MERCURY
Most poisonous salt of Hg is mercuric chloride (corrosive sublimate), occurs as colourless
masses of prismatic crystals.
Symptoms — Acrid metallic taste, hoarse voice, greyish white coating of tongue, blood- stained stool, circulatory collapse, necrosis of jaw, membranous colitis, proximal renal
tubular necrosis.
Fatal dose: 1 to 4 gm. Fatal period: 3 to 5 days. Treatment:
Gastric lavage with sodium formaldehyde sulphoxylate. BAL (BALMIER) is chelator of choice. Penicillamine. 10 gm of sulphoxylate in 100 – 200 cc of distilled water by slow i.v. injection is repeated after 4 – 6 hours acts as an antidote.
Chronic Poisoning:
The symptoms are salivation, a blue line on gum, sore mouth & throat, fine tremors of the tongue, hands, arms, anaemia. Shaking palsy is associated c Hg poisoning. Mercurial tremors are also called hatter's shakes or glass blower's shake. Mercurial erethism is seen in persons working with mercury in mirror manufacturing firms. Erethism is characterised by shyness, timidity, irritability, loss of confidence, mental depression, loss of memory & insomnia. Mercurialentis is a peculiar eye change due to brownish deposit of mercury through the cornea on the anterior lens capsule. It is bilateral and has no effect on visual acuity.
LEAD
Acute poisoning —The symptoms are metallic taste, dry throat, peripheral circulatory
collapse, paraesthesias, depression, coma and death.
Fatal dose—Lead acetate 20 gm; lead carbonate 4 gm. Fatal period—One to two days. Treatment:
The combination of BAL and calcium disodium versenate is effective.
Chronic poisoning (plumbism)—causes:
Inhalation of lead dust and fumes by makers of white lead, smelters, plumbers, glass- polishers. Chronic poisoning results from a daily intake of one to two mg. of lead.
Signs and Symptoms:
LAPEC : L -» Lead line; A -» Anemia; P -» Palsy, Pallor, Punctate basophilia, E -»
Encephalopathy; C —> Colic, consti¬pation.
Facial pallor—The facial pallor about the mouth is one of the earliest and most consistent sign. Anemia—In early stage polycythemia but later there is anaemia which is associated with punctuate basophilia, polychromasia, nucleated RBC, and an increase in mononuclear cells of microcytic hypochromic anaemia. Punctate basophilia or basophilic stippling means the presence of many dark-blue coloured pinhead sized spots in the cytoplasm of red blood cells due to toxic action of lead on porphyrin metabolism. Lead line—A stippled blue line, called Burtonian line, is seen on the gums in 50 to 70% of cases. A similar blue line is seen in cases of poisoning by mercury, copper, bismuth, iron and silver. Abdominal colic and constipation—later symptoms. Lead palsy—wrist drop, peripheral neuropathy, foot drop. Encephalopathy—Lead encephalopathy is most common in children. The symptoms are vomiting, headache, insomnia, visual disturbances, delirium, hallucinations, convulsions, coma and death. In adult, encephalopathy is rare. Menstrual irregularity—amenorrhoea,
dysmenofrhoea. Renal dysfunction. Sterility.
Diagnosis:
In poisoning, the concentration of lead in blood is usually between 0.1 to 0.6 mg. per 100 ml. X-ray evidence of increased radio-opaque bands of lines at the metaphyses of long
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bones is seen in children.
Treatment:
Most effective treatment of plumbism is calcium-disodium versenate. BAL Penicillamine. COPPER
Copper as a metal is not poisonous. Copper compounds are powerful inhibitors of enzymes.
Ptysalism is seen in copper poisoning.
Fatal dose—15 gm. Fatal period—1 to 3 days.
Treatment: (i) Stomach wash c solution of potassium ferrocyanide. (ii) N-penicillamine.
(iii) EDTA. (iv) BAL.
ORGANIC IRRITANT POISONS
RICINUS COMMUNIS
The castor plant (arandi) grows all over India. Seeds are smooth, flattened-oval, mottled, light and dark brown. Entire plant is poisonous, containing toxalbumen RICIN, a water- soluble glycoprotein and a powerful allergen (CBA). A toxalbumen or phytotoxin is a toxic protein, which resembles a bacterial toxin in action and causes agglutination of red cells
with some hemolysis and is antigenic.
Signs and Symptoms—Symptoms include salivation, bloody diarrhoea, impaired sight, delirium, convulsions, uremia and jaundice. The powder of seeds when applied to the eye
causes conjunctivitis.
Fatal dose—Ten seeds; ricin 6 mg.
Fatal period—Two to several days.
P.M. appearances—Ricin produces haemorrhagic inflamma¬tion of the G.I. tract.
CROTON TIGLIUM
Croton tiglium (Jamalgota or naepala) seeds contain toxalbumen CROTIN and CROTONOSIDE, a glycoside, which is not expressed with the oil. Seeds are oval, dark-brown
with longitudinal lines.
Signs and Symptoms —There is hot burning pain from mouth to stomach, salivation, vomiting, purging, vertigo, prostration, collapse and death.
Fatal dose — 4 seeds; 1.5 cc. of oil.
Fatal period — 6 hours to 3 days.
Treatment: Stomach wash, demulcent drink and symptomatic treatment.
