We are air traveling with are 5 month old to his grand parents ...it will take 24 hours from door-to-door?

One of our friend advised us to give a medicine which is generally given for colic to make the sleep through -out journey......she gave it to her daughter when she was 3 months old and taking a long flight...she slept for 9 hours straight!!!!!!!!! the girl 3 years now and Absolutely fine!!!! any experiences on this??? wht do you advise?