Safe is relative terminology; it depends on your general Condition, any other medicines if you are taking or not; your
liver and
kidney functions etc.. - but it is very commonly prescribed combination of levocetrizine + montelukast - so if you are healthy otherwise and not on any medications, you should be ok. Especially if it is just 1 or 2 doses.
Next Steps
Consultation is always advisable especially if you are having any known medical conditions for which you require daily medications, or if you have any significant allergy history.
Health Tips
these medicines can cause sleepiness in some individuals so if you do take it ,then avoid any activities which requires active attention e.g. Driving.