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SALICYLIC ACID. Made by Dr. Amna Rao Presented by Sobia Hussain Roll # 80. SALICYLIC ACID. An odorless, crystalline solid substance. Has a sweetish taste. Used externally for treatment of skin diseases. It has a remote action after absorption.
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SALICYLIC ACID Made by Dr. Amna Rao Presented by Sobia Hussain Roll # 80
SALICYLIC ACID • An odorless, crystalline solid substance. • Has a sweetish taste. • Used externally for treatment of skin diseases. • It has a remote action after absorption. • Causes marked irritation of gastric mucous membrane.
Important preparations: Sodium salicylate and methyl salicylate (oil of winter green) are important prepations of salicylic acid. Natural forms: Salicin and methyl salicylate are naturally occuring forms, found in leaves and bark of a number of plants (willow tree).
FATAL DOSE • Salicylic Acid: 70-80 grams. • Sodium Salicylate and Acetyl Salicylic Acid: 15-20 grams. • Methyl Salicylate: 10-20 ml.
FATAL PERIOD • Salicylic Acid: 4-7 days • Sodium Salicylate: 1-3 days • Methyl Salicylate: 12-24 hours.
CLINICAL FEATURES: • In Therapeutic Doses, aspirin is absorbed rapidly from small intestine and stomach walls. • In Overdose absorption may occur more slowly and plasma salicylate concentration may rise up to 24 hours. • Salicylates stimulate respiratory centers inmedulla & increase rate and depth of respiration. CO2 is eliminated from the lungs causing respiratory alkalosis.
Dehydration and hypokalaemia results due to excess sodium, potassium and water excreted in urine. • Metabolic Acidosis develops because of interference with lipid, protein, carbohydrate and amino acid metabolism by salicylate ions. • Primary toxic effect of salicylate overdose is hyperpyrexia, sweating, fluid loss, nausea and vomiting. • CNS: acidaemia, tremors, delirium, convulsions, stupor and coma; so called salicylate jag. • Renal Involvement: maybe shown by proteinuria, sodium and water retention and tubular necrosis. • Tinnitus: deafness and increased labyrinthine pressure occurs. Coma occurs in terminal stages.
Stomach wash. • Gastric lavage with sodium bicarbonate solution. • Activated charcoal suspension can be used. • Forced alkaline diuresis can be helpful in eliminating aspirin and other salicylates from the body. • Sodium Bicarbonate in the dose of 1-2 meq/kg can be given intravenously. • IV fluids to correct electrolyte imbalance. • Vitamin K can be given in case of severe hypoprothrombinaemia.
POSTMORTEM APPEARENCE: • These include evidence of: • Hemorrhagic gastritis • Subpleural and subpericardial hemorrhages • Pulmonary and cerebral edema • Renal irritation • Congestion of viscera
MEDICOLEGAL ASPECTS: • Accidental Poisoning common in children.In adults cause hypersensitivity reactions. • Suicidal poisoning uncommon. • In neotaes, infants and children salicylate intoxication may occur through placental transfer, breast milk or by application of teething gel to the gums. • United states studies have suggested an association between Reye syndrome and use ofsalicylates. Salicylates should not be used in children under 12 years indicated for Childhood Rheumatic Condition.
Aspirin Hypersensitivity: • Increase salicylate levels. • Fatal hypersensitivity reaction occurs within minutes of ingestion. • Causes vasomotor rhinitis, angioneurotic edema and utricaria. • Laryngeal edema results in death. • Treatment involves immediate administration of adrenaline (s/c) and corticosteroids.