I can understand your concern, but dont worry as colicaid wont cause drowsiness...

For how long baby is not waking up for milk? Colicaid usually doesn't cause drowsiness And colicaid needs not to be given regularly.. it's advisable only when baby is crying so much even after feeding ..usually that happens in the evening time ... at this age if baby is sleeping even for 3 to 4 hours you can allow baby sleep because if the tummy is full then only baby will have that long sleep . so baby should be fed only on demand

First 3 months even if the baby is sleeping, please wake them up and feed or just feed somehow within 2and half hours. Burping after every feed reduces colic pains. Here colic aid worked so must have slept well. Kids sleep a lot in first few months. Prolonged sleep without feeds may reduce sugar levels and can lead to brain damage.

Simethicone causes some amount of drowsiness and it should not be given regularly in children.

Colicaid  per se doesn't cause drowsiness .But if the child has been irritable and having disturbed   sleep due to stomach issue ,giving colicaid would have relived the baby and resulted in sleeping for longer time .