All sedatives require discussion with the doc before you use them. Sudafed (pseudoephedrine) is sedative (especially when taken with alcohol) as well as being a decongestant. Some formulations also contain a stimulant (frequently caffeine) to reduce the sedative effect. Xylometazoline spray (Otrivine) is not sedative as it is administered topically and not systemically.
There is a list of drugs approved and banned in aircrew. It's probably in AP1269 but as I haven't seen a copy for about 10 years (we don't regularly have recourse to it in anaesthetics!)
Generally any drug should be discussed with the doc (although I think you are probably safe with paracetamol!).
Lariam (Mefloquine) causes all sorts of very odd side effects (up to and including florid psychosis) in about 10% of patients so is generally not recommended in aircrew. The specific agent used depends on where you are going and how soon. The last time I had a short notice trip to Sierra Leone (<48 h notice), we were given Malarone.
HTH
BtD