Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
92 Cards in this Set
- Front
- Back
|
Anticonvulsant overview
|
ABC's due to primary CNS depression
Dextrose, O2, Naloxone, Thiamine AMI? Also check, Bleed/Inf Intentional OD? urine drug screen, APAP level, pregnancy, and ethanol |
|
|
What OD ACs get levels checked?
|
PHY, CBZ, VPA, PB
|
|
|
PHY normal level?
when do peaks occur? |
normal is 10-20 mcg/mL
IR peaks 1.5-3hour ER peaks within 12h Peak may be delayed 24-38h in OD... Get serial levels! |
|
|
PHY ADME
Formula??? (exam) |
90% protein bound, so no dialysis
malnourished increases free levels correct = measured/[(0.2xalbumin)+0.1] normal alb level 3.5-5 |
|
|
Formula to correct for impaired renal function of PHY?
What CrCl requires this level? |
crrct PHY = measured/[(0.1xalbumin)+0.1]
req'd for <20ml/min |
|
|
What kinetics is PHY?
|
MM kinetics so in an OD situation the half-life roughly doubles
|
|
|
PHY with levels of...
>20? >30? >40? >50? |
>20 - nystagmus
>30 - ataxia, slurred speech >40 - mental status changes >50 - Coma; seizures |
|
|
ON EXAM...
The only form of PHY that cause Cardiotoxic and how? |
IV PHY causes dysrhythmias and hypotension with rapid admin. Due to propylene glycol solvent.
|
|
|
CBZ...
Therapeutic levels time frames Properties of note |
therapy from 4-12mcg/mL... lower if on other drugs
Peak: suspension 1.5h, IR 6h, ER 12h delayed in OD setting... bezoar Anticholinergic. |
|
|
Does MDAC benefit CBZ or PHY?
|
MDAC benefits CBZ only!
|
|
|
CBZ levels of...
>12? >30? >40? |
>12 increased incidence of nystagmus
>30 CNS depression >40 coma, seizures, cardiotox tx seizures w/benzo! |
|
|
other CBZ AE
Chronic? |
dystonia use benadryl, Choreoathetosis
Chronic causes hyponatremia due to release of vasopressin |
|
|
CV effects of CBZ may include
|
hypo, tachy, conduction abnormal, QT prolonger!! acute or chronic tox
|
|
|
When to admin AC with CBZ
|
due to anticholinergic effects, consider AC later. maybe up to 4 hours post ingestion?
|
|
|
CBZ hemodialyze? seizures? Dystonias?
|
no hemodialyze
seizure? use benzo dystonia? use diphenhydramine |
|
|
CBZ causes QRS widening. What to admin?
|
consider NaHCO3
|
|
|
VPA
Therapy level? % abs? peaks? bound? |
50-100mcg/mL
100% oral abs IR 1-4h; ER 4-5h for peak, up to 24h in OD setting 90% protein bound - can dec in OD; consider dialyze |
|
|
VPA and carnitine?
|
VPA OD depletes carnitine
results in hyperNH3 and liver tox decrease carnitine increase NH3 |
|
|
Toxic effects of VPA
|
initially CNS depression
large dose causes resp. depression major AE at levels >450mcg/mL |
|
|
hyperNH3 can be acute or chronic OD
What happens 3-5d after acute OD of VPA? |
VPA can cause metabolic acidosis
BMS can occur; leuko/thrombocytopenia anemia |
|
|
other VPA AE
|
liver failure, pancreatitis, renal failure
|
|
|
Most frequent tx of VPA OD?
|
supportive care ABCs
be prepared to intubate as with other anticonvulsants consider AC if not aspiration risk WBI if large ingestion of EC tablets |
|
|
Which AC consider MDAC?
|
rarely used
only considered for CBZ and VPA |
|
|
Only AC drug and OD needing hemodialyze?
|
VPA because huge OD can dec protein binding
|
|
|
When to consider carnitine supplements?
|
with VPA OD and hyperammonemia
carnitine will decrease NH3 |
|
|
VPA OD with what 3 indications point to use of carnitine?
|
hepatox
elevated NH3 serum OD USE carnitor! |
|
|
Gabapentin OD
|
CNS depression, typically benign
|
|
|
Felbamate OD
acute vs. chronic |
CNS depression, tachy, N/V
Chronic toxicity: anemia, liver fail |
|
|
Lamotrigene OD
|
Seizures, dysrhythmias,
QRS widening? consider NaHCO3 if >100msec |
|
|
Vigabatrin
|
delirium and agitation can be treated with a benzo.
