No formal in vivo drug-drug interaction studies have been performed with levocetirizine. Drug interaction studies have been performed with racemic cetirizine.
Alcohol, CNS depressants
Additive CNS depressant effects; concurrent use should be avoided.
Food had no effect on the extent of levocetirizine exposure; however, the half-life was delayed about 1.25 hours and the Cmax was decreased about 36% after administration with a high-fat meal. Levocetirizine may be taken without regard to food.
Cetirizine AUC and half-life may be increased, while Cl may be decreased. The risk of adverse reactions may be increased.