Reversal of organophosphate-induced muscle block by neomycin.

The organophosphate, diisopropyl fluorophosphate, and the aminoglycoside antibiotic, neomycin, both independently block neuromuscular transmission. At the neuromuscular junction, neomycin reduces the presynaptic release of acetylcholine, whereas diisopropyl fluorophosphate irreversibly inhibits acetylcholinesterase, thereby increasing the acetylcholine concentration. In the rat diaphragm preparation, the block in neuromuscular transmission caused by diisopropyl fluorophosphate could be reversed by adding neomycin.