Drug Toxicities notes

Question 1

What are examples of opioid drugs?

Answer 1

• Heroin (ingested, injected, smoked)
• Fentanyl (ingested or injected; used medicinally)
• Codeine (tylenol #3)
• Hydrocodone (vicodin)
• Meperidine (Demerol) – not used that much today
• Oxycodone (Percocet)
• Propoxyphene (darvocet) – withdrawn from US market Nov 2010
• Methadone

Question 2

What are the sxs of opioid OD?

Answer 2

Altered mental status, Decreased RR, Pinpoint pupils, Decreased bowel sounds, May also have dec heart rate, bp, temp

Question 3

What are the sxs of opioid withdrawal?

Answer 3

Agitation
    Anxiety
    Muscle aches
    Increased tearing
    Insomnia
    Runny nose
    Sweating
    Yawning
    Abdominal cramping
    Diarrhea
    Dilated pupils
    Goose bumps
    Nausea
    Vomiting

Question 4

How is opioid OD treated?

Answer 4

•	ABC’s (airway, breathing, circulation)
•	IV fluids
•	Oxygen 100%
•	Dextrose/thiamine
•	Opioid antagonists
A. Nalaxone

Question 5

What are the characteristics of Naloxone?

Answer 5

• Rapidly reverses coma and resp depression of opiod OD
• Works within 30 secs when given IV; half life 60-100 mins
• Can precipitate withdrawal in opiod abusers
• N/V/D, piloerection, yawning, irritability, normal mental status
• Lasts 15-30 minutes

Question 6

What are examples of benzos?

Answer 6

Diazepam (valium), Lorazepam (ativan), Flunitrazepam (Rohypnol)

Question 7

What are the sxs of benzo OD?

Answer 7

Depressed mental state, Normal vitals

Question 8

What are the sxs of benzo withdrawal?

Answer 8

anxiety, mood swings, depersonalization, poor concentration, social isolation, low energy, disturbed sleep

Question 9

What is the tx for benzo OD?

Answer 9

• ABC’s
• Supportive care
• Dextrose/thiamine
• Flumazenil

Question 10

What are the characteristics of flumazenil?

Answer 10

o Competitive benzo receptor antagonist
o Can ppt acute withdrawal
o Can ppt seizures as well as autonomic instability

Question 11

What are the the stages and sxs of acetaminophen OD?

Answer 11

•	Stage 1 (0.5-24 hrs)
o	Asymptomatic, mild irritation
•	Stage 2 (24-72 hrs)
o	LFT and renal fxn abnormalities +/- RUQ pain
•	Stage 3 (72-96 hrs)
o	Hepatic necrosis +/- renal failure
•	Stage 4 (4 days – 2 weeks)
•	Resolution of organ fxn

Question 12

How is APAP OD treated?

Answer 12

• Antidote = N-acetylcysteine (mucomyst)
• Best if given within 8 hrs of OD
• Effective for all stages of poisoning

Question 13

What are the poor prognostic sxs of APAP hepatotoxicity?

Answer 13

• PT > 100 secs
• Serum Cr > 3.3 mg/dl
• Hepatic encephalopathy (grade III-IV)
• Blood pH < 7.30

Question 14

What are the TCAs?

Answer 14

• Amitriptyline (elavil), Clomipramine (anafranil), Doxepin (sinequan), Desipramine (norpramin) Nortriptyline (pamelor)

Question 15

What are the sxs of TCA OD?

Answer 15

• Anticholinergic sxs including blurred vision, xerostomia (dry mouth), constipation, urinary retention
• Increased catecholamine activity → cardiac stimulation
• Blocking alpha adrenergic receptors → orthostatic hypotension and reflex tachycardia
• GABA antagonist → seizures
• Can block Na channels → widened QRS can lead to dysrhythmias

Question 16

What is the treatment for the Na channel blockade in TCA OD?

Answer 16

• Sodium Bicarb for Na channel blockade

Question 17

What is NaHCO3 used for in TCA OD?

Answer 17

alkalinizes plasma to reduce TCA binding to receptors in myocytes

Question 18

What are the anticholinergic drugs?

Answer 18

• Atropine, Diphenhydramine (Benadryl), Scopolamine (transderm scop), Meclizine (antivert)

Question 19

What are the sxs of anticholinergic OD?

Answer 19

• Altered mental status: confusion, hallucinations, seizures
• Elevated BP & temp, tachycardia
• Mydriasis (Dilated pupils, sluggishly responsive)
• Dry mucus membranes
• Decreased BS
• Dry flushed skin
• Urinary retention

Question 20

What is the treatment for anticholinergic OD including the anticholinergic sxs of TCA OD?

Answer 20

• Physostigmine – potentiates cholinergic activity throughout body by blocking destruction of acetylcholine, promoting increased stimulation of AcH receptors

Question 21

What are the cholinergic meds?

Answer 21

• Anticholinesterases

o Nerve gas, organophosphates, physostigmine

Question 22

What are the sxs of cholinergic OD?

Answer 22

• Opposite of anticholinergic sxs

o Miosis, salivation, lacrimation, urination, defecation, CNS excitation, brochospasm

Question 23

What is the tx for cholinergic OD?

Answer 23

• Atropine
o Dose to effect; very high doses may be needed
• Pralidoxime
o Enzyme regenerator (reactivates cholinesterase); decreases atropine requirement