Table of Contents

Chlorinated hydrocarbon insecticides:
Organophosphorus insecticides:
Carbamate insecticides:
Botanical insecticides:

insecticides

see also: acetylcholinesterase inhibitor poisoning - organophosphate insecticides, etc, toxicology, pharmacology main index

Chlorinated hydrocarbon insecticides:

4 groups:

i) DDT & its analogues:

DDT, methoxychlor, TDE

ii) benzene hexachlorides:

BHC, lindane

iii) cyclodienes:

aldrin, chlordane, diedrin, heptachlor

iv) toxaphenes

toxaphene (campheclor)

acute toxicity:

Na channel blockade → rapid repetitive firing in most neurons
Ca channel blockade
⇒ CNS stimulation → tremor, convulsions

chronic exposure:

⇒ carcinogenic in animals but not established in humans

Organophosphorus insecticides:

'irreversible' acetylcholinesterase inhibitors
see acetylcholinesterase inhibitor poisoning - organophosphate insecticides, etc

Carbamate insecticides:

'irreversible' acetylcholinesterase inhibitors via carbamoylation of the esteratic site
toxicity as for organophosphates but pralidoxime not usually advised as antidote
see acetylcholinesterase inhibitor poisoning - organophosphate insecticides, etc

Botanical insecticides:

nicotine alkaloid
- rapidly absorbed mucosa & skin
- ⇒ stimulates acetylcholine receptors:
  - sympathetic & parasympathetic ganglia
  - neuromuscular junctions → depolarising blockade
rotenone
- ⇒ GIT irritation if ingested
pyrethrum
- ⇒ if substantial ingestion/inhalation then risk of CNS excitation/convulsions & tetanic paralysis via Na channel mechanism similar to DDT
- ⇒ contact dermatitis