetal hb has different binding capacity so infants may not be as affected as adults

What can children presentation of carbon monoxide poisoning mimic?

gastroenteritis

Carboxyhemoglobin Relative to Total Hemoglobin (%) - ranges: nonsmoker, smoker, sx associated

nonsmoker normal range: 0.1-0.9 smoking: 1.5-10
10-30: increasingly severe headache, dyspnea on exertion
40-50: + tachycardia, may be fatal
60-70: coma, seizure, often fatal
80: rapidly fatal

Lead poisoning primarily effects

Primarily affects children (greater than 5 µg/dL in blood)
Pediatric screening :done at 1 year old & 2 years old
labs shows CBC microcytic anemia-LOW hct
Impairs cognition and behavior causing: seizures, mental retardation, chronic behavior dysfunction, anemia, renal toxicity, recurrent vomiting and abdominal pain.

What is impaired with lead poisoning?

-Impaired cognitive and behavioral impairment

causing: seizures, mental retardation, chronic behavior dysfunction, anemia**, renal toxicity, recurrent vomiting and abdominal pain.

Lead poisoning monitoring in children

5-44 ug/dL: - f/u blood lead monitoring - check iron status - +/- Hb or Hct - environmental investigation - lead hazard reduction - neurodevelopmental monitoring - abdominal x-ray with bowel decontamination (if indicated) 45-69: -f/u blood lead monitoring - check iron status - Hb or Hct - free erythrocyte protoporphyrin - environmental investigation - lead hazard reduction - neurodevelopmental monitoring - abdominal x-ray with bowel decontamination (if indicated) - oral chelation therapy - +/- hospitalization >=70: - hospitalize - oral chelation: binds to iron to excrete it

what lead levels in adults does not require any action

adults: under 25 ug/dL requires no action children: greater than 5 is poisonous and requires action

What are symptoms of lead poisoning?

Lead exposure = microcytic anemia* -> hypoxemia - fatigue, lethargy - lowered IQ: Mental retardation /developmental delays - renal toxicity - difficulty concentrating - hearing impairment - muscle/joint pain - abdominal pain/constipation - vomiting - encephalopathy: seizures - lead line (blue -black line) in gingival gums high exposure

What is pediatric and pregnant screening for lead based on

Risk or exposure - do not screen for lead poisoning if asymptomatic - only screen if you are exposed: paint, certain areas

Testing for illicit drugs, addictive and harmful therapeutic agents goal is to

*Detect past exposure by detecting metabolites (urine = recent usage) - hair + nails can show older usage Can test: - Urine - Serum - Meconium: stool in fetus that forms during 3rd trimester - breath - saliva - hair - nails

peripheral blood smear: lead poisoning

basophillic stippling of red cells

Detection Window for Commonly Abused Substances Urine Drug of Abuse Testing DAT: Amphetamines, Barbiturates, Benzodiazepines, Cocaine

-Amphetamines 2–4 days -Barbiturates 1 to >5 days- Depends on barbiturate -Benzodiazepines 2 to >8 days- Depends on benzodiazepine -Cocaine metabolite 2 to >7 days- Heavy users may remain positive for 6–10 days using sensitive immunoassays with a 150 ng/mL cutoff ----- -Methadone 1–4 days -Opiates 2 to >5 days- Heavy users may remain positive for up to 7–8 days -Phencyclidine 7–14 -THC (marijuana) 20–30

Detection Window for Commonly Abused Substances Urine Drug of Abuse Testing DAT: Methadone, opiates, PCP, THC

-Methadone 1–4 days -Opiates 2 to >5 days- Heavy users may remain positive for up to 7–8 days -Phencyclidine 7–14 -THC (marijuana) 20–30 --- -Amphetamines 2–4 days -Barbiturates 1 to >5 days- Depends on barbiturate -Benzodiazepines 2 to >8 days- Depends on benzodiazepine -Cocaine metabolite 2 to >7 days- Heavy users may remain positive for 6–10 days using sensitive immunoassays with a 150 ng/mL cutoff