hello and welcome to HCM,
Any drug can have side effects and the same is true for your anti allergy
medications also. However having treated lakhs of patients for years with the same combination you mentioned, i can safely say that overall they have very little side effects and they are very well tolerated by many.
Furthermore if you are having good control of your allergy then i would advice you to first take only the levocetrizine daily (2m) and then alternate days (2m) and then after every two days (2m) over a period of six months..........in this way your dependence on the drug will reduce and also the chance of side effects.
Sometimes rarely though even sexual dysfunction
has been noted with both the drugs but you cannot definitely say that in any way. Meet a sexologist
to confirm that
Dr Sriram Nathan