Thallium Toxicity - 2024 PDF

Thallium toxicity Presented by 1 ph/Algaly Aktham Torky  Introduction ▪ Thallium is a tasteless, odorless, and water-soluble heavy metal for which both accidental intoxication and criminal poisoning have been reported. Uses: 1. Insecticide and rodenticide. 2. Tr...

Thallium toxicity Presented by 1 ph/Algaly Aktham Torky  Introduction ▪ Thallium is a tasteless, odorless, and water-soluble heavy metal for which both accidental intoxication and criminal poisoning have been reported. Uses: 1. Insecticide and rodenticide. 2. Treatment of malaria and ringworm of the scalp( tinea corporis). 3. Used in the glass lens industries. 4. In Pharmaceutical cosmetic products, applied for facial hair removal. 2 patterns of spread: 1. Absorbed through the skin ( dermal contact) 2. Respiratory inhalation( used as insecticide and rodenticide) 3. Absorption through the gastrointestinal tract( ingestion) N.B: ▪ It can cross the placenta and cause harmful effects on the fetus. ▪ Deposition: hair and nails after a period of exposure. 3 Mechanisms Of Toxicity ▪ Thallium enters cells by a unique process governed by its similarity in charge and ionic radius to potassium. ▪ Thallium acts on cells and mitochondria by: 1. altering cell membrane permeability. 2. activating apoptosis. 3. inhibiting the electron transport chain reducing ATP synthesis. 4. inducing oxidative stress and generating ROS damaging DNA and proteins. 4 5 Mechanisms Of Toxicity 1. Thallium inhibit sodium/ potassium ATPase pump inhibiting glucose, amino acids and nutrients transport into cells by altering membrane permeability. 2. Thallium disrupts the balance between anti-apoptotic(Bcl-2) and pro-apoptotic(Bax) genes activating apoptosis. 3. Thallium inhibits ETC and makes uncoupling of oxidative phosphorylation ATP depletion. 4. Thallium reduce the amount of reduced glutathione GSH ( free radical scavenger) inducing oxidative stress , generating ROS and damaging DNA and proteins. 6 Manifestations ▪ Gastroenteritis ( GIT upsets) : sever nausea, vomiting and diarrhea after 3:4 hours of exposure. ▪ Painful and rapidly progressing peripheral neuropathy ( especially on the soles and palms): paresthesia, numbness, prickling or tingling sensation in the affected body part (Pins and needles) ▪ Hair loss that progresses to widespread alopecia as it causes atrophy of the hair follicles after 3:4 weeks of exposure ▪ Transverse white lines in nails(Mee’s lines) about one month after the poisoning. ▪ Skin rash, redness and scaling of the palms and soles. ▪ Cardiovascular symptoms ( hypotension, tachycardia). ▪ CNS effects ( dementia, convulsion). 7 8 9 Management of toxicity ▪ If possible, remove the source of exposure and contaminated clothing. ▪ Initial stabilization: assess ABC (airway, breathing, cardiovascular system). ▪ Provide oxygen if necessary ▪ Decontamination: if ingested in the last 30 minutes, gastric lavage ▪ Gastric decontamination with activated charcoal and Prussian blue(potassium ferric hexacyanoferrate) ??? Prussian blue has an adsorptive capacity higher than activated charcoal. ▪ With skin exposure, wash exposed skin with soap and water. ▪ For eye exposure, irrigate exposed eyes with enough room temperature water for at least 15 minutes. 10 Forced diuresis with potassium ???? ▪ Not advisable nowadays 11 12