Natural Poisons (Ackee, cassava, scorpion, snake, salmonella Flashcards
What toxic compound is in ackee?
Hypoglycin A. Rapidly diminishes in the open fruit due to the action of light
Describe the MOT of ackee
Hypoglycin A, a water soluble amino acid is metabolised to (MCPA-CoA). MCPA-CoA inactivates acyl-CoA dehydrogenase.This in turn inhibits beta-oxidation.
Explain the 5 action of ackee and the condition they lead to
(1)Inhibition of gluconeogenesis due to diminished concs. of NADH & acetyl CoA leads to
HYPOGLYCEMIA
(2) Accelerated catabolism of body proteins & inhibition of metabolic pathways normally catabolising AA. HYPERAMMONEMIA
(3) Interference with ATP production METABOLIC ACIDOSIS
(4) Depression of CNS function. LETHARGY & CONVULSIONS
(5) Stimulation of CTZ NAUSEA & VOMITING
Describe the management of ackee poisoning
Hypoglycaemia- Obtain a rapid finger stick glucose and initiate glucose replacement with D50W boluses and continuous infusion of 10% dextrose
Airway compromise
Fluid depletion- establish IV access
Seizures- benzos
GIT decontamination- charcoal and gastric lavage
Describe the MOT of bitter casava
Bitter cassava contains cyanide. Binding of CN- to cytochrome c oxidase in mitochondria. Stable but not irreversible binding. CN- has higher affinity for the Fe3+ in methemoglobin leading to interruption of oxidative phosphorylation
How does Cyanide from bitter cassava affect organs
- Carotid and aortic chemoreceptors
Intense stimulation from lack of usable oxygen
Results in neural stimulation of respiratory center - CNS
Variation of sensitivity and effects within CNS
Respiratory-center failure (central apnea):USUAL MECHANISM OF DEATH
3.Heart
Increased demand (from released catecholamines)in the face of reduced energy supply
Cardiac dysrhythmias and heart failure
Explain the effects of the MOT of cn
No generation of ATP;cessation of all processesdependent upon ATP
No extraction of O2 from blood;decreased AV O2 difference
Pasteur shift to anaerobic glycolysis;lactic acidosis and high anion gap
Describe general supportive therapy of Bitter cassava - cyanide
- Termination of exposure
- Airway, Breathing, and Circulation
- 100% oxygen (normobaric vs. hyperbaric)
- Correction of metabolic acidosis
- Observation for at least 24 to 48 hours
What is the antidote of Bitter cassava - cyanide
- Administration of a sulfane (e.g., sodium thiosulfate) as a sulfur donor for the enzymatic conversion of CN- to thiocyanate
- Displacement of CN- from cytochrome c oxidase
Reaction of CN- with metHb generated by nitrites or other metHb formers
Rattle snakes belong to which family
Viperidae
Viperidae produces what kind of venoms
Viperidae produces hemolytic venoms
How are rattle snakes bites managed
use tourniquets (not for prolonged use)
Incisions are not helpful
Avoid cooling measures and ice application
the only proven therapy for Rattle snake - management
Antivenom is the only proven therapy
Should be started as soon as possible if evidence of systemic envenoming is present.
Administer according to manufacturer’s instructions.
The venom of scorpions is composed of varying concentrations of:
Neurotoxin
Cardiotoxin
Nephrotoxin
Hemolytic toxin
The most potent is the venoms is the neurotoxin, why?
Causes cell impairment in nerves, muscles, and the heart by altering ion channel permeability.
The long-chain polypeptide neurotoxin causes stabilization of voltage-dependent sodium channels in the open position. The short polypeptide neurotoxin blocks the potassium channels
The toxicity, variation and duration of the symptoms of scorpions depends on the following factors:
Scorpion species
Scorpion age, size and nutritional status
Quantity of venom
Age of the victim
Heath of victim
describe grades of scorpion stings
I. Local pain at site of envenomation
II. Pain remote from the site of the sting and/or tachycardia
III. Cranial nerve or somatic skeletal neuromuscular dysfunction:
Cranial nerve dysfunction: blurred vision, wandering eye movement
Somatic skeletal neuromuscular dysfunction: jerking extremity.
IV. Any combination of cranial nerve dysfunction, somatic skeletal neuromuscular dysfunction.
Describe treatment of scorpion bites
Analgesic, antivenom, GTN, benzos,
Two main kind of salonellosis
Two main kinds in humans: enteric fever (typhoid and paratyphoid) and gastroenteritis
Describe the MOT of salmonella
Colonization of lower intestines and mucosal invasion. This results in the release effector proteins.
This is manifested by increased permeability and decreased tone of the vessels, leading to fluid production and diarrhea
describe Salmonella - treatment
Salmonellainfections usually resolve in 5-7 days and often do not require treatment other than oral fluids/electrolyte replacement.
Persons with severe diarrhea may require rehydration with intravenous fluids. Antibiotics, such as ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin, are not usually necessary unless the infection spreads from the intestines.
How can salmonella be prevented
vaccines, education, bottled water, safe cooking practices
