Studiul in toxicatiilor acute:
Etiologie
- &nb 616k1012g sp; &nb 616k1012g sp; Substante chimice → foarte diverse
- &nb 616k1012g sp; &nb 616k1012g sp; Medicamentoase
- &nb 616k1012g sp; &nb 616k1012g sp; Nemedicamentoase
- &nb 616k1012g sp; &nb 616k1012g sp; Intoxicatiile acute → au caracter violent, pun viata in pericol
- &nb 616k1012g sp; &nb 616k1012g sp; Toate substantele sunt toxice - nu exista nici una care sa nu fie toxica → numai doza difera un toxic de un medicament (remediu)
Compusi implicati:
- &nb 616k1012g sp; &nb 616k1012g sp; alcool etilic, diazepam, morfinice, fenciclidina, marijuana, amitriptilina, aspirina, plante, hidantoine, hipnotice, amfetamine
Evaluare - punct de vedere diagnostic
- &nb 616k1012g sp; &nb 616k1012g sp; dependent de droguri de abuz
- &nb 616k1012g sp; &nb 616k1012g sp; intoxicatie cronica
- &nb 616k1012g sp; &nb 616k1012g sp; cu supradozare - intoxicatie acuta
- &nb 616k1012g sp; &nb 616k1012g sp; sindrom de intrerupere
- &nb 616k1012g sp; &nb 616k1012g sp; Toxicitate
- &nb 616k1012g sp; &nb 616k1012g sp; Cantitativa → cantitatea ce produce moartea
- &nb 616k1012g sp; &nb 616k1012g sp; Calitativa → mecanism de producere, mecanismul efectelor toxice
DL 50 → mg/kg, mmoli/kg (pentru exactitate), mg/m2 → folosita mai ales la copii (pe suprafata corporala)
DML la om - doza minima letala
- &nb 616k1012g sp; &nb 616k1012g sp; se determina prin extrapolare
- &nb 616k1012g sp; &nb 616k1012g sp; din experienta chimica (nicotina =50 mg)
CL 50 = concentratie letala 50
CLt 50 = cat timp inhalezi pentru a ajunge sa preiei din atmosfera concentratia letala
Ppm = parti per milion sau g/m3
- &nb 616k1012g sp; &nb 616k1012g sp; e grosolana pentru ca nu da alte informatii despre mecanism
Toxicitate |
DL 50 |
Supertoxice |
5 mg/kg |
Extrem de toxice |
5 - 50 mg/kg |
Foarte toxice |
50 - 500 mg/kg |
Moderat toxice |
0,5 - 5 g/kg |
Cu toxicitate redusa |
5 - 15 g/kg |
Practic netoxice |
> 15 g/kg |
- &nb 616k1012g sp; &nb 616k1012g sp; orala 72,2 %
- &nb 616k1012g sp; &nb 616k1012g sp; inhalatorie 5,1 %
- &nb 616k1012g sp; &nb 616k1012g sp; oftalmic 5,3 %
- &nb 616k1012g sp; &nb 616k1012g sp; cutanata 6,3 %
- &nb 616k1012g sp; &nb 616k1012g sp; mai rar prin lezare (efractie) tisulara
- &nb 616k1012g sp; &nb 616k1012g sp; erori
- &nb 616k1012g sp; &nb 616k1012g sp; acte criminale
- &nb 616k1012g sp; &nb 616k1012g sp; incercari de suicid
Absortia
Transportul
- &nb 616k1012g sp; &nb 616k1012g sp; prin membrane biologice
- &nb 616k1012g sp; &nb 616k1012g sp; la nivelul sangelui
Distributie
Metabolism
- &nb 616k1012g sp; &nb 616k1012g sp; Substante
- &nb 616k1012g sp; &nb 616k1012g sp; hidrosolubile → nu se metabolizeaza de obicei
- &nb 616k1012g sp; &nb 616k1012g sp; liposolubile → se metabolizeaza
Toxicitatea unor substante este consecinta metabolizarii lor
Entitatile toxice sunt consecinta metaboizarii unor compusi:
- &nb 616k1012g sp; &nb 616k1012g sp; epoxizi
- &nb 616k1012g sp; &nb 616k1012g sp; radicali liberi
- &nb 616k1012g sp; &nb 616k1012g sp; compusi N hidroxilati
- &nb 616k1012g sp; &nb 616k1012g sp; nitrozamine
Epoxizi - metaboliti ai:
- &nb 616k1012g sp; &nb 616k1012g sp; aflatoxina B1
- &nb 616k1012g sp; &nb 616k1012g sp; benzen, brombenzen
- &nb 616k1012g sp; &nb 616k1012g sp; furosemid
- &nb 616k1012g sp; &nb 616k1012g sp; olefine
Radicalii liberi au e - cu spin impar → reactivitate chimica foarte mare generata de:
- &nb 616k1012g sp; &nb 616k1012g sp; tetraclorura de carbon
- &nb 616k1012g sp; &nb 616k1012g sp; halotan
- &nb 616k1012g sp; &nb 616k1012g sp; brom triclormetan
- &nb 616k1012g sp; &nb 616k1012g sp; paraquat
- &nb 616k1012g sp; &nb 616k1012g sp; unele alimente
- &nb 616k1012g sp; &nb 616k1012g sp; radiatii ionizante
- &nb 616k1012g sp; &nb 616k1012g sp; inflamatii
- &nb 616k1012g sp; &nb 616k1012g sp; procese patologice
Compusi N hidroxilati:
- &nb 616k1012g sp; &nb 616k1012g sp; paracetamol - insuficienta hepatica acuta
- &nb 616k1012g sp; &nb 616k1012g sp; uretran
Nitrozamine- tub digestiv
- &nb 616k1012g sp; &nb 616k1012g sp; amine
- &nb 616k1012g sp; &nb 616k1012g sp; nitriti
Metanol → toxicitate retiniana
(tratament → blocarea metabolizarii cu alcool etilic)
Paration → metabolizare → paraoxon (paralizie neuromusculara, insuficenta respiratorie)
Chimica: - simptomatologie
- &nb 616k1012g sp; &nb 616k1012g sp; data de interactiunea toxicului cu receptorul
- &nb 616k1012g sp; &nb 616k1012g sp; nu toate substantele au receptor in organism
- &nb 616k1012g sp; &nb 616k1012g sp; xenonul produce narcoza prin mecanism fizic (nu are receptor) → clatratii structureaza apa celulara
- &nb 616k1012g sp; &nb 616k1012g sp; receptor toxodinamic (proxtigmina → tratament miastenia gravis)
Receptor |
Substante |
Mecanism |
Colinesteraze |
Compusi organofosforici |
Blocarea centrului esteraza |
Citocrom oxidaza |
Cianuri |
Blocarea transportului de e- la nivelul lantului respirator |
Grupari tiol enzimatice |
Metale grele |
Inactivarea gruparii tiolice |
Hemoglobina |
CO, nitriti, nitrati |
Formare carboxihemoglobina, methemoglobina |
Acizi nucleici |
Alchilante, radiomimetrice |
Blocarea sintezei acizilor nucleici |
Receptori nicotinici |
Nicotina, curarizante |
Stimulare directa, blocare, paralizie |
Lipide structurale |
ClC4 |
Radicali liberi |
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