Toxicology numbers Drug Toxic dose/level Antidote – indications

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Toxicology numbers
Drug
Toxic dose/level
Amisulpride
>4g needs monitoring, 48g → QT ↑ torsades risk,
8-15g → cardiotoxicity,
>15g → coma, torsades
Amphetamines
Single pill in non-tolerant
individuals.
Arsenic
<5g mild GI symptoms
>100-300 mg → lethal
<1mg/kg in children
lethal
Rapid onset rice-water
diarrhea, GI hemorrhage.
Encephalopathy,
seizures. Salivation with
garlic odour. Spot urinary
conc. >1000mcg/L
Propranolol and sotalol
most likely to cause
symptoms. <1g of
propranolol can cause
severe tox. Hypotension,
bradycardia, 1st to 3rd HB.
QRS widening with
propranolol. ↑QT with
sotalol. Delirium, coma,
seizures with Pr. d/t CNS
penetration.
Hypo/hyperglycemia
likely.
Sedation most common
occurrence, co-ingestions
(ETOH) most common
hazard. Apnea from resp.
obstruction.
β – blockers
Benzodiazepines
Calcium channel
blockers
Verapamil/ diltiazem.
>10tab in adult can cause
severe tox, >1tab in
Antidote –
indications/dose
NaHCO3,
hyperventilation,
Magnesium for torsades,
chemical/electrical
pacing. Charcoal up to 4
hours from ingestion if
large dose.
Intervention indicated for
HT, seizures,
hyperthermia,
hyponatremia (MDMA)
Phentolamine 1mg
IVq5min. IV BDZ for
agitation,
intubation/paralysis for
hyperthermia
Chelation with
dimercapol or succimer
Dimercapol 3mg/kg IM
q4h or succimer 10mg/kg
TDS
End-points
Atropine 0.01-0.03mg/kg
IV, Adrenaline,
Isoprenaline 4µg/min
infusion. Glucagon 510mg bolus +1-5mg/hr
infusion for bradycardia.
NaHCO3 1-2meq/kg
boluses for ↑QRS.
Magnesium/ overdrive
pacing for torsades. High
dose insulin euglycemia.
QRS<120ms, HR>60 or
hemodynamic stability
Flumazenil – for
accidental pediatric OD,
to confirm BDZ OD,
reversal of conscious
sedation in nondependent patients. 010.2mg IV boluses max
2mg. ½ life 90mins.
Infusion of 2/3rd last hour
requirement.
Early controlled
ventilation prior to circ.
collapse. Fluid boluses.
GCS >14, RR>12, w/f
seizures and BDZ
withdrawal symptoms.
0.01-0.02mg/kg pediatric
dosing.
Normal QT interval
β – blockers C/I
Chronic can be managed
as out- patient.
Asymptomatic for 4hrs
post standard prep and
>16hrs if SR prep.
children. Onset 2h for
standard up to 16hrs for
SR. bradycardia, 1st-3rd
HB, refractory shock.
Hyperglycemia, lactic
acidosis from ↓tissue
perfusion.
Carbamazepine
Carbon monoxide
Chloroquine
Clonidine
Colchicine
Predictable dosedependent
CNS/anticholinergic. 2050mg/kg mild-moderate,
>50mg/kg coma,
hypotension and
cardiotoxicity. 8-12mg/L
– therapeutic, >12
nystagmus, >20 CNS +AC,
>40 coma, seizures,
cardiac
>30% COHb, features –
LOC, coma, age>55,
seizures, cerebellar signs,
cardiovascular
compromise (ischemia),
severe metabolic acidosis
>20% COHb in children
and pregnant women
9fetus more susceptible
due to ↑binding to fetal
Hb.
>10mg/kg potentially
toxic. >30mg/kg ↑
mortality. >5g potentially
lethal. 1 tab in children
potentially lethal. Onset
<2hrs – dizziness, nausea,
vomiting, cardiac
conduction defects,
seizures, hypokalemia
Poor correlation with
dose. >20µg/kg
symptomatic. CNS↓,
miosis and bradycardia.
Children 1 tab lethal.
Symptoms always within
6h.
≥ 0.1mg/kg significant
mortality,>0.5mg/kg GIT
Calcium chloride 10%
20ml (0.2ml/kg) IV q15m.
infusion to maintain
>2.0meq/l (sometimes up
to 5). Atropine 0.010.02mg/kg bolus.
Ionotrope infusions.
NaHCO3 0.5-1meq/kg for
acidosis. Pacing if HR<60.
AC + WBI. High dose
insulin euglycemia.
IV NaHCO3 for cardiac
arrhythmias (rare). BDZ
for seizures. AC and
MDAC considered until
bowel sounds+ for
intubated patients. EC
elimination for severe
cases.
Hyperbaric oxygen –
single session for acute
effects, may need
multiple sessions for
delayed sequelae. <10% smoker, 10% slight
headache, 20% dizziness, nausea,
dyspnea, headache, 30%
- vertigo, ataxia, visual
disturbance, 40%
confusion, coma,
seizures, syncope, 50% CVS/RS failure,
arrhythmias, seizures,
death.
Intubation/ventilation for
coma, BDZ for seizures,
NaHCO3 for ↑QRS, K for
hypokalemia, high dose
diazepam IV infusion
considered.
Delayed absorption of SR
may cause days of
CNS/AC symptoms.
