II. Epidemiology
- Responsible for 300,000 deaths per year in Asia-Pacific Region
III. Pathophysiology
- Dipyridilium compound
- Paraquat is an inexpensive herbicide typically used outside the U.S. (although some pockets of rural U.S. use)
- Paraquat is typically dyed blue to prevent Accidental Ingestion
-
Poisoning typically occurs with intentional ingestion for Suicide
- Mortality 40-60% with ingestion of 15 ml (1 tbs, 0.5 oz) of 24% solution
- Results in multi-organ failure over the course of days
- Mechanism of systemic toxicity
- Cellular metabolism of Paraquat generates free radicals resulting in toxicity
- Inhibits NADP reduction to NADPH
- Mitochondrial toxicity
- Cell membrane dysfunction (lipid peroxidation)
-
Pharmacokinetics
- Peak serum level at 4 hours after ingestion
- Excretion renal
IV. Findings: Skin Contact (Corrosive) to Concentrated Paraquat Solutions
- Skin irritation
- Nail shedding
- Skin exposure rarely causes systemic effects
V. Findings: Systemic (Ingestion)
VI. Labs
-
Complete Blood Count
- High White Blood Cell Count is associated with poor prognosis
- Comprehensive Metabolic Panel
- Increased Serum Creatinine is associated with poor prognosis
- Plasma Paraquat Level
- Plasma Paraquat >2.64 mcg/ml at 3 hours is lethal in 100% of cases
VII. Management
- Intravenous crystalloid
- Activated Charcoal within 4 hours of ingestion
- Avoid excessive Supplemental Oxygen
- Start Hemoperfusion within 6 hours of ingestion
- Disposition
- All symptomatic Paraquat exposures are admitted to hospital
- Observe all asymptomatic Paraquat exposures for at least 6 hours
VIII. References
- Tomaszewski (2021) Crit Dec Emerg Med 35(5): 28
- Gawarammana (2011) Br J Clin Pharmacol 72(5): 745-57 +PMID:21615775 [PubMed]
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| Definition (MSH) | A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds. |
| Definition (CSP) | poisonous dipyridilium compound used as a contact herbicide. |
| Concepts | Hazardous or Poisonous Substance (T131) , Organic Chemical (T109) |
| MSH | D010269 |
| SnomedCT | 22065005 |
| LNC | LP16830-9, MTHU009385 |
| English | Methyl Viologen, Paraquat, Viologen, Methyl, 4,4'-Bipyridinium, 1,1'-dimethyl-, Paraquat [Chemical/Ingredient], paraquat, Paraquat (substance) |
| Swedish | Parakvat |
| Czech | paraquat |
| Finnish | Parakvatti |
| Russian | PARAKVAT, METILVIOLOGEN, МЕТИЛВИОЛОГЕН, ПАРАКВАТ |
| Japanese | パラコート, メチルビオロゲン |
| Italian | Metil viologeno, Paraquat |
| Polish | Parakwat, Gramoxone |
| Spanish | paraquat (sustancia), paraquat, Paraquat, Metil Viológeno |
| French | Paraquat |
| German | Methylviologen, Paraquat |
| Portuguese | Metil Viologênio, Paraquat |
Ontology: Paraquat toxicity (C0413070)
| Concepts | Injury or Poisoning (T037) |
| SnomedCT | 75017004 |
| English | Paraquat toxicity, Paraquat causing toxic effect, Paraquat toxicity (disorder) |
| Spanish | intoxicación por paraquat (trastorno), intoxicación por paraquat, toxicidad del paraquat |
Ontology: Paraquat lung (C2931434)
| Concepts | Disease or Syndrome (T047) |
| MSH | C537171 |
| English | Paraquat lung, Paraquat induced lung disease |