|
|
|
Zonisamide
|
Resp depression, hypotension, brady
tx with fluids and atropine be prepped to intubate |
|
|
Topiramate
|
Metabolic acidosis and seizures
benzos for seizures prep to intubate |
|
|
Tiagabine
BP? HR? |
CNS depression, possible seizures
HTN tx with nitroprusside if severe esmolol if severe tachy |
|
|
OXC
BP HR Electrolyte? |
Hypo, brady, hyponatremia
|
|
|
APAP ADME
|
10-30% protein bound (low)
0.75-1 L/kg 95% is eliminated normal t1/2 2-3h |
|
|
What is the toxic metabolite?
|
NAPQI is produced when metabolized from 2E1! inducible by chronic EtOH
NAPQI is product of all cyps 2E1 is inhibited in presence of acute alcohol |
|
|
Glutathiones role in acute tox
|
reacts without an enzyme
removal of highly reactive groups liver exports it to plasma 20 enzymes are GSH dependent |
|
|
APAP toxic to...
liver kidney other tissues |
liver-NAPQI tox is not countered by GSH in liver
Kidney-may result in proximal tubular necrosis!!; renal 2E1, other tissue tox is related to these 2 |
|
|
Stage 1 APAP OD
|
asymptomatic, n/v, lethargy, sweating
0-24h |
|
|
Stage 2 APAP OD
|
asymptomatic, mild alt inc, upper right quadrant pain
24-48h |
|
|
Stage 3 APAP OD
|
72-96hours
huge increases in ALT/AST hepatic failure, enceph, coma, brain gets no glucose from liver! hemorrhage due to no clotting factors jaundice! |
|
|
Stage 4 APAP OD (if surived #3)
|
liver will regenerate over time
near normal labs within 1 week may last months |
|
|
Refer to ER for APAP OD if...
|
adult ingest >10g
Ped ingest >200mg/kg all attempted suicides |
|
|
Gastric Decontamination w/APAP OD
|
AC effectively abs APAP
best when given within 1-2hours AC also absorbs NAC DO NOT delay NAC to give AC |
|
|
Role of lavage or emesis for APAP OD?
|
Nope
|
|
|
! therapy levels of APAP
|
>_10mcg/mL is analgesia
4-18mcg/mL is antipyretic hepatotox >_150mcg/mL WHEN measured 4 hours after dose |
|
|
When to use the nomogram?
|
Rumack-Matthew Nomogram only for single acute dose w/in 4-24hours
above line? toxic dose ONLY from 4-24 hours! even useful for ER APAP forms |
|
|
What is NAC?
effects? |
N-actylcysteine
source of cysteine for GSH directly conj. of NAPQI source of SO4 for conjugation Anti-inflam rad scavenger |
|
|
When to give NAC?
|
Give NAC when above the toxic line of the nomogram.
Best results if started w/in 8h give regardless |
|
|
NAC dosing!!!
LD MD dilution |
LD 140mg/kg
MD 70mg/kg q 4 h for 72 hours!! NAC should be 5% final solution dilute w/juice due to rotten egg taste minimum 3 days at hospital |
|
|
Shortened NAC?
|
LD and 5 MD (20 hour course)
only for less severe cases |
|
|
IV NAC dosing!
LD MD |
LD 150mg/kg in 200ml D5W, given over 1 hour
1st MD 50mg/kg in 500ml D5W over 4 h 2nd MD 100mg/kg 1L of D5W over 16h |
|
|
Concern w/IV NAC in children?
|
Severe hyponatremia due to excess free H2O
Caution if child less than 40kg |
|
|
Labs to check with APAP OD
|
AST/ALT peak at 3-4days
serum bili PT time Scr and BUN electrolytes glucose APAP levels unnecessary after NAC started? |
|
|
APAP ER OD?
when to give NAC? |
if APAP below probable tox line but above 10mcg/mL, then start NAC and get APAP levels at 8 and 12 hours
Extend NAC is APAP is detectable after 72h of dosing |
|
|
Chronic APAP OD dosing
Use nomogram in chronic doses? |
10-15mg/kg/dose NMT 5 dose/day
NAC is indicated if APAP dose exceeds 200mg/kg/day or 10g/24hour Nomogram is not used for Chronic Doses!!! |
|
|
NAC tx for chronic APAP OD
|
look at transaminases to determine extent of liver damage
IV NAC should be continued until AST/ALT <_2x normal |
|
|
Why monitor Na in Li OD decontamination?
