Posted: August 11th, 2024

Iron Poisoning Pharmacology Case Study

Iron Poisoning Pharmacology Case Study
History: A 13-year-old female who is 37 weeks pregnant presents to your
emergency department via EMS after ingesting 70 prenatal iron tablets
two hours ago in a suicide attempt. EMS reports arriving at the scene
approximately one hour after ingestion and administering ipecac. The
tablets contained 325 mg of ferrous sulfate. The patient complains of
three episodes of emesis and diarrhea.
PMH: None.
Physical Examination:
T: 98.6°F HR: 110 bpm RR: 12 breaths per minute BP: 100/65 mm Hg
Weight: 65 kg
General: Alert female in no distress
HEENT: Mucus membranes moist. Pupils equal.
Pulmonary: Clear to auscultation.
CV: Tachycardic with regular rhythm and no murmurs.
Abdomen: Soft, mildly tender in epigastrium.
Rectal: Heme negative.
Neurologic: Normal.

Case Study questions
1. Did this patient take a toxic dose of iron?
2. Do you agree with the decision to administer ipecac? If not, is there a more
desirable way to perform gastrointestinal decontamination in this case?
3. What laboratory studies, if any, do you recommend?
4. Do you recommend chelation in this patient? If yes, how would you administer the
chelator and at what dose? If the urine does not change color, should treatment
be continued?
5. Is the fetus at high risk of becoming iron toxic?
6. What are the most common symptoms of iron poisoning?
7. Is iron detected on a routine toxic screen?
8. If an iron level is unavailable, are there any other laboratory findings that suggest
an elevated iron level (>300)?

Toxicology Case Study: Iron Poisoning
1. Yes. For all poisonings of iron-containing vitamins, it is important to calculate
the amount of elemental iron ingested. Ferrous sulfate contains 20% elemental
iron, so this patient ingested 325 mg X 70 X 0.2 = 4550 mg. The total
amount/kg is 4550/65 = 70 mg/kg. Because the toxic dose is 40 mg/kg, this
patient has a potentially severe ingestion. Doses of 60-180 mg/kg have been
associated with death.
2. Generally, there is no role for ipecac syrup administration. This is reflected by the
position statement by the American Academy of Pediatrics on ipecac syrup. The
American Academy of Medical Toxicology does not recommend emergency
department administration of ipecac syrup but has no formal position on home
use, though it is also not routinely recommended. Further, because the most
sensitive indicator of iron poisoning is vomiting, ipecac administration may confuse
potentially useful physical exam findings. If this patient had not already vomited or
if iron tablets were seen in the stomach on x-ray, gastric lavage would have been
the initial decontamination procedure of choice. This technique can be employed
in patients who present early enough for this procedure to be initiated within one
hour of ingestion. If the patient remained symptomatic, if tablets were noted past
the pylorus, or if the patient presented past the one hour mark, whole bowel
irrigation should be performed.
3. Laboratory studies that should be obtained include a serum iron concentration,
electrolytes if the patient has had several episodes of vomiting and a complete
blood count if there is suspicion of any bleeding. The most valuable time to assess
serum iron concentration is four to six hours after ingestion. Total iron binding
capacity (TIBC) is useless! While theoretically useful, the TIBC in iron poisoning is
often unreliable, falsely elevated, and does not correlate with symptoms.
This patient’s serum iron concentration is 400 mcg/dL.
Na 137, K 3.4 C1 109, CO2 18, BUN 5, Cr 0.7 glucose 383
WBC 17.8 H/H 13.1/36.8 acetaminophen is <10, salicylate <5 mg/dL. 4. The most important indication for deferoxamine is symptoms of iron poisoning. Most patients become significantly symptomatic with levels over 300 mcg/dL. Patients with severe symptoms (shock, lethargy/coma), anion gap metabolic acidosis, peak SIC >500 mcg/dL, significant numbers of pills on plain films and
worsening clinical condition despite maximal therapy should receive deferoxamine
(DFO), the intravenous chelating agent used to treat iron poisoning.
Deferoxamine can be administered IV or IM. This medication works by complexing
with ferric (Fe3+) iron, creating the complex ferrioxamine, which is excreted in the
urine. Intravenous administration is generally safe if the rate is <5 mg/kg/hr; however in adults, if that rate is chosen, they will receive very large doses of deferoxamine in 24 hours (25.2 grams). The recommended daily dose should not exceed 6-10 grams, so one can give 6 gm/24 hours or 250 mg/hr, which is approximately 3.5 mg/kg/hr. Another option is to start with 15 mg/kg/hr if the patient is very ill and decrease the dose after 1-2 hours. Larger doses are often used to start because prolonged dosing of DFO can cause adverse effects such as ARDS. Free iron may be present without the formation of the classic “vin rose” urine color change. If the patient remains symptomatic with elevated iron levels, treatment should continue even if there is no urine color change after the first dose of DFO. 5. No, because the placenta has an active mechanism for iron to cross. It occurs by active endocytosis. So if the mother has high iron levels, it is rare for the fetus to develop elevated iron levels. DFO probably does not cross the placenta, so pregnant patients should be treated no differently than non-pregnant, except for use of serial x-rays. Fetal monitoring should also be performed in pregnant patients with iron poisoning. If the fetus is viable and the mother is very ill or if fetal distress is noted, early delivery should be considered. 6. Gastrointestinal (nausea, vomiting, diarrhea). Any child that presents with sudden onset of GI symptoms should be questioned about iron availability in the household. 7. No. 8. Serum glucose >150, WBC >15,000 and acidosis all suggest a serum iron
concentration greater than 300 mcg/dL. If an iron level is available and there are
no other indications, those laboratories do not need to be routinely obtained.

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Tags: Chelation Therapy, Healthcare Papers, Iron Poisoning, Toxicology Case Study