ORGANIC ACIDS BY DR BASHIR AHMAD SIDDIQUI MBBS

ORGANIC ACIDS BY DR. BASHIR AHMAD SIDDIQUI MBBS, DMJ

ORGANIC ACIDS They have both local as well as remote (systemic) actions These are (1) Oxalic acid (2) Carbolic acid (3) Salycylic acid (4) Acetic acid

OXALIC ACID Physical properties It is a crystalline substance Sour in taste Acidic in reaction Sublimate on heating Effervescence with sod. carbonate Bleaches ink stains

ACTION It acts Locally as weak corrosive Remotely after absorption affects CNS, cardiovascular, electrolyte & renal system.

Symptoms & signs (A) Local Corrodes the mucous membrane of the GIT but rarely the skin. (B) Remote(systemic) 1 -In large doses & rapid death. Persistent vomiting (coffee ground in color). Pulse weak & skin cold & clammy. CNS depression & rapid death.

2 - When death in a few hours Pain, & tenderness over the abdomen Purging as well as tenesmus. Numbness, muscles twitching, convulsions, collapse & death. 3 - When death in a few days Nephrotoxic effects, oliguria, oxaluria(presence of calcium oxalate crystals in the urine), & uremia. Intestinal inflammatory changes.

Fatal dose- 15 -20 gms Fatal period- Mostly within an hour Treatment Gastric lavage with lime water. Antidotes-Any calcium preparation as chalk, cal. gluconate(IV), and cal. lactate. Symptomatic measures.

Christison’s saying (symptoms/signs) It spell out effects of oxalic acid. “if a person after swallowing a solution of a crystalline salt, which tasted strongly acidic, immediately suffers from vomits, especially of bloody matters. Further, his pulse becomes imperceptible and he dies in ten, twenty or thirty minutes. No disease begins so abruptly nor ends so soon and no other crystalline poison has the same effects. ”

Postmortem findings External Corrosion & staining of the face and skin rarely seen. Internal Mucosa of the mouth, tongue, pharynx, esophagus are bleached. Stomach changes The stomach mucosa is corroded Wall of the stomach is softened but perforation is rare.

Contents-dark brown (due to hematin). In rapid death. All viscera congested. No local changes in intestines. In delayad death. Inflammatory changes in GIT & kidney.

Commercial uses Oxalic acid is used. As bleaching agent. In calico printing. For removal ink stains.

Medicolegal importance Accidental poisoning- usually. Suicidal or homicidal- rarely. As an abortificient rarely. Used for illegal erasure of signatures.