Where you should spend the night in Managua [1] depends a lot on your reason for spending the night here. If all you need is the cheapest possible bed before boarding an international bus to a neighboring country, the hospedaje scene in Barrio Martha Quezada is probably your best bet.
But if you’re overnighting in order to make an early morning flight there are safer options elsewhere, especially if you’re willing to spend a few extra dollars. You can catch an early-morning taxi to the airport from anywhere in the city, or you can roll out of bed at the Best Western La Mercedes and walk across the street to check in.
Links:
[1] http://www.moon.com/destinations/nicaragua/managua