|
hyponat causes increase reabs of Na and Li in kidney.
|
|
|
Li tox, acute v. chronic
|
acute - no cutaneous or endo problems; mostly seize or inc QT
Chronic - myocarditis and cutaneous ulcers; hypothyroidism |
|
|
oral tx of NMS?
|
5mg tid of bromocriptine, can increase to 20mg qid if needed
|
|
|
what 2 antidespressants are assoc. with seizures?
|
venlafaxine or bupropion
|
|
|
Consequences of uncoupling w/salicylate poisoning
|
initial resp alkalosis due to O2 use w/no energy created.
later evolves to profound met. acidosis will get elevated anion gap |
|
|
when to refer aspirin OD?
|
>_150mg/kg/dose or day?
|
|
|
when to use dialysis in aspirin OD?
|
>_100mg/dL... watch units!!
|
|
|
Why alkalizine urine in ASA OD?
|
100x more excreted at pH 7 vs. pH 5
goal urine is pH=7.54 may need cont. inf NaHCO3 |
|
|
toxic ingestion of APAP
|
>10g/day adult or 200mg/kg/day kid
|
|
|
Therapy levels of Dig
tox level? |
0.6-2 ng/mL
>6ng/mL lethal for 50% |
|
|
What to avoid in dig OD?
|
Do not use Ca2+ or kayexalate
these will create abnormalities later |
|
|
Ind for digibind (doses of dig)
|
ingestion of...
>10mg if adult >4mg if child |
|
|
exam! formula for digibind admin
|
(conc@SS + wt in kg)/100
= number of vials to admin |
|
|
When are fab frags given in infants and children? (dig/wt dose)
|
>_0.3mg/kg!!
|
|
|
What to do about brady in clonidine OD?
|
give atropine if HR<60bpm, consider pacing if refractory
|
|
|
Diff b/w BB and CCB OD?
|
BB - hypogly, bronchospz, CNS effects
CCB - hypergly, pulmonary edema, more cardiac effects |
|
|
Similarity b/w BB and CCB OD?
|
both cause hypotension and bradycardia
|
|
|
What special effect does sotalol have?
|
blockade of K channels
so potential for torsades |
|
|
tx of CCB and BB OD similarity
|
give atropine and IV fluids to combat hypotension and brady
also IV Ca2+ is beneficial in both cases |
|
|
tx specific to BB OD
|
give glucagon because it bypasses need for cAMP for contraction
|
|
|
IV calcium role in CCB and BB OD
|
CaCl2 if good access,
otherwise use Cagluconate to reduce irritability Always give glucagon 1st if in BB OD! |
|
|
tx specific for CCB OD
|
give insulin and glucose to...
support metabolic heart demands increase energy and coronary flow to heart |
|
|
hyperinsulin euglycemia
|
0.5 - 1 IU/kg w/25g dextrose
titrate with 0.5-1IU/kg/hour dilute 1IU with 1 mL NS monitor glucose q 30min |
|
|
1st 5 of 10 toxic exposures in children
|
cosmetics
analgesics cleaning substance foreign body topical prep |
|
|
2nd 5 of 10 toxic exposures in kids
|
vitamins
cold/cough antihistamines pesticides plants |
|
|
drugs specific to tramadol OD
|
consider naloxone
admin lorazepam for seizures NS for hypotension |
|
|
Drugs specific to Li OD
which is more severe acute or chronic? |
Chronic OD is more severe.
|
|
|
Normal Li level?
mod symptoms severe symptoms |
normal 0.6-1.2mmol/L
mod: 1.5-2.5 mmol/L lethal: 3-4mmol/L |
|
|
What specific drug can be used to manage Li OD causing arrhythmia?
|
MgSO4 bolus
|
|
|
Jimson Weed OD... what not to use?
|
avoid phenothiazine and benadryl due to anticholinergic effects!
|
|
|
What's 1 drug of use in jimson weed OD?
|
MOA: Achinhibitor called physostigmine
|
|
|
TCA OD; QT prolonger when to be worried?
|
>100msec QT interval causes problems>100 -> 33% seized
>160? 50% had dysrhythmia |
|
|
Acute OD of TCA: symptoms
|
hot as a hare
dry as a bone mad as a hatter blind as a bat red as a beet |
|
|
TCA OD effect on myocardium
|
TCA block myocardial Na channels (fast) resulting in dec conduction and increased
|
|
|
vasopressors used in...
clonidine OD? TCA OD? |
clonidine use dopamine
TCA use NE |
