quick question about anti biotics

[migola]

DD is on anti biotics & recent lot should have been given at 3.30. She's still asleep & I would like to let her sleep some more - how 'late' can I give her the ABs? Will it make a difference? It's a once every 8 hours AB

thanks. I woke her up eventually so it was only half an hour late (& the next dose I gave half an hour 'late' too