ABRUS PRECATORIUS
It is also known as Jequirity or Indian liquorice (gunchi or, rati). The seeds are egg-shaped, bright scarlet colour with a large black spot at one end. The seeds contain an active principle abrin, a toxalbumen, which is similar to viperine snake venom. In seeds also present is abrine, an amino acid, haemoglutinin in the cotyledons, a lipolytic
enzyme, and abralin, a glycoside.
Signs and Symptoms:
After ingestion, symptoms include abdominal pain, diarrhoea, weakness, cold perspiration, trembling of the hands, weak rapid pulse and rectal bleeding. When an extract of seeds is injected under the skin of the animal, inflammation, oedema, oozing of hemorrhagic fluid from the site of puncture, necrosis. The animal drops down after 3 to 4 days. Tetanic
convulsions occur.
Fatal dose — 90 to 120 mg. by injection, 10 gm. orally. Fatal period — 3 to 5 days. Poisoning — The seeds are used for killing cattle, small sharp-pointed spikes on needles or 'suis' are prepared which are then dried in the sun.
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ERGOTErgot is the dried sclerotinum of the fungus Calviceps purpurea, which grows on cereals like rye, barley, wheat, oats etc. It contains alkaloids, ergotoxin, erqotamine. and ergometrine.
Signs and Symptoms:
In acute cases, there is nausea, vomiting, diarrhoea, giddiness, tightness in the chest, difficulty, in breathing, marked muscular weakness and exhaustion. There may be tingling and numbness in the hands and feet, paraesthesias, followed by twitchings or cramps in the muscles Bleeding from nose and other mucous surface is common.
Chronic poisoning:
There is tingling and numbness of the skin, vasomotor disturbances leading to dry gangrene of the fingers. There is a sensation of insects creeping under the skin (tactile hallucination). Fatal dose—One to two gm. Fatal period—One to several days. Poisoning: The consumption of bread made with contaminated rye is the chief cause of ergotism. Ergot is commonly used as an abortifacient.
SEMECARPUS ANACARDIUM
Marking nuts (bhilawa) are black, heart-shaped with rough projections at the base. Their pericarp contains an irritant juice which is brownish, oily and acrid but turns black on
exposure to air.
The active principles are semecarpol and bhilawanol.
Signs and Symptoms:
The lesion resembles a bruise. The juice, when applied externally causes irritation and a
painful blister, which contains acrid serum.
Fatal dose — 5 to 10 gm.
Fatal period — 12 to 24 hours.
CALOTROPIS
The juice is taken by mouth or introduced into uterus on an abortion stick for criminal abortion and as a cattle poison. Also used as arrow poison. To produce artificial bruise. The juice produces an acrid bitter taste, salivation, dilated pupils, tetanic convulsions, collapse
and death.
Treatment: Stomach wash, demulcents and symptomatic.
SNAKES
The Poisonous snakes may be divided into five families— 1. Cortalidae — Pit viper, Rattle snake, Bush master. 2. Viperidae (true viper) — Russel's viper, Saw-scaled viper.
3. Elapldae — Cobra and Krait
4. Hydrophidae — Sea snakes
5. Colubridae — Boom slangs, Bird snakes.
In India, out of 200 species of poisonous snakes, five are dangerously poisonous to man. — King cobra, cobra, common krait, Russell's viper and saw-scaled viper. The most common poisonous snake is Common krait. Rat-snake is a non-poisonous snake. Difference between Poisonous and Non-poisonous snakes
Poisonous Non-poisonous
1 Belly
scales Large and cover entire breadth. Middle scale hexagonal.
Small and do not cover entire breadth.
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2. Head scales 1. Small (vipers) 2. Large and(a) If there is a opening between eye and nostril (pit-viper)
(b) Third labial touches the eye and nasal shields (cobra)
(c) Central row of scales on back enlarged; under surface of the mouth has only 4 infralabials, the fourth being the largest (kraits)
Head scales large with the exceptions as mentioned under the poisonous snakes.
3. Fangs Hollow like hypodermic needles Short and solid.
4. Tail Compressed Not much compressed.
5. Habits Usually nocturnal , Not so.
6. Teeth Two long fangs Several small teeth. Snake venom:
1) The venom of the Indian cobra (Naja-Naja) contains a neurotoxin, a hemolysin, a cardiotoxin, a cholinesterase, phosphatidase.
2) Venom of pit viper contains hyaluronidase and proteolytic enzyme.
3) Venom of elapids {cobra, krait) are neurotoxic. Death occurs from respiratory paralysis. 4) The viperine venom is mainly hemolytic, causes intra-vascular hemolysis and depression of coagulation mechanism.
5) The sea snake venom is myotoxic.
Clinical manifestations—The most common manifestation following snake bite (poisonous or non-poisonous) is fright.
Cobra:
Local symptoms start within 6 to 8 minutes. The bitten area is tender with slight burning pain. The patient feels sleepy, slightly intoxicated, weakness of legs and is unable to stand or move. There may be extra-ocular muscle weakness, ptosis and strabismus. Coma sets in and finally the respiration stops with or without convulsions and the heart stops.
Krait:
There is no swelling and burning pain at the site of the bite. True viper (Russel viper):
When venom is injected, the spot develops severe pain, the swelling starts within 15 minutes. Tingling and numbness over the tongue and mouth or scalp and paraesthesia