Levels in therapeutic
range for 48-72hrs may
need to be observed
after significant OD.
COHb <10%, correction
of acidosis and for
delayed sequelae –
improvement in
symptoms
All pregnant patients to
be considered.
Supportive care until
stable.
Naloxone 0.1mg IV q12min trial, if response
consider infusion
Stage 1 – GI symptoms,
leukocytosis
Supportive care, delayed
charcoal justified as even
symptoms, 0.5-0.8mg/kg
systemic toxicity + BM
tox. (10% mortality) ≥
0.8mg/kg CV collapse,
coagulopathy, ARF, fatal.
(100% mortality)
Cyanide
Digoxin – Acute
Digoxin – Chronic
Ethanol
Ethylene glycol
Nausea, HT, tachycardia,
agitation, collapse and
seizures → hypotension,
bradycardia, confusion,
tetany, resp. depression
and coma. Serum lactate
strongly correlates levels
- >10mmol/L cyanide
level >40µmol/L.
>20µmol/L –
symptomatic, >40 –
potentially toxic, >100 –
lethal. Profound lactic
acidosis due to
cytochrome dysfunction.
>10mg in adult >4mg in
child potentially toxic.
S.digoxin level >15nmol/L
at any time, S.K level
>5.5mmol/L.
Nausea, vomiting, abdo.
Pain, bradycardia, 1st-3rd
HB, slow AF,
↑automaticity –
bigeminy, SVT, VT,
hypotension.
Hyperkalemia early sign.
Levels alone poorly
correlate toxicity. Clinical
features and level
>1.5ng/ml. bradycardia,
GI symptoms,
automaticity and
combinations of each.
Symptoms similar to
acute except milder.
Visual – chromatopsia
and xanthopsia.
0.5g/kg – 0.05g/dl% →
euphoria
1g/kg – 0.1 % → slurred
speech, CNS depression
2g/kg – 0.2% → potential
for coma in non-tolerant
>5g/kg – >0.4% → coma,
resp. depression
>1ml/Kg → lethal
Deliberate self-poisoning
always consider lethal
Stage 2 – 48hrs – 7days –
BM suppression,
infection, DIC, ARF, ARDS,
MODS, neuropathy,
electrolyte abnormalities
Recovery – alopecia,
rebound leucocytosis
Decontaminate body
with soap and water.
Available antidotes –
hydroxycobalamin, Na
thiosulfate, dicobalt
edetate.
Hydroxycobalamin
administered with Na
THS separately. 5gm in
200ml 5%D over 30mins.
small amounts of
unabsorbed drug will
affect outcome. Utility of
G-CSF for leucopenia –
controversial.
In arrest 20vials of FAB
followed by at least
30mins CPR. Correct
hyperkalemia (no Ca).
atropine for bradycardia,
lignocaine IV 1mg/kg for
VT.
No of amps = ingested
dose (mg) x 0.8 x 2. Or if
unknown dose 5-10 amps
depending on severity
q30mins.
Treat hyperkalemia, VT
and AV block as above.
Definitive Rx D-FAB. No
of amps = serum digoxin
level x body wt / 100 or if
level not available give
2amps q30mins.
Effects of FAB evident in
20mins up to 4 hrs.
Restoration of normal
cardiac rhythm and
conduction. Resolution of
GIT symptoms.
None, no role for
enhanced elimination as
supportive therapy
usually enough.
No level suggestive,
clinical features mostly
used. Consider
counseling at discharge.
Hemodialysis –definitive
management. Osmolar
gap >10, acidemia <7.25,
Correction of acidosis,
osmolar gap <10, EG
<3.2mmol/L
Resolution of lactic
acidosis and
improvement of tissue
hypoxia.
As above.
Venous bicarbonate good
surrogate marker. ↑
lactate, hypocalcemia
and ↑ creatinine –
considered pathognomic.
Iron fumarate (33%),
chloride (28%), sulfate
(20%), chloride (28%)
and gluconate (12%)
>40mg/kg need
assessment, >60mg/kg
likely toxic. >90µmol/L at
4 hrs.
Methanol
>0.5ml/kg → lethal.
Deliberate self-poisoning
usually lethal.
Methemoglobinemia
>30% MHb indication for
IV methylene blue
<30% MHb indication for
oral MB, ascorbic
acid/riboflavin
ARF, ethylene glycol level
>8mmol/L
Ethanol therapy used
where hemodialysis
unavailable. 1.8ml/kg of
43% ETOH NG bolus, 0.20.4ml/kg NG infusion.
Goal 22-33mmol/L serum
level.
Desferroxamine
15mg/kg/hr if acidosis pH
<7.1, level 60-90µmol/L +
visible tablets on x-rays
or >90µmol/L at any time
Bicarbonate to maintain
pH>7.30 to prevent
formic acid damage.
Folinic acid therapy
2mg/kg IV QID
Hemodialysis treatment
of choice
pH <7.3, visual
symptoms, renal failure,
methanol >16mmol/L
Methylene blue (PO/IV)
Ascorbic acid, Riboflavin
Correction of acidosis,
complete
decontamination, AG
corrected, level
<54µmol/L. not
>80mg/kg/24hrs of
antidote. Rarely >24hrs
Correction of acidosis,
osmolar gap <10,
methanol level <6mmol/L
Ethanol therapy as above
W/f hemolysis with MB
use especially in patients
with G6PD deficiency
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