Formic acid poisoning can result from the accidental ingestion of formic acid or methanol oxidation. Formic acid is a colorless liquid with a pungent odor that is naturally produced by ants. Ingestion of formic acid can be deadly, with fatality occurring between 35-100% depending on the volume consumed. Formic acid poisoning works through several cellular mechanisms, preventing cellular respiration and producing metabolic acidosis. Symptoms range from initial vomiting and abdominal pain to later complications like shock, renal failure, and death. Treatment focuses on airway protection, fluid resuscitation, acidosis management, enhanced removal through folinic acid, furosemide, and possible hemodialysis. Severe metabolic acidosis

1. Formic Acid Poisoning

2. Formic Acid
• Produced as result of METHANOL
oxidation.
• Colourless liquid with purgent odor
• Naturally occurred in ant.
• Commonly available in market – use
for latex coagulation (buat
kentalan)
• Accidental ingestion can be deadly
(range 35 -100%) depend on
volume ingested
D.R. Lycke, S.L. Blair, in Encyclopedia of Electrochemical Power Sources, 2009

3. https://www.wikem.org/wiki/File:Toxic_alcohol_ingestion.JPG

4. Cellular Mechanism
• High formic acid concentration > saturate
tetrahydrofolate synthase> prevent further
conversion to water and carbon dioxide
• Formic acid bind with mitochondria (bind with
cytochrome C oxidase) > histotoxic hypoxia>
generate more acid (lactic acid) > hasten cellular
injury
• Formic acid > formate + H> metabolic acidosis
• Lactate produced by prevent cellular respiration
• pH reduced> formic acid less dissociate > enter
CNS > alter hemodynamic status, mental status

5. Formic Acid Ingestion
• Fatality dose: 15 ml – 200 ml
• Common presentation of ingestion:
– Initial presentation:
• vomiting
• Abdominal pain
• Esophageal burning sensation.
– Subsequent stage:
• GI perforation
• Renal failure
• Hematemesis
• Dark urine
• Respiratory
– Late Stage:
• Shock
• Transesophageal fistula
• Death

6. Management of Formic Acid Poisoning
• No specific Management, No specific antidote
• 1st:
– Secure airway
– Maintain hemodynamic stability – run fluid
• 2nd: Pharmacologic management
– PPI/ Sucralfate – secure Gastric line
– Metabolic acidosis – Sodium bicarbonate (not mention dose/ how to
administer)
– Steroid may reduce body stress but might worsen GI perforation
– Enhance removal:
• IV folinic acid 1 mg/kg bolus 4 hourly x 6 doses
• IV frusemide
• Hemodialysis
• Severe hemolysis: transfuse whole blood.
• Indication for hemodialysis:
– Severe intravascular coagulation with renal failure

7. • Indicator of high mortality rate: severe
metabolic acidosis, skin damage, severe acute
renal failure

8. References
• Nayanatara V et al. Case of formic acid poisoning: prompting for a different line of
management Int J Res Med Sci. 2019 Oct;7(10):3941-3944
• Ravishankar S Bhat. at el. Acute Formic Acid Poisoning: A Case Series Analysis with
Current Management Protocols and Review of Literature. Int J Head Neck Surg
2014;5(3):104-107.