Unlike the split horizon with poison reverse, route poisoning provides for sending updates with unreachable hop counts immediately to all the nodes in the network.
This makes all nodes on the invalid route seem infinitely distant, preventing any of the routers from sending packets over the invalid route.
[1] Some distance-vector routing protocols, such as RIP, use a maximum hop count to determine how many routers the traffic must go through to reach the destination.
A route is considered unreachable if the hop count exceeds the maximum allowed.
This prevents routing loops, improving the overall efficiency of